Why do kohanim always chant in a terrible monotone?

Question: I am not sure if it is just me, but it seems that there is never a melodious chanting of birchas kohanim, but rather is always a mixture of many toneless voices, as if they are tone-deaf. Is this for a reason? Do others share this experience? Should a kohen not sing more melodiously than the others? In Ten Minute Halacha - Looking at Hands of Kohanim During Birchas Kohanim Rabbi Aryeh Lebowitz brings down sources that say that the reason not to look at their hands is because maybe there are blemishes of some sort on their hands and it would be embarrassing for them. Maybe this is a similar reason? That is, to not embarrass kohanim who do not have a good voice? Practical application: Would it be improper for someone to think they know better than everyone else and show off their voice, because really they aren't supposed to sing like that? Does that person deserve rebuke, or are they doing a good thing?
Comment: You say, " it seems that there is never a melodious chanting of birchas kohanim, but rather is always a mixture of many toneless voices" but that is just your personal perception based on your limited experience. Try asking about whether there is any halachic basis for not being overly melodious in presentation instead of accusing kohanim of having voices that don't live up to your personal standards.
Comment: Why was I downvoted?? I was asking a sincere question!
Answer: I understand that not all Kohanim (or anyone else) have the most beautiful and melodious voices, but I believe that you are missing the whole point in focusing on this alone. It's the words and deed which matter most, not the voice they come from.
I have seen people pray and sing with the upmost beauty and fervor. Not because they possessed the voice of David HaMelekh, but because they possessed the same passion and devotion as him.
I didn't downvote you, but I understand both yourself and those who did. It's not that your question isn't sincere, it's simply that it's matter is not of great importance.
Peace and blessings brother!
Comment: Really where I was coming from in asking the question was: would it be improper for someone to think they are better than everyone else and show off their voice, when really they aren't *supposed* to sing like that?
Comment: Should this not be a comment?
Comment: I get you, but I think it's probably just the sound of their voice. Perhaps there is a reason depending upon the community, but I have heard Kohanim with the voice of angels before. So perhaps it is more so the individuals voice, than any custom.
Comment: Indeed we should never show off though, especially in religious matters. I remember being rebuked for wearing white on Shabbat (for Kabbalistic reasons) when I was younger. This wasn't because any sin, in fact there is great merit in it, rather because it made me stand out and "show off" to everyone else.
Comment: @Dov I assume you mean my answer. I didn't have enough reputation to comment everywhere just yet, so I had to use the means I had haha.
Answer: The singing is meant to mark time while the congregants say the prayers in the siddur. (On Shabbos, when those prayers are not said, the singing is omitted.) The Kohanim are trying to mainly stay together and keep a standard pace that will allow the congregation to finish, not put on a show. So if the singing sounds more functional than usual synagogue singing, that is because it is.


Expectation value of pure state in quantum mechanics

Question: It's well known that in quantum mechanics, the expectation value of a self-adojint operator $A$ in pure state  $|\psi\rangle$ is  $\langle\psi |A|\psi\rangle = \operatorname{Tr}(A |\psi \rangle \langle\psi |)$.
My question: why this equality holds?
I can't see it. I am also unable to find the proof anywhere.
Comment: This is an application of the cyclic invariance of the trace: $\langle\psi |A|\psi\rangle = \operatorname{Tr}(\langle\psi |A|\psi\rangle)=\operatorname{Tr}(A |\psi \rangle \langle\psi |)$. Are you familiar with that property?
Answer: I'll prove the following fact which you may find useful in general: Let $A$ and $B$ be two matrices.  If either of the products $AB$ or $BA$ is well-defined and square, then they both are, and $\mathrm{Tr}(AB)=\mathrm{Tr}(BA)$.
Proof: That $AB$ is well-defined and square means that $B$ is the same shape as the transpose of $A$, so $BA$ is also well-defined and square.  So let $A$ have dimensions $m\times n$ and $B$ have dimensions $n\times m$.  Then the trace of $AB$ is $\sum_{i=1}^m (AB)_{ii} = \sum_{i=1}^m\sum_{j=1}^n a_{ij} b_{ji}$, and interchanging the order of summations we get $\sum_{j=1}^n \sum_{i=1}^m b_{ji}a_{ij} = \sum_{j=1}^n(BA)_{jj}$, which is the trace of $BA$.
In your case, you just need to apply this result to the matrices $\langle\psi|$ and $A|\psi\rangle$: you obtain $\mathrm{Tr}(A|\psi\rangle\langle\psi|) = \mathrm{Tr}(\langle\psi|A|\psi\rangle) = \langle\psi|A|\psi\rangle$, since the latter is just a number.
Answer: Given a pure state $| \psi \rangle$ in a Hilbert space $\mathcal{H},$ how is the expectation of an observable $A$ calculated? From your question we know of two compatible methods, i.e. $\langle \psi | A | \psi \rangle$ or $\mbox{Tr} (A | \psi \rangle \langle \psi |),$ where $\mbox{Tr}$ denotes the trace. How is equivalence shown?
Let's start with evaluation of the latter, namely
$$Tr (A | \psi \rangle \langle \psi |) = \sum_{j} \langle j | A | \psi \rangle \langle\psi | j \rangle.$$
We have used the Gram-Schmidt procedure to extend $|\psi \rangle$ to an orthonormal basis $| j \rangle$ which includes $| \psi \rangle$ as the first element. Now, we can take advantage of commutativity to write
$$\sum_{j} \langle j | A | \psi \rangle \langle\psi | j \rangle = \sum_{j} \langle\psi | j \rangle \langle j | A | \psi \rangle.$$
Lastly, we use the resolution of the identity, i.e.
$$\sum_{j} \langle\psi | j \rangle \langle j | A | \psi \rangle = \langle \psi | A | \psi \rangle.$$


Shutdown from terminal without remembering open windows

Question: If I shutdown/reboot from Menu I get an option of saving state of open windows or not, but if I issue a command from terminal say shutdown -h now it will shutdown remembering all open windows, how can I shutdown without remembering any of the open windows just like the Menu option from terminal ?
Answer: I am searching for a solution to the same problem. I have not found a nice solution although there is a hacky one here which in short is:
Disable saving application state:
rm -r '~/Library/Saved Application State/*'
chmod -R a-w '~/Library/Saved Application State'

Disable 'Reopen windows when logging back in':
defaults write com.apple.loginwindow TALLogoutSavesState -bool false
chmod a-w ~/Library/Preferences/com.apple.loginwindow.plist
sudo chown root ~/Library/Preferences/com.apple.loginwindow.plist

See the provided link for more details.
But I really hope there is some better solution to this ? In my case the problem is that I have a mac in a server room that automatically runs a script in a terminal window. This machine can be rebooted remotely. But thus every time it reboots it keeps the old terminal window and opens a new one, so if I have rebooted it 10 times there will be 10 terminal windows open where only one is in use.
Comment: I have this same problem in 2022 on Catalina.  Is there no better solution still??  Drives me crazy, my remote server reboots every night and runs a script in Terminal on boot, so over time I end up with a gajillion terminal windows open.  Right now I end up closing them all manually every few days, really annoying!
Answer: I believe the keyboard shortcut controloptioncommandeject has the same effect.
When you press all four keys the Mac starts the shutdown process, only prompting you to save documents/projects that have changes as their corresponding applications shut down.


Should I ask for a Letter of Rec from a Newer or Older Colleague?

Question: I want to apply for a program where I will be doing research in a particular area for roughly 6 months.  This is an area of research I'm very deeply interested in, but I don't have any experience yet.  The program asks for a letter of recommendation and I'm a little torn who to ask to write this letter for me.  I'm currently a visiting assistant professor at a college and I have a colleague in my department who knows about my interest, but he's honestly someone who isn't super familiar with my work.  He's offered to write a letter with the caveat that this would be a relatively weak (albeit positive) letter.  On the other hand, I'm considering asking my thesis adviser to write a letter for me.  My concern however is that this would like like I'm relying too much on my grad school experience to get me into this program (it's been almost 2 years since I finished my PhD).  Unfortunately neither one will be able to speak that much to my experience in the intended area of research (since I have none).  Are there merits to relying on a newer colleague at this juncture, or is it safer to rely on someone more familiar with my work?
Comment: I assume that your skills, if not your direct experience, will be useful in the new area.
Comment: @Buffy Yes, i definitely have the prerequisite skills to enter this field, it's just new for me.
Comment: What have you been doing in the 2 years since grad school?
Comment: @user151413 adjuncted for a year, and just secured a full time position last August.  Fall semester was too teaching intensive for me to work in research.  On top of that, I went to a very small grad school with little funding and didn't make any collaborators during my time there.  Trying to change that now.
Comment: Ok. But if you want the last two years to be accounted for when assessing your application, it makes sense to have a letter from someone who can assess that time (can be your PhD advisor, but only if he/she can in fact assess it).
Answer: You want letters from the people who know your work best. At this point that is probably your thesis advisor, with whom you have actually done research, even though in a different area. Be sure to explain your new interest when you ask your advisor for that letter.
Recommendation letter from CS faculty for math grad school (and vice versa)
Comment: Yes, always from those who know you best. Preferably those who have worked with you.
Comment: Not clear that someone who knew you best 2 years ago (even better than anyone knows you now) is the best person to write a letter. After all, what people did *recently* matters, not what they did X years ago.
Comment: @user151413 Depends on the work you've done with the person who knows you more recently. The OP says not much in this case.
Comment: @Ethan Indeed, just saying that it is not clear in this case.


What is the timeline for G1 Transformers?

Question: I know that when you read this question at first you're thinking what are you talking about? So let me explain: They land on earth and later awaken in 1984. And somehow years later it's 2005! The only episode that tells us it's 2000, is 'Trans-Europe Express'. And the series ends in like summer of 2006. So, where do all the episodes or battles take place on the timeline according to the G1 Transformers?
Comment: Which series are you talking about? I assume it is TV not the comics (there are multiple universes and hence multiple timelines).
Comment: Yes I am talking about the TV series.
Answer: Seasons 1 and 2 take place in 1984 and 1985.
The episode 'Trans-Europe Express' also takes place in 1985. The race was called 'Europa 2000' because the course was about 2000 miles.
Then, 'Transformers: The Movie' occurs in 2005, 20 years after season 2.
Season 3 takes place shortly after 'The Movie' and season 4 (just one 3-part episode) ends in 2007 (according to the transformers wiki).
You can notice the 20 year difference because Spike is a boy during the first two seasons but a grown man during season 3.
Comment: Well there's nothing wrong with being one. Thanks! :)
Comment: I guess I'm a nerd ;)
Comment: The map of the Europa 2000 has some [very interesting implications](http://tfwiki.net/wiki/Europa_2000) about the political state of Europe in the G1 universe.
Comment: Okay, Because it gets a little confusing along the lines of dates and where episodes fit in. And it helps to know these things if you are a nerd of transformers.


PDF items are not getting indexed and not listed in multilist with search

Question: I have upgraded Sitecore 8.1 to 9.1 and now in 9.1 PDF items are not getting indexed and also they are not getting listed in a multilist with search field.
Comment: Did you include pdf template in index file? What is a root path of index?
Comment: Which index are you using? Azure/Solr,? And which one were you using on 8.1?
Comment: currently solr and with 8.1 Lucene
Answer: Sounds like you are missing the needed IFilter to index pdf content. Check https://doc.sitecore.com/developers/91/platform-administration-and-architecture/en/index-pdf-files.html for the information on 9.1:

The Sitecore Content Search API uses the native Microsoft Windows
  IFilter interface to extract the text content from media files for
  indexing.
However, to enable the Sitecore Content Search API to properly index
  the content in Adobe PDF files, you must install the Adobe PDF IFilter
  on every content management and content delivery server.
Currently, Sitecore only supports Adobe PDF IFilter version 9.
You can install Adobe PDF IFilter as a standalone IFilter or as part
  of Adobe Acrobat Reader. You can download Adobe PDF IFilter version 9
  from ftp://ftp.adobe.com/pub/adobe/acrobat/win/9.x/.


If stains/traces of madhiy remain on garment after sprinkling water over it, does it matter?

Question: We know that if we sprinkle a handful of water over madhiy on a garment, it is sufficient according to the most authentic opinion. But I have a doubt. If stains or traces of madhiy still remain after sprinkling the water, do I have to sprinkle water again in that area? Or is sprinkling a handful of water once sufficient regardless of the stains or traces of madhiy that remain? And is the water that was splashed on madhiy pure?
Answer: Water is regarded in fiqh as having the attribute to be tahir: clean
Moreover it is regarded as

tahir mutahhir
طاهر مُطَهِّر

meaning it is clean طاهر (by itself) and cleaning مُطَهِّر (anything which comes in contact with it).
We could also say madhiy (a spot) usually is less the quantity of water  (a handful) used for the act of cleaning therefore the water used in such a case is still regarded as tahir in the majority view.
But we know from fiqh and from hadith sources that the only requirement for removing or maybe it is better to say handle madhiy is by sprinkling water over it. This requirement was nowhere extended to remove the traces of madhiy (if madhiy is regarded as najasah then this would be a special case).
Therefore the above discussion can be closed by saying handling madhiy is done and fulfilled by only sprinkling water over it there's no necessity to remove it or its traces.
As to the topic of stains of najasa it was already discussed in the following posts:

Semen Stains Remaining On Clothes Even After thoroughly Washing The Garment
is pus and blood najis

And what must be cleaned or removed, if najasah (color, odor and taste)  is removed is explained in:
Ritual impurity in pants
Comment: So the conclusion is that even if traces of madhiy remain after splashing water it is still pure right?
Comment: I would like to specifically know about madhiy, not about blood, pus or semen as those have different rulings regarding cleaning them. If stains of madhiy remain after sprinkling water do I have to sprinkle water again or does it become tahir? Just a simple clarification would do.
Comment: @user2007 there's nothing specific a najasah is a najasah and the way of cleaning is the same.
Comment: And also the way of cleaning blood, semen and madhiy is definitely different as human blood or pus (except if it comes out from the private parts) and semen is pure according to the more authentic opinion. And the way of cleaning madhiy is sprinkling water. The way of cleaning urine is washing it. Even if one wants to clean semen for just cleanliness it is to be scratched off if dry or washed if wet. But please clarify the conclusion here.
Comment: The way of cleaning means removing it's color, odor and taste as good as possible. This is what fiqh agrees upon as about how you do it that's up to you in any case.
Answer: Sheikh 'Assim in a YouTube video said:

Sprinkling it does the job even if there are marks. Ignore it and pray with it.

This fatwa on Islamweb also says it is sufficient to sprinkle water over it according to some scholars.

There is no doubt that "sprinkling water does not remove the impurity," as Ibn Qudaamah  may  Allaah  have  mercy  upon  him said, but some scholars are anyway of the view that it is sufficient to sprinkle water over it in order not to cause hardship and embarrassment, pursuant to the Ahaadeeth that provide that sprinkling water is enough, like the Hadeeth: "….what about that clothes it touches? and the Prophet  sallallaahu  `alayhi  wa  sallam ( may  Allaah exalt his mention ) replied: It is enough for you to take a handful of water and splash it over the part of your clothes that you see it has touched." [Abu Daawood] And the Hadeeth narrated by 'Ali  may  Allaah  be  pleased  with  him about Mathy which reads: "… and splash water over your genitals."

Hopefully this answers the question. And Allah knows the best.


Bleach in turtle tank

Question: We had a terrible outbreak of algae in the turtle tank.  I removed the turtle and added bleach to the water to kill the algae. I then siphoned all but about an inch of the water out, put in clean water, and conditioned the water. I still smell bleach.  I am unable to completely empty the tank of water. What do I need to do?
Comment: Hi, why exactly are you unable to completely empty the tank?
Comment: In over 70 years with fish , i have never used bleach . i guess the turtle wont get covid virus.
Comment: you could repeat the process about a gorillian times until the bleach is diluted to harmless levels. but this will take a very very very long time
Answer: Bleach is extremely toxic to all aquatic life and even minuscule amounts of it - way below the concentration threshold needed for a human to smell its presence in water - could be harmful. Being able to actually smell its presence in water means that the danger level of its concentration is completely off charts and you definitely need to decontaminate the whole tank for the sake of safety of your turtle. I know that's what you explicitly said you are unable to do, but I honestly just don't see any other reasonable option in this case.
I assume that having conditioned the water means you've used aquarium water conditioner from pet store, meant to neutralize chlorine and chloramines present in tap water. Aquarium water conditioners are capable of neutralizing bleach (which is a water solution of hypochlorite salt), but they are made to reliably neutralize the specific and minuscule concentrations of chlorine and chloramine found in the tap water, so I wouldn't trust them to reliably neutralize the unknown amount of bleach that is present in your aquarium water. It neutralizes chlorine and its mentioned compounds by reacting with them, so it's being consumed in the process - and it might be the case that the amount of active ingredient in water conditioner is too small for the amount of bleach. Nonetheless, using the dechlorination conditioner was definitely better than nothing.
Active dechlorinating ingredient in aquarium conditioners is sodium thiosulfate (Na2S2O3). It is visually similar in appearance to table salt, is relatively non-toxic, non-expensive and should be easily available online; besides that, you could also ask for it in photographic studios that deal with physical photographic media (sodium thiosulfate is used in photographic processing of film and paper) and in pharmacies (it is used in medicine, mainly as an antidote for cyanide poisoning and for baths intended to alleviate external fungal infections); it is also used in washing to remove stains made with tincture of iodine from clothes. I'd advise you to buy this compound (please note that it has to be pure, with no additives), prepare the saturated water solution of it (by mixing it with clean, warm water until it no longer dissolves) and then use this solution to decontaminate your aquarium.
If I were you at this point, I would completely empty the tank, thoroughly scrub its interior with a rough sponge to clean all the algae and mineral deposits that could have potentially absorbed any residues of bleach, then flush the whole tank with an energetic and constant stream of tap water for at least 15 minutes. After that, I would clean the aquarium with saturated sodium thiosulfate solution. And that's just for decontaminating the tank - any substrate, decorations, etc. I would most probably just dispose of and get new ones - especially those things that I'd even remotely suspect of being porous. I would consider them all to be potentially contaminated and dangerous at this point.
If there is something in the tank that you absolutely and ultimately don't want to throw away, like an expensive piece of equipment - I'd attempt to flush it with an energetic stream of tap water, as reliably as I could, for a reasonably long time - it's hard for me to specify for how long as that would depend of my sentiment for conserving water - but let's say, for about 15 minutes. After that, I would wash the object with saturated sodium thiosulfate solution, preferably also leave it completely submerged in a container filled with this solution for some time, allowing the thiosulfate to "soak in" and neutralize any bleach that might have been absorbed a bit deeper into the surface.
For example, if there is a filter in your aquarium: I'd flush it with running tap water, both on the inside and the outside, then wash it with thiosulfate solution and leave it submerged in it for a few hours; maybe also I'd fill some container with tap water (or preferably thiosulfate solution) and let the filter run there for some time, so it could flush itself on the inside. I'd also throw away all the filter media and replace them with brand-new ones.
Also, glass equipment - like thermometer and heater - shouldn't be impossible to decontaminate reliably, since glass is relatively inert and not porous. For these I'd go with the same scrubbing, flushing and "pickling" in thiosulfate routine as for cleaning the tank.
I have to admit that I'm a bit obsessed with all the safety measures, but please realize how serious of a threat bleach is for the life of your turtle. I've read stories about people accidentally having fatally poisoned all the fish in the tank because they had used bleach to disinfect and clean some aquarium decorations, and the minuscule amount of bleach they absorbed apparently were enough to annihilate all of them. Of course, turtles aren't fish - it gives them a little "advantage" since, unlike turtles, fish use gills for respiration and thus their respiratory system is also the subject to damage from water-dissolved chemicals. But still, all the turtle's external mucous membranes are in contact with water and thus they are vulnerable to immediate damage, especially from highly corrosive and oxidizing chemicals as bleach.
I've also read stories about people using bleach in aquarium disinfecting and cleaning, but it's done extremely carefully to completely flush it off to not contaminate the water afterwards, and it's never actually added to the water with turtles or fish. I'd never advise using it nor use it myself - the harshest "chemical" I've ever used in aquarium cleaning was table salt, so my answer might be a little biased.
Answer: I was curious about this because at this very moment I have put bleach into the turtle aquarium and did it by adding a small measure of it, like a cap full, or quarter cup at most, while I had a hose siphoning out all the water.  The turtles are safely out of the way in tubs.
The tank is 125 gallons, and no way will I empty it, ever, completely.
However, by siphoning down, and then refilling several inches at a time, the bleach level is dropping way down.
When I lived in a country where the wash water was contaminated with e. coli and worse, I learned how to batch chlorinate using a cap full of bleach to about 30 gallons.
Washed myself and all my dishes with this, and never got an infection. No more eye infections after that, no more diarrhea, and life was better.  Used properly, bleach is your friend.
But, you can't let your little charges drink bleach, either.
By the time I am done, not only is there no bleach smell at all, but after that is noticed, the water has been changed two more times.
Whatever concentration is left after that, is some ppm amount.
In an emergency, drinking water for human consumption is made using bleach.  The recommendation is to NOT drink it if after two treatments there is still no smell of the bleach.  For human consumption, a slight smell of bleach is considered necessary.
So, use your common sense.  Do the research.  Check out "water batch chlorination."  And if you ask me, turtle skin is a lot tougher than human skin, in the water.
At least the aquatic turtles I think we are talking about here.
Let's keep Trump out of this, too.
Comment: Welcome to Pets. It is mainly mucous membranes; eyes are not covered by skin and skin toughness doesn't matter in their case. Aquatic turtles spend a lot of time completely submerged in water and even trace amounts of highly oxidizing substances, like bleach, will irritate their conjunctivas and could damage them, as well as their corneas. What is more, turtles are breathing air that is in close proximity to the water and thus their lungs will be constantly exposed to trace amounts of chlorine generated by decomposition of bleach dissolved in this water. ...
Comment: ...Chlorination of water in swimming pools is safe for most people, but it still irritates our eyes and lungs. My personal experience is that I always have some transient but unpleasant eye irritation after a session at swimming pool, which lasts a few hours. Pool chlorine is also tied to lung damage in professional swimmers. And please note that people are in/near swimming pools only a fraction of their daytime, unlike aquatic turtles which are constantly near their tank water, and completely submerged most of the time.

Bleach in turtle tank


How to change Windows 10 Lock screen time format?

Question: My Windows 10's time format is 24 hour clock, this includes the taskbar but the lock screen is still 12 hour clock format. How do I change the format of my time in lockscreen?
Comment: If you would like to change the lock screen date format as well, see this thread: change date format on Win 8.1 lock screen: [http://superuser.com/questions/823244/change-date-format-on-win-8-1-lock-screen/1009995#1009995](http://superuser.com/questions/823244/change-date-format-on-win-8-1-lock-screen/1009995#1009995)
Answer: Same here; I was able to get the lock screen to show HH:MM via my personal account with admin privileges, no hidden admin account needed. This is how:

Press Win+R, type intl.cpl and press Enter (this will open "Region" settings)
Set your "Short Time" & "Long Time" formats in the window that comes up, then click "Apply."
Select the "Administrative" tab at the top, then click the "Copy settings..." button.
In the subsequent window, check the box for "Welcome screen and system accounts."
Click the "OK" button and lock the PC with Win+L to test it.
Comment: + for not using tons of screenshots
Comment: Even if you are totally logged off?
Comment: Just to confirm this worked. Even after rebooting the lock screen had the 24 hour format. Thanks.
Comment: I believe that between **Copy settings...** and **OK** you also have to check the box next to **Welcome screen and system accounts**--otherwise you're not changing anything, no?
Comment: Unfortunately this didn't work for me :/
Comment: For me this works for time, but not for date...
Comment: That may be the weirdest Windows behaviour I've ever seen. The fix worked for me.
Comment: Works like a charm. :) Thanks,
Comment: Thank you! Worked for me.
Answer: I've figured out a better answer than hacking the registry...  Thanks to zppinto for putting me on the right track.  The problem remained that the time format was still US when no user is logged in.
First activate the hidden administrator user account:

Run the Command Prompt as administrator
Type in net user to see all the user accounts
Type in net user administrator /active:yes to activate the hidden administrator user account
Type in net user administrator * to give the administrator user a password - always a good idea
Press Ctrl+Alt+Del to Switch users (or logout and log into Administrator account.
In the administrator account:

Open the control panel and click on Change date, time or number format

Change the Format: on the Formats tab and click on Additional Settings... button (Note: you may want to do language thing here as well, in order to copy it over to the Welcome Screen, etc)

Click on Time tab and make sure the correct time format is being used (also the date format, etc)

Back on the Region dialogue box click on the Administrative tab and click on Copy settings... button

Tick the Welcome screen and system accounts and New user accounts check box to copy the settings to all the Welcome Screen

Note: my settings took a long time to copy over; thus be a little patient - as the doctor said to the dwarf
Comment: Thank you very much for the detailed explanation. I am very annoyed by the 12-hour format on my lock screen. Finally it's fixed!
Comment: You don't have to activate the built-in Administrator account, any administrator account will do. I just did that (starting from "In the administrator account") on my PC -- from my own personal, administrator account -- and it worked. (I had the exact same problem)
Comment: Actually, I had to activate the built-in Admin. I didn't have the button to copy the settings to the welcome screen and I am an Admin user :s  Believe me; I've tried a lot of things before getting to this point. The problem is the Date/Time format before you log in is US (The only country to use that format? but we all have to?)
Answer: Have you tried to:

Go to "Settings" -> "Language and Time" -> and on "format" -> "change date and time formats"?
Or go to "Control Panel" -> "clock, language and region" -> "change date formats, time or number" and then change the format? You can also have look at "Additional settings" on that window to see if everything is formatted as expected.

If none of that works, I think only solution will be editing the windows registry. There are some tutorials for Windows 8. I think it will be compatible with Windows 10 too.
Comment: Hum... And the registry key "Clock" is set to "24HourClock"?
Comment: In all settings, including registry the short time is HH:mm, long time is HH:mm:ss
Comment: Yes it is. I've changed the owner of the Control panel (http://www.eightforums.com/tutorials/2808-take-ownership-file-folder-drive-registry-key-windows-8-a.html) in order to change permissions of LocaleInfo (still couldn't change LocaleInfo's permissions) but now it shows 24 hour clock :s weird - seems that we are supposed to be too stupid to change the display clock
Answer: PowerShell method:
New-PSDrive -Name HKU -PSProvider Registry -Root HKEY_USERS | Out-Null
$internationalPaths = @("HKU:\.DEFAULT\Control Panel\International","HKCU:\Control Panel\International")
$hourFormat = "h"
IF($TimeFormat -eq '24h')
{
    $hourFormat = "H"
}
FOREACH ($path in $internationalPaths)
{
    IF((Get-ItemProperty $path).'sTimeFormat')
    {
        #Windows 10 default time format h:mm:ss tt
        Set-ItemProperty -Path $path -Name "sTimeFormat" -Value "$hourFormat`:mm:ss tt"
    }
    IF((Get-ItemProperty $path).'sShortTime')
    {
        #Windows 10 default time format h:mm tt
        Set-ItemProperty -Path $path -Name "sShortTime" -Value "$hourFormat`:mm tt"
    }
}

More details How to change Windows 10 Lock screen time format by PowerShell
Answer: Thanks to the PowerShell code provided by frank.
Heres what I ended up with, a bit shorter and cleaner IMO.
[string[]]$('Registry::HKEY_USERS\.DEFAULT\Control Panel\International','Registry::HKEY_CURRENT_USER\Control Panel\International').ForEach{
    # Country
    $null = Set-ItemProperty -Path $_ -Name 'iCountry' -Value '47' -Type 'String' -Force
    $null = Set-ItemProperty -Path $_ -Name 'sCountry' -Value 'Norway' -Type 'String' -Force
    # Date
    $null = Set-ItemProperty -Path $_ -Name 'sLongDate' -Value 'dddd dd. MMMM yyyy' -Type 'String' -Force
    $null = Set-ItemProperty -Path $_ -Name 'sShortDate' -Value 'dd.MM.yyyy' -Type 'String' -Force
    # Decimal
    $null = Set-ItemProperty -Path $_ -Name 'sDecimal' -Value '.' -Type 'String' -Force
    $null = Set-ItemProperty -Path $_ -Name 'sMonDecimalSep' -Value ',' -Type 'String' -Force
    # Time
    $null = Set-ItemProperty -Path $_ -Name 'sTimeFormat' -Value 'HH:mm:ss' -Type 'String' -Force
    $null = Set-ItemProperty -Path $_ -Name 'sShortTime' -Value 'HH:mm' -Type 'String' -Force
    $null = Set-ItemProperty -Path $_ -Name 'sYearMonth' -Value 'MMMM yyyy' -Type 'String' -Force
}

Answer: A simpler solution which worked for me wanting to display it in 24hr format in the UK.

Navigate to the Control Panel
Click on Region
Change the Format from English (United Kingdom) to English (United States)
Click Apply
Change the Format back to English (United Kingdom)
Click Apply, then click OK

Inherently there is something behind the scenes with Windows which changes the date and time format at a system level, despite still displaying it in the correct UK format at the front end.  I'm led to believe this is for Windows updates as it connects to US servers which needs the US format.  I work with Time and Attendance software and this has been an issue for us since Vista and still there in Windows 10 (though less aggressively).  I've just done this on my new PC and it worked, though time will tell if Windows Updates changes it back.


SP_Search account help needed

Question: I installed new search service application using powershell. "sp_sapool" is the service application pool account which i used. Everything installed fine. Topology is activated, i changed default content access account to be "sp_crawl".
But when i changed under "Configure service accounts" following: "Windows service - Search Host Controller" and "SharePoint Server Search" to use "sp_search" account, which is normal domain user account without any rights, my topology is not showing up anymore, instead it says "Unable to retrieve topology component health states. This may be because the admin component is not up and running."
Do i have to assign some db rights for the "sp_search" account?
Comment: Also, when i go to "manage services on server" i see that Search Query and Site Settings Service is stopped. "Search Host Controller Service " and "SharePoint Server Search" are running. Shouldn't all three be in the running status?
Answer: Use the same service account for your 'SharePoint Server Search' service as you do for all other services (MMS, UPS, etc.). This will maximize performance/reduce memory usage. Do not change the Search Host Controller away from the Farm Administrator account.
Comment: I checked now. As soon as i bring back sp_farm to be search host controller account, topology shows up fine. So, what's the catch with search host controller running under another account beside sp_farm? What rights does it need?

SP_Search account help needed


How do Germans give new words gender?

Question: How are new words assigned gender?
For instance, iPhone, Nasa, Youtube,etc. So many words are invented everyday (especially names of people, brands, products, apps). How do I (or anyone) know their gender? What about "That's a NO"? What's NEIN's gender?
Comment: And for the gender of _Nein_, you can look it up in a dictionary: http://www.duden.de/rechtschreibung/Nein
Comment: And "das iPhone", "die NASA", "Youtube".
Answer: Very much the same way as new words are invented - by inventing ;)
In German, words that have no gender simply don't make a lot of sense - So it's not "first invent the word, then think about the gender", but rather inventing both at the same time. And the invention process is not normally something that happens instantly, but rather a common trial and error process between all users of that word on what works and feels best.
Linguistics is not so much a decision or ruling "it must be that way" - But rather watching people use the language and filter out what is common and thus "correct".
The thing is a bit different when words are imported from other languages and come without a gender - In this case some common rules apply that are explained very well in this post: For new words which are often nouns who sets the gender?

How do Germans give new words gender?


Are there any rules covering selfmade gear as starting equipment on higher levels?

Question: Let's say that a player creates a 6th level character with maximum possible ranks in craft (armorsmithing) . They want to start with selfmade full plate armor.  Should they still cover the full price of the armor or just the materials, which are one third of the price?
I believe that selfmade starting gear should be less pricey than one bought on the market. On the other hand I am afraid, it could be heavily exploited, like starting with +5 adamantium battle plate armor.
Are there any books, including third parties covering how to deal with this problem?
Comment: For reference, adding a +5 enhancement bonus to any armor requires caster level 15th, and even self-crafted, *+5 adamantine full-plate* requires 18,000 gp in raw materials, which is beyond the means of a 6th-level character. So you don't need to worry about that *particular* concern so much. Still a valid question in general though.
Answer: The rules expressly allow self-made starting magic items at higher levels.
Dungeon Master's Guide (3.5) p.199 gives the official rules for starting a new character above 1st level. The most relevant section is under Magic Items as Gear:

Character-Created Magic Items: A PC spellcaster created at a level higher than 1st can use any of the XP and gp you have awarded to make magic items, provided that she has the proper item creation feats and prerequisites.

However, advice on what items to allow are also given, with particular guidance on avoiding PCs spending all their starting wealth with one overpowered item.

You're free to limit what magic items characters can choose when they create characters of higher levels, just as if you were assigning those items to treasure hoards in the game. You can exercise an item-by-item veto, but an easier method is to use a maximum cost for a single item as a limit. [...] You could also limit characters to a certain type of magic item.
Comment: @KRyan To be perfectly honest, I have no idea what *as if you were assigning those items to treasure hoards in the game* even means.
Comment: Since the latter is "as if you were assigning those items to treasure hoards in the game," it does not seem like it would apply to player-made items.
Comment: @HeyICanChan It means that the DM creates all the stuff in the world and says where it is, and so determines what stuff is available. So, you are under no obligation to place Thor's Belt anywhere in the world at all, let alone anywhere accessible to characters. Character creation does not magically bypass the DM's determinations. I don't know why its worded that way though.
Comment: Regarding the limit per item; my rule of thumbs for wealth spread is either quarters or thirds. Quarters: 1/4 of wealth spent on weapons, 1/4 on protections, 1/4 on miscellaneous (Handy Haversack...) and 1/4 on consumables (wands, staves). Thirds: 1/3 on weapons, 1/3 on protections, 1/3 on miscellaneous and consumables. Quarters is more for casters/skill monkeys and Thirds for melees. I would encourage anyone to think of what happens if THE big item of a character is destroyed, lost or stolen; if the character is powerless without it, too much wealth was concentrated.
Comment: The official split is 40% on weapon(s), 20% armour, 20% shield, 20% miscellaneous. I cannot remember where I read that, however. IIRC, it was part of an official text on the balance assumptions of 3.5.
Answer: Character creation does not happen in the way that a 6th level character pops into existence with a huge bag of gold pieces and then goes to the ACME store and buy stuff. The price of an item at character creation represents the value. The fact that the character is able to create it just provides one way to explain why he has the item and it can also give good roleplaying opportunities. But I don't see why they should get it cheaper.
It's all in the past, and the money only represents the value, the origin is irrelevant.
Comment: Investing in the character options (feats, skills) required in order to be able to make items (and, in the case of magical items, paying the XP cost for them!) is why they should have to pay less money for the items. For such characters having these items has cost them more than just the money they paid for the materials.
Comment: @Carcer and they'll be able to use those skills when in the game. The starting gear value should be the same for everyone.


Video Streaming connection speed

Question: What is the required upload speed I need to stream HD video on web?
Curently I am in process of talking to various ISPs so I can find the best solution, but seems like they can't help me since a lot of them are offering low upload speed connections.
Answer: It depends on a lot of details you haven't covered here. You need about 3 Mbps to have sufficient overhead to maintain a well compressed 720p stream (the quality that Hulu Plus uses), but you would need specialized hardware to keep a good quality 720p stream encoding on the fly.  Most likely, you are going to be looking at significantly more than that if you are trying to software or CUDA encode on the fly since it won't be able to get as high of quality with as little data.
Note that this is only talking about sending the feed to a single system as well.  The most common case for distributing to multiple viewers is to encode and upload to either a CDN (content distribution network) or your own live streaming server that is in a data center somewhere.  With that kind of a setup, your one connection can be replicated out over a 100Mbps or 1000Mbps connection to many more viewers.
You can use overly compressed settings to reduce the bandwidth needs further, but it will start showing as a really noticeable reduction in meaningful resolution.  There might still be an HD number of pixels, but they won't have the kind of detail you'd normally expect from HD since it would be over-compressed.
There can be a lot of variation on that too though.  If you are live-streaming something that isn't real life, compression tricks can be used to make it much more highly compressed for example, so this still isn't a one size fits all answer, but it covers the general live video streaming case for professional level quality.
Comment: First of all, thank you for answer and sorry for late responding.
I will stream my screen to Twitch.tv (Games Streaming Platform), so basicaly I will connect to their server and they will send to third-party users my screen, so I guess I don't need 100-1000Mbps connection speed for that.
I am going to get 4Mpbs upload speed in next couple of days from my ISP and I hope that will be enough for, at least, streaming 720p videos?
Btw, my hardware is I5 Intel procesor, integrated Video card and 8gb DDR3
Comment: @Nidzaaaa - I expect you will not be able to encode fast enough for an on-the-fly stream at HD resolution with that setup, particularly when playing a game.  An integrated video card generally barely has the strength to play the game by itself and 8gb of ram isn't much for trying to run a game and encode at the same time, nor is an i5 a particularly beefy processor.  You can certainly try it and see how it goes since video games should take a little bit less work to compress, but don't be surprised if you run in to issues.
Comment: so your opinion is that my upload speed could be enough for 720p streaming, but my hardware isn't that good, right?
Comment: @Nidzaaaa - yes. That's pretty much it.

Video Streaming connection speed


how I use tor on windows phone?

Question: since the wifi that I am using does not allow me even to connect to my vpn, the only way that I have to visit facebook etc. is surfing with Tor browser, as I do on my laptop.
Is there a way to use the Tor network on my phone with windows phone 8.1?
Answer: There is currently no supported version of Tor or the Tor Browser that would allow you to connect to the Tor Network in Windows Phone. However, you can buy a Raspberry Pi and set it up as a Tor router, then to connect to that "Torified" Wifi.
Comment: This can only be done with a raspberry pi?

how I use tor on windows phone?


Voltage Regulators in Computer Power Supply?

Question: I have a damaged ATX 230WCE power supply unit and wondered if I could find 12V, 5V, and 3.3V Voltage regulators inside. I tried looking in another unknown model psu and only found transistors and diodes which looked like voltage regulators. If I can find voltage regulators, what might the part numbers be? Keep in mind, this is a very old PSU. If I won't be able to find regulator inside them, then how does it have 12v, 5v, -5v, -12v, and 3.3v outputs?
Comment: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=282
I'd check out reviews on jonnyguru for a basic disassembly/component overview of different computer PSUs. They are all built (as far as I've ever seen) quite similarly to this specific model; all PSUs I've ever seen are switch-mode supplies.
Answer: Computer supplies don't usually have integrated voltage regulators inside.  But they have all the necessary elements of a voltage regulator inside.  In a sense, the whole supply is a regulator.
There will be a voltage reference inside.  The output voltage (possibly scaled by a resistor divider) is compared to the voltage reference, and the supply is turned "up" or "down" to make it match the voltage reference.  The reference might be a TL431 or a 5.1V zener diode.
Computer supplies often regulate a main voltage (the 5V or 3.3V output) and arrange the other outputs to be ratios of the main one, by turns ratio on the transformer for example.  This is not really precise but works well enough for powering computers.
Comment: @Seif Shawkat Linear regulators aren't used because of the need to have a huge transformer and the fact that linear regulators turn all extra voltage into heat. Look up switch-mode regulator on Wikipedia for a good explanation on that (or use search on this site, there are many questions about switch-mode regulators). As for salvaging, there's a good chance that nothing will be useful or easy to use. You can only hope that the powe supply has a linear regulator somewhere inside and hope that you can find it if it's there.
Comment: Actually it's not uncommon to today find 3.3 V linear regulators inside cheaper computer PSUs connected to the 5 V rail since there's usually low demand for 3.3 V lines now. Also in some units 5 V stand-by may come from a linear regulator.
Comment: Why don't power supplies just use linear voltage regulators instead of having a bazillion components inside? And are the TL431s just programmable voltage regulators? That's what I understood from the datasheet.
Comment: Also, what could I extract that could regulate a 12v input to a 5v output from this PSU?
Answer: As AndrejaKo mentioned, you may be able to find a LM7805 (or similar) linear regulator in the 5V standby section of the PSU. Look for it near the end of the purple wire.


Sending funds from a Segwit address to a non segwit

Question: I just generated a Electrum wallet with the Segwit option on. I wonder what happens if I try to transfer SegWit -> Non-SegWit or Non-SegWit -> SegWit: Will the funds be confirmed and get transfered or will it be lost forever?
Answer:
what happens if I try to transfer SegWit -> Non-SegWit or Non-SegWit -> SegWit

As long as you are using software that supports doing so, this is perfectly possible and fine to do.

Will the funds be confirmed and get transfered or will it be lost forever?

Bitcoin can never be lost forever because of an unconfirmed transaction. For an unconfirmed transaction, the bitcoin do not move from their starting address until they are confirmed in a block. Eventually a transaction may be confirmed, or the network's nodes will remove the old unconfirmed transaction from their mempool's, and you will be able to spend the coins again. There are a few of ways to push unconfirmed transactions through, like replace-by-fee (RBF) or child-pays-for-parent (CPFP).
Comment: Thanks for the answer.  I'm asking this because I'm afraid to start using these Segwit wallets and not being able to transfer money from, for example, the Exchange wallet to my personal wallet. Being that said, how can I be sure that the Exchange wallet supports Segwit?
Comment: *'The exchange supporting segwit'* would generally refer to the exchange allowing customers to deposit funds into a segwit address controlled by the exchange. The exchange does not need to explicitly support segwit in order to send an outgoing tx to a segwit address. You do not need to worry in that regard.


Is it really true that the iPhone doesn't have turn-by-turn navigation?

Question: I'm looking into getting a new Verizon smartphone. I like many things about the iPhone, but I'm concerned that I'll have to give up a feature I really like about my current phone--turn-by-turn navigation. According to this skattertech chart, the iPhone lacks this feature. Is there really not an "app for that"? (And if not, why? The phone has GPS, so what gives?)
Answer: The thing is that the built-in Maps app uses Google Maps for the maps, and the Google Maps license doesn't allow a third-party to implement voice navigation using it.
So, Apple's Maps isn't allowed to implement voice navigation, but any other GPS software provider can offer the feature along with their own maps.
Here is a nice review of some of the GPS software available for the iPhone: http://www.macworld.com/article/156720/2011/01/gps.html
Also, that situation could change, since Apple purchased a maps company a few years ago.
Comment: One question on that link...any reason any of those navigators (besides the AT&T one) wouldn't work on the Verizon CDMA iPhone?
Answer: There are plenty of apps for that, especially in the US (where I'm not). There are the apps that mankoff suggests (I use TomTom here in NZ), but I think he left out the best value option: MotionX GPS Drive - they actually do a bunch of different applications, and all great value. Check them out.
BTW, what phone are you using at the moment? What app are you most familiar with?
Comment: Thanks, @Intuition, +1. I have an LG Dare, which is not a true smartphone (it can do mobile browsing and email, but it's very slow and there aren't many apps for it). Really the only app I've downloaded for it is VZNavigator. I'm looking to do a major upgrade here, though. I use Outlook and GMail, and need to be able to sync with those (including calendar). Other must-haves, besides turn-by-turn nav, are a fast browser and good touch-screen QWERTY keyboard (the Dare's has no error correction whatsoever). Games and video calling would be great, too.
Comment: Don't use outlook so not 100% sure about that, but it works perfectly with GMail. Of course, you can sync all of the accounts with IMAP anyway so hopefully that shouldn't be much of an issue.

There are about a zillion games available for iOS so I'm sure you'll find something to entertain yourself. I'm quite a Doodle Jump fan myself.

Good luck!
Comment: Thanks...whatever I get is gonna be way better than what I have now.
Comment: You can sync with an Exchange server, if that's what you're asking. If you mean Outlook generically, if it's syncing with your system calendar then you should be fine.
Answer: There is an app for that. Look in the App Store. I think the going rate for the GPS apps (Navigon, TomTom, etc.) is about $50 USD.
The built-in Google Maps app does have turn-by-turn (it lists the turns you need to take), but it does not have a voice, and it does not recognize when you have deviated from the suggested route and then re-program itself.
Comment: AT&T's offering has monthly fees, but none of the others do, as far as I know. Navigon, which I use, definitely does not.
Comment: Thanks, @mankoff, +1. So, it sounds like there *are* options. Do you know if TomTom, Navigon, etc. have monthly subscription fees? Verizon's "VZ-Navigator", which has audible turn-by-turn, voice recognition, traffic info, etc. costs $10/month, which is reasonable with a $15 data plan--but not so reasonable when you have to upgrade to a $30 smartphone data plan.
Comment: @DanM - I love Navigon; it's completely replaced having a dedicated GPS unit in our cars. No monthly fees—not even for live traffic updates.
Answer: The $50+ GPS apps usually include the maps in the download while the free/cheap ones download pieces of the map as required.  This is an issue if you are going to drive in areas with poor data coverage.  It's not a happy moment when your GSP doesn't have the necessary map section nd there's no reception to get it.  On the other hand, apps like TomTom (which I use) are huge (1.2GB) since they include the map so it takes up a pretty big chunk of space on your phone.
Waze is a pretty fun app but is intended to help with local driving more than trip-based navigation.  Map accuracy is crowd-sourced so the quality is wildly variable and the routing software isn't designed for long-trips.  But it's a lot of fun to use.
Live traffic usually requires a fee but it varies from product to product.
All the apps suck your battery dry at an alarming rate.  Power in the car is an absolute necessity.
Answer: Yes its true no turn by turn navigation from Apple on the iPhone, etc. However, there are many good free solutions out there and paid as well. One free solution that work currently best for local area navigation is the free Waze gps app. Works good for local under 1 hour trips and provides free traffic re routing too. Has an interesting community aka social networking aspect to it as well. Just note that with this app you are best off copying address from the maps app to Waze to best begin navigation.


How long time since a typical asteroid collided with another asteroid?

Question: How pristine and ancient are asteroids really? I suppose they melt and reform when they collide with each other. How frequently do they collide with each other?
Answer: How ancient they are, I'd have to say as old as the solar system.
Collision frequency:
Collision amongst Asteroid Belts
From ref 1  below: Based on the particle in a box model which assumes a homogeneous distribution in the interactive volume, the intrinsic collision probability is computed to be around $5 \times 10^{-18} km^{-2}yr^{-1}$.
However Wetherill(ref below) have some modifications to Opik's formulation for collision between two elliptical orbits, suggests that the impact is nearly independent of the orbital elements of the test body and is nearly half of the value obatined from PIAB model. It also seems to suggest that intrafamily collisions are higher than collision amongst non family objects.
Collision with the Earth Here it characterized in various classes:

bolides or upper atmospheric explosion,
land impacts leading to local or regional devastation,
ocean impacts leading to regional disasters,
global ecological catastrophe,
mass extinctions

Based on the scale, the impact events are categorized as harmless, Class-1, to devastating, Class-5.
The 440-KT Chelyabinsk event of 2013 belongs to impact hazard class 2, causing regional or local devastation. This was caused by a mere 20 meters wide meteor entering the atmosphere of Earth. For a cumulative number of impacts described for a given reference time interval of $T_{ref}$ = 1Ga ($10^9$ years)
which is long enough to statistically include a meaningful number of impacts from all the classesabove, the class 2 impacts cumulative will be $2\times 10^6$ , with small bodies falling in the size range of 20-100 m. Where the characteristic time scale is of $10^2$ a.
For class 3-5 events leading to regional disasters to global extinction events, the cumulative number of impacts within the reference interval is $10^4$ with characteristic time scale being $10^5$ a. These events can lead to large devastation ranging from an entire country or region (class 3, with an explosive energy of approximately 104 MT TNT), to mass extinctions (class 5 releasing an approximate energy 108 MT of TNT). An example from the history for such event is the classic K-T extinction events 65 Ma ago that wiped out more than 99% of the living species.
References:
1. http://articles.adsabs.harvard.edu//full/1992LPI....23..283D/0000283.000.html
2. http://www.springer.com/fr/book/9780792354666
3. http://onlinelibrary.wiley.com/doi/10.1029/JZ072i009p02429/abstract
(PS: If anyone has a link to the open access for final paper, or a pdf; I would really appreciate a copy.)
Comment: I might be wrong, and the frequency of collisions seems like an extremely vague question, but I fail to see how the asteroids' impact hazard category has anything to do with how often the asteroids collide?
Comment: Apparently the comments cannot be modified even thorugh webpage.
On the bright side, somebody has done the computations for us. Check the updated answer.
Comment: It does actually, the number of collisions is dependent on the size of the small body. I will put a reference. Besides it's easily observed with the number of larger impacts we see every 100 years or so, for eg Tunguska event by a large asteroid took place almost a century ago,  while a mass extinction event took place over million years ago and is assumed to be overdue now.
Comment: Good to know about the source, and I remember most of your points from my solar system physics courses, but still the question is about asteroid-asteroid collisions. Exactly finding out the frequency would be a pestering multi-body perturbed orbital equation to simulate, but it would be interesting to know if anyone has worked any sort of figure for the frequency of collisions.
Comment: Yeah, I get it, but, the original question did not specified asteroid-asteroid collision. I'll look into it and see what I can find. But you're right it will  involve simulating multi-body perturbation model, but there must be analytical expressions obtained from statistical analysis. And I think if we assume simple nodal interactions between each orbit then we can use Wetherill modification, to particle in a box model. But since most asteroids lie along the same place there would be some corrections to it. Also, how do you edit a comment through the app?
Comment: Not sure if you can edit comments through the app, which seems weird. Yeah now that I look at the time stamps, your answer was posted after the last edit to the question, so that explains it. I'm guessing the only way to find out the frequency analytically would be to take two asteroids' orbits, and see where they cross and if they ever collide, but to have a general case does seem like a computational nightmare…


Indian rose drink rose name

Question: What is the technical (latin and common) name for the perfumed roses used to make Indian rose drinks? Is there one type our several ? I would like to get a few and plant them in my garden. Thanks.
Comment: In my (far from India) experience, the lassi (or whatever else - works well in lemonade, too) has a bit of rose water (commercial packaged product) added to it. Presumably that then makes your question what types of roses go into rose water (and the additional question of "is "Rose water" == "Rose essence" or not...) I just buy a bottle of rose water every few years and don't worry about it too much. Look for the stuff meant to be food, of course. In seeking roses, you'll want ones with the now out of fashion "smells like a rose" characteristic.
Answer: This site says rose essence can be used for the drink.  Rose essence is made from "centifolia, damascena and gallic (rose variants)"
So, this leads to  Rosa × centifolia,Rosa × damascena, and Rosa gallica
Comment: This page says rose essence is used to make the drink http://secretindianrecipe.com/recipe/gulab-sherbat-rose-drink
Comment: Thank you, I will see off I can find these at my local flower shop. Where on the site is it reference that those are the roses from which the Indian drink I mentioned are made? Thanks.
Comment: I'm a bit blind and couldn't find it. Do you know the Indian name for the rose drink? Also, could you include a picture of the drink to make sure we're talking about the same thing. That would help clarify. Thanks.

Indian rose drink rose name


Has anyone tried Gibson Assembly Optimizations?

Question: Has anyone tried the chew back-anneal in vitro DNA assembly method (known as Gibson Assembly) for difficult sequences, like GC-rich sequences? How big constructs could you efficiently assemble? Did you use the original protocol or some optimizations?
Comment: I've just joined the Gibthon team, so if you need any more specific help let me know.
Answer: I haven't tried Gibson Assembly myself, but I do know the Cambridge iGEM Team in 2010 and 2011 developed a web-based tool - Gibthon - for automatically generating primers for Gibson Assembly.
You could try running your difficult sequences through their tool to see what it suggests for primers.  It apparently gives you a "value for the Gibbs free energy of the worst case secondary structure of the primer."
Comment: Thanks. Yes, I have heard of the Gibthon software, haven't tried it yet. We have been using the IDT predictor of secondary structure of the primers. Might be worth comparing it to the Gibthon tool. It would have been nicer if some optimizations of the reaction conditions make the use of such predictors obsolete. Not to mention that their precision is questionable.
Answer: I also haven't tried it, but theoretically GC-rich sequences will interfere with Gibson assembly. Since unique homology between the ends is key to the assembly process, repetitive sequences which cause non-unique overhangs will increase the possibility of incorrectly ordered assembly. One solution would be to use alternative codons where possible to decrease repetitiveness.
I'm sure all the overlap design tools will try to avoid repetitive overlaps. Prof Jim Hasselhoff at Cambridge Plant Science is a big proponent of Gibson assembly, it was one of his students who wrote Gibthon. If you email him I'm sure he'll give you specific advice.


Making a FaceTime Audio call using AppleScript

Question: I have read through Make a FaceTime call using AppleScript, but the provided solution is for starting a video call. I am wondering if that solution can be adapted to make a FaceTime Audio call (and by extension, maybe even a call via iPhone utilizing Continuity).
Answer: I found it!
I tried many different combinations, such as facetimeaudio://[phonenumber] and facetime://audio/[phonenumber], but nothing worked. I was starting to think that there wasn't a way to do this.
However, today, I decided to take another crack at it with some different combos, and this one works: facetime-audio://[phonenumber].
Comment: I also figured out how to make calls via iPhone to take advantage of the Continuity features. It uses the URL scheme `tel://[phonenumber]`.


Perlin noise terrain: 3 coordinates from one

Question: I am making a game with procedural terrain, like minecraft. I have a perlin noise function which takes one integer and returns a number between zero and one. However, for terrain, I need a single density value from three coordinates: x, y and z. But my noise function only takes one number. Should I take the average of the noise values for x, y and z for a single density value? Or something else?
Answer: The short answer is it depends.
Yes, you can use three Perlin noise functions, average them & use the result. This will map 3 input parameters to a single output noise parameter. But there are some complications.
First, the noise functions should be uniquely seeded, otherwise you'll get some odd results. For instance, if you use the same seed & function for each coord, the coords <1,2,3>,<1,3,2>,<2,1,3>,<2,3,1>,<3,1,2>,<3,2,1> will all have the same values & this can lead to undesirable symmetries & artifacts in the final result.
Second, even if you do use uniquely seeded functions for each coord, taking the average essentially washes out or mutes some of the original signal.
Usually, the preferable solution is to use a higher dimension Perlin noise function. Perlin noise can be defined as an n-dimensional function. If you need a unique output for 3 input parameters, using a 3D Perlin or Simplex noise function will give you what you want without worrying about multiple seeds, muted results & other annoyances.
That being said, if you haven't already done so, read through some of the procedural-generation  & terrain posts. For instance you may discover that you actually want to use 2d noise function to create a height map for the surface & then use an additional technique to carve out caves beneath the surface.
Answer: There are higher-dimensional noise functions available, but if you're stuck with this one, you can always consider using the Cantor Pairing function. It is very easy to implement and can be pre-computed.
See https://en.wikipedia.org/wiki/Pairing_function#Cantor_pairing_function for further details.


Front derailleur won't change to low gear

Question: My front derailleur is stuck in high gear. No matter how I shift the gears the cable would not tighten hence the bike will not change from high to low gear. What is the cause of this? Btw  it is a Shimano Tiagra.
Comment: So you're saying that changes to the left hand gear lever do not make the front derailleur move?  Can you push the cage by hand and see any motion?  Can you pull on any exposed inner cable and effect a movement in the cage?
Comment: The possibilities are 1) broken shifter 2) broken or stuck inner cable 3) frozen derailleur, or 4) maladjustment of cable length or limit screws.  Provide a bit more info and we can focus in on a good relevant answer.
Comment: As far as I know all road front derailleurs are low-normal, which means the cable should loosen when shifting to small ring. Can you move the derailleur cage after you detach the cable?
Answer: Set the shifter to low.
With the shifter at low and the derailleur stuck at high, the cable should feel slack. If it still feels tight, the cable may be jammed or corroded, so replace the cable, or find whatever's crushing the outer cable (if the outer has been crushed you may need to replace it too).
On the body of your front derailleur you should find two limit screws, labelled "H" and "L". If the tip of the "L" screw is making contact, unscrew it (anti-clockwise) to allow the mech to move towards the low position. If the mech doesn't move and you get space at the tip of the screw, one of the mech's pivots is seized.
Comment: 'Outer cable' is usually is referred to as the 'cable housing'
Comment: Manufacturers call it that. Most cyclists use "inner cable" and "outer cable".


Is mainline Bitcoin planning on switching to deterministic wallets?

Question: Deterministic wallets enable reliable backups but the mainline client doesn't use them.  I was told that bitcoind and Bitcoin-QT are planning on switching to deterministic wallets by default, is this correct?  Any idea of when?
Answer: It seems very likely, however it also seems to be a fairly long-term goal with no ETA as of yet: https://github.com/bitcoin/bitcoin/issues/5761


Bass pickup height adjustment

Question: I've recently set up my bass with the help of this youtube video:

I'm really happy with it but one question remains. Fender recommends 2mm space between the underside of the string and the polepiece for the treble- and 2.8mm space for the bass side for J- and P-basses. I can get real close to that adjusting the P-pickup of my Yamaha PJ-bass but adjusting the J-pickup is more difficult because of it's bar-shape. So I'm spot on with the E- and G-strings but the A- and D-strings are too far from the polepieces. That's because I have adjusted the action before so that the undersides of the strings are a certain distance from the 12th fret <code>(E->3.5mm/A->3mm/D->2.5mm/G->2mm)</code>. This results in the A- and D-strings sitting higher at the action than the E- and G-strings. This means I can never be spot-on with my pickup height for the J-pickup because if I raise it some more to be closer to the inner strings I'm too close to the outer strings.
Do I need to loosen the truss rod and reajust the action before taking a look at the pickup height again?
Answer: It is more important to get the distance from strings to fretboard correct than the distance from strings to pickups, so if you have the action setup right I would be content with minor discrepancies from the ideal pickup separation.
There is so much difference between pickups anyway that if it really concerned you you could just buy a different pickup that has a different shape, or individually adjustable pole pieces, and as Carl points out, once you have the electrical signal you can do much more with it anyway.
Comment: Thanks for the answer. I noticed that the way the bass came from the factory both pickups hav a slight slant towards the neck meaning the edges facing the bridge are a bit higher. Does it need to be this way or is it coincidence?
Comment: @arno  Magnetic fields just aren't that precise.  You're going to get far more control of the tone w/ the follower electronics than by microadjustment of the pickup location.
Answer: Most pick-ups are pretty flat, and fingerboards are cambered.This is usually reflected somewhat in the contour of the saddles. So it's going to be a compromise anyway.The figures quoted are more of a starting point than anything exact - some players prefer higher, some lower, action, and each bass,( or guitar) will have its own slight idiosyncracies. Sort out the action to suit your playing, and get the pick-ups close-ish to the strings.If they are too close, you may hear 'wolf-tones', telling that they're - too close!
When you play, if the volume is about the same from each string, then it's adjusted correctly.

Bass pickup height adjustment


Wordpress Multisite Installation Error

Question: I have a Wordpress multisite that I have civicrm installed on.  I did an upgrade to the new version and the database shows that it is the new version.  Problem is that the civi dashboard thinks it has not been upgraded and shows an error.
Answer: I've seen this happen when there's a permission issue on the version-info-cache.json file that prevents the upgrader from properly deleting it.  The file can be found in your CiviCRM "Temporary Files Directory".
If you're not sure where to find your Temporary Files Directory, you can check at Administer menu » System Settings » Directories.  If there's a token (e.g. [civicrm.files]/upload), you can see the value of the token by pressing the "help" icon (see screenshot below).
Try deleting version-info-cache.json manually (e.g. via FTP or CPanel File Manager).  Then visit the Civi System Status Page (Administer menu » Administration Console » System Status) and the issue should clear up.
This file is also auto-deleted every three days - so if this seems like a lot, simply ignore it!

Wordpress Multisite Installation Error


Gap created after Screw modifier

Question: Just a quick question, is it normal for there to be a gap along the surface of a mesh once the screw modifier has been applied?
Answer: There can be gaps but they're not inevitable.

The Angle should be 360° so the edges line up.
The Screw value should be exactly the same value as the object's dimension in the relevant axis.
The highest and the lowest vert should have the same distance from the screw axis.
After applying the modifier, using Remove Doubles with the relevant verts selected and a large enough threshold should kill any small gaps. Without that, a Subsurf Modifier might produce a gap.

Gap created after Screw modifier


jquery draggable +sortable with custom html on drop event?

Question: Change html when drop element in droppable area.
Something like this: http://the-stickman.com/files/jquery/draggable-sortable.html
But when I drop element change placed html.
Other Example: I have 2 lists first draggable list and second droppable list, when i drag element from a first list and i drop this element into a second list, the element will be cloned to the second list
dragging:
test

drop:
test

i want to change this html to
dragging:
test

drop:

test

Comment: Please edit your question. I am sorry but I don't understand what you intend to do and what you expect. What do you want to change?
Answer: Check this DEMO http://jsfiddle.net/yeyene/7fEQs/8/
You can customize your dropped element as you wish.
$(function() {
    $( "#draggable li" ).draggable({
        connectToSortable: "#sortable",
        helper: "clone",
        revert: "invalid"
    });

    $( "#sortable" ).sortable({
        revert: true,
        receive: function(event, ui) {
            var html = [];
            $(this).find('li').each(function() {
                html.push('
'+$(this).html()+'
');
            });
            $(this).find('li').replaceWith(html.join(''));
        }
    });
});

Answer: This is a very basic example but should be applicable for several different cases.
I took the jQuery UI Draggable + Sortable example and besides the .sortable() widget I bound the .droppable() widget to the
 element.
Even though not the smartest way in the drop event of the droppable widget I check the value of a variable to identify the origin of the moved element. (does it come from the sortable list or from one of my draggables?)
If it does come from one of the draggables I change the HTML of it to what I want. Otherwise it remains the same (because you just rearrange the order of the sortable)
HTML

Drag me down

Item 1

Item 2

Item 3

Item 4

Item 5

JS
$(function () {
     var origin = 'sortable';
     $("#sortable").droppable({
         drop: function (event, ui) {
             if (origin === 'draggable') {
                 ui.draggable.html('Look at this new fancy HTML!');
                 console.log(ui.draggable);
                 origin = 'sortable';
             }
         }
     }).sortable({
         revert: true
     });
     $("#draggable").draggable({
         connectToSortable: "#sortable",
         helper: "clone",
         revert: "invalid",
         start: function () {
             origin = 'draggable';
         }
     });

 });

jsfiddle for demonstration
Quite a boring example because the new HTML is static. But let's say you have a custom helper for each draggable and this should become your new HTML.
Therefore you e.g. have stored some HTML fragments in an array and choose the matching entry suitable to the index or what so ever.
This would somehow look like that:
var helpersArr = ['<input type="text" />', '<input type="file" />', '<input type="submit" value="Save" />'];
var helper;
//draggable
helper: function () {
    helper = helpersArr[$(this).index()];
    return helper;
}
//dropppable drop function
ui.draggable.html(helper);

jsfiddle for second example
Pretty sure you could also achieve the same result by avoiding the helper variable and use ui.helper instead but I couldn't figure out how to get the HTML portion of it.
If this doesn't work how you need it, just inform me. Altogether I think you can use my examples as a start for different goals concerning to change the HTML of the dropped element.
Comment: Hi, rather than this `var helpersArr = ['', '', ''];` can you share how to load this from the server/ajax, i.e. making the filled items dynamic?
Answer: I had a similar problem that required a far more elaborate outcome.  My system was dragging from a div on the left that contained other divs with form element names and ids, which dropped into a sortable div on the right that was to become a webform.  Because I needed the div on the right to closely resemble the contents of a form without extra markup, using an unordered list was out of the question unless I wanted to do a bunch of "scrubbing" on the way into the database.  No thanks.  In my example, when I drag from the list on the left, I have to use the id of the dragged element to look up a number of things via ajax, and then place a label, form element, and validation into the list on the left based on the results of that ajax.  For clarity's sake, I removed the ajax from my example.
So, in essence, you're taking two side-by-side divs, doing draggable and sortable with list connection.  The key is that there are callback functions in Sortable that you have to make use of.  The "Receive" callback will fire only when a new element is added to the sortable list.  This is important, because you have to differentiate so your change doesn't occur on sort as well.  You can't solely use "receive" though, because if you try to manipulate the html in that callback, you'll affect the list your dragging from, not the list you're dragging TO.  To keep track of whether it's a list add or a drag, I set a variable called "newlement" in $.data to 1 if its a list add, which I then check in the update callback to see if I should effect the dragged html or not.  In my case, I don't want to do anything to an element that's dragged.
So, the HTML:

First Name

Last Name

And the jQuery:
$( ".master_list div" ).draggable({
    connectToSortable: "#webform_container",
    helper: "clone",
    revert: "invalid"
});

$( "#webform_container" ).sortable({
    revert: true,
    cursor: 'pointer',
    placeholder: "placeholderdiv",
    connectWith: '.master_list',
    start: function() {
            /* Clear the value of newelement at start */
        $(this).data('newelement', 0);
    },
    receive: function(event, ui) {
            /* Get id from function and pass to the update to do stuff with */
        $(this).data('id', ui.item[0].id);
            /* Set value of newelement to 1 only when new element is added to list */
        $(this).data('newelement', 1);
    },
    update: function(event, ui) {
        /* If newelement ==1, this is a new element to the list, transform it */
        if ($(this).data('newelement') == 1) {
            var fieldname = ui.item.text();
            ui.item.html('your new html here');
        }
    }

});
Comment: this is what I am looking for, except I want to load html from the server/db. Can you please share the Ajax, how you're avoiding the scrubbing and appending.
Answer: Check out the documentation on sortable.  You can use the ui element to change the html of the dropped object
http://jqueryui.com/demos/sortable/#event-update
you can also see examples of connected lists here and the events that are fired
http://jqueryui.com/demos/sortable/#connect-lists
The update event is where you would change the html of the element.


Why do turbofans go faster than turboprops?

Question: Can someone explain why turboprops are less effective in terms of thrust than turbofans? But at the same time, why turboprops burn less fuel? For example, the Bombardier Q400/De Havilland Dash 8 has a fuel burn of 2.79L/seat/100km, whilst the 737 MAX 8 with the same number of engines burns 2.93L/seat/100km, but the Bombardier has a max. cruising speed of 360 knots and the Boeing plane can go up to 526-527 knots, even though it's heavier.
Comment: For your second question: [How does propellers' pitch change during the use of reverse thrust in turboprop/propfan propelled planes?](https://aviation.stackexchange.com/q/59249/14897) -- and [others](https://aviation.stackexchange.com/search?q=turboprop+reverse) -- Note: it's advised to [search the site before asking](https://aviation.stackexchange.com/help/how-to-ask).
Comment: Most, if not all, turboprops can put the propellers in beta and generate reverse thrust.
Comment: Because they are attached to faster airplanes?
Answer: To generate a given thrust, a turbofan accelerates less air but faster than a turboprop. This means that turbofans can fly faster. However thermodynamically it is more efficient to accelerate a greater mass of air slower, so turboprops are more efficient and that translates into lower fuel burn.
Answer: It's all dependent upon what operating speeds your aircraft will be in.  Propellers can move a great volume of air at slow speeds but accelerate the gas to a lower exit speed than does a turbojet or a turbofan.  This is the principal reason that a helicopter is the most efficient means of VTOL flight out there for a heavier than air aircraft.  But as speeds increase, the the specific impulse drops and the propeller efficiency drops off with it.  At around 400-500 mph, the specific impulse of a high bypass turbofan becomes superior to the turboprop, as, while it moves less air than a turboprop, it can accelerate the smaller air mass to a much higher exit velocity.  This trend continues through low bypass turbofan engines, turbojets and then ramjets.
And as pointed out turboprops have a beta and reverse pitch range which can produce reverse thrust.
Answer: Turboprops are less fast because of the mechanical constrainsts at the blade tips,efficiency and noise near the speed of sound.
For reverse thrust:yes
related :
How does a turboprop engine keep running during thrust reversal?


Convert xy coordinates to latitude & longitude

Question: Is there an easy way to convert coordinates (TM65) to latitude/longitude using ArcMap (version 10.3.1)?
Comment: Make XY Event Layer tool should do this. http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00170000006z000000
Comment: I'm assuming the coordinates are in a file (like csv or excel)? Do you want the results as coordinates in a file also or as points?
Comment: Yes they are in a csv file, and I want to take away lat/longs in a csv file also
Comment: Have you tried Make XY Event Layer as suggested before?
Comment: Yes, but I could not get it to work. I might try contacting the actually irish grid reference guys, and see if they have an in house converters. Thank you for your help and comments
Comment: @Kelly - Have you succeeded donig that? if so, how?
Answer: First add your coordinate data to ArcMap. You can use Add XY Data or as faith_dur suggested in a comment the Make XY Event Layer tool. Be sure to specify the coordinate system as TM65 with either tool to correctly define the coordinate values of the points.
Depending on how you create them you may need to save the result to a feature class or shapefile for permanence. Once created, open the attribute table. I think your original XY coordinate columns will be there, but if not you can add two new fields (I'd call them TM65X and TM65Y) to recalculate the values. Be aware that if they are there or if you calc them, those are now just attributes and have no relation to the point geometry. If you move a point via editing, they will not update. While you're adding fields, add a lat field and a long field using at least float data type.
Open the dataframe properties, either by double-clicking or right-clicking it in the ToC and go to the Coordinate System tab. Set it to WGS84 (or whatever geographic datum/CRS you want to use to generate your lat/long values). When you Ok out or hit apply, you should get a warning that your point layer doesn't match the dataframe with a button called Transformations on it. You'll need to click the that button and select the appropriate transformation to go from TM65 to whichever CRS you chose. Note there is some discussion at this question regarding transformations from TM65 that may influence your decision.
With that done, to get the coordinate values, right-click a field heading in the attribute table and choose Calculate Geometry. You'll be able to choose the X or Y coordinate of a point at the top as well as choose either the CRS of the data or the dataframe. If calculating the original TM65 coordinates, you'd choose the data. To get the lat/long coordinates, you'd choose dataframe. Calc each of the two or four fields you need. Once that's done, you can export the attribute table back out to a csv and you'll have your coordinate values in both CRSs.
Note that if you have trouble all of these steps are covered at one question or another here, so you should be able to find more info on a particular step/process by searching on terms here.


Cookie restriction mode not working

Question: I'm using magento 1.9 and I'm trying to set up the cookie restriction mode to display the cookie notice. I have everything enabled and appears set up correctly but the cookie notice doesn't display, is there something that I'm missing?
Answer: I feel like this is way better looking and nicer alternative with a lot of customization possibilities.
Just add the script in: System->Configuration->Design->Footer->Miscellaneous HTML
For example:

(But check the link for more customization)

Cookie restriction mode not working


Relevant comments keep disappearing

Question: With regard to this question, what I consider relevant comments by another user keep disappearing by unilateral moderator action - one of mine too (probably by the time anyone checks this, more than one), but mine are not the ones I am as concerned about. The other comments contained at least tangentially relevant links; blog posts and such where others had dealt with the question asked, and shared their point of view. It leaves a bad taste in my mouth, in particular on a site that I hoped would be interested in impartial analysis.
Answer: I wasn't a moderator involved - so I can't directly respond to motivations, but I can address some side issues.
Was this "unilateral moderator action"?
Well, in a way, all comment deletions are performed by one moderator - there is no voting involved, so it could be described that way. However, there was a system-generated flag warning all the moderators that the comments had got out of hand. Further, Sklivvz raised a flag on the question himself - rather than risk an appearance of a conflict of interest - requesting that another moderator clean the comments up.
So, I would argue that, no, it wasn't unilateral, AND that Sklivvz isn't an appropriate target.
@Larian did the honours - he hadn't been involved personally in the conversation -  cleaning up side-conversations including comments posted by three other mods (Sklivvz and @KonradRudolph AND me!)
Could some of the comments have been saved? (Well obviously my pearl of wisdom should have been :-) ) Maybe; I'll leave that to Larian to defend. But Stack Exchange Inc's attitude to comments is pretty clear [a citation would help my argument!]: comments are second-class citizens.

I note there is now a chat room for discussion of the question.
Comment: `a citation would help my argument` -- [Comments are disposable](http://meta.stackexchange.com/a/19757/139866) and [Should we allow unreferenced answers as comments?](http://meta.skeptics.stackexchange.com/a/2606/2703)
Comment: Thanks for taking the time to answer, in a friendly tone. The removed comment(s) I find hard to justify were those by user @DVK who linked in relevant feedback. I meant to read the links in more detail later (as I thought they'd be still there), as at least one of them interested me - a statistician discussing the article in a blog post.
Comment: (ctd.) To remove such a link, whether directly or by asking a fellow moderator (to state "it wasn't me!" If he still initiated deletion, is then also dubious) makes me still question the repeated claimed scientific detachment and interest in a politics-free treatment of this question. Just discovered sceptics; thought it was great if not awesome; lost all respect.
Comment: Also the answers to [Are political comments a problem?](http://meta.skeptics.stackexchange.com/q/2190/2703)
Comment: [What "comments" are not . . .](http://meta.workplace.stackexchange.com/q/72/18412)
Comment: @gnometorule please stop leveling accusations at me. If you have problems with how this site is moderated, contact the community team with the "contact us" link at the footer, but stop accusing me of imaginary plots. It's particularly out of place here :-)
Comment: I'd generally avoid hand-picking comments to keep in such situations, only removing one side of the conversation can be seen as bias, and the comments without context are often problematic anyway. So removing all of them is the right choice here.
Answer:
The other comments contained at least tangentially relevant links

It's policy across all stackexchange sites to not have too many comments.
Too many comments can detract/distract from the questions and answers.
If a link were relevent then perhaps it should be in an answer, not in a comment.
As a (non-moderator) user I occasionally flag comments which (In My Opinion) are excessive or unwarranted in one way or another. A moderator will usually agree with my flag and delete what I flagged.
Although Sklivvze is a moderator he is also a user. As a user he is allowed to do anything other users do (including flagging comments for other moderators to act on).
This site has strict rules for answers: answers must be on-topic (must directly answer the specific question), must be referenced, etc. Answers which don't meet these criteria are deleted. Deleting these answers contributes to making this a high-quality site.
People sometimes post lower-quality answers as comments instead of as an answer: any such comments too ought to be deleted.
The best type of comment (i.e. what comments are meant to be for) are comments which suggest how to improve the question. Any other type of comment may be deleted. Even this type of comment can be deleted, after it has been used to improve the question.
This is a generic answer because I didn't read the deleted comments which you talked about. However, "tangentially relevant links; blog posts and such where others had dealt with the question asked, and shared their point of view" sounds quite off-topic for this site. The only content on this site is meant to be (basically) peer-reviewed evidence, not crowd-sourced opinion -- see How do I know that the information posted in this site is reliable?

Relevant comments keep disappearing


Is it possible to fit a 26" fork to a 29er bike frame

Question: I want to buy a cheap frame and put parts from my old 26" (wheel and fork) and 15" (frame). Is this possible.
Comment: There are a half-dozen different schemes and dimensions for the fittings between fork and frame.  Might fit, might not.  But note that putting a 26" wheel on an 29" frame will lower the cranks closer to the ground and may seriously affect ground clearance.
Comment: at most, buy a 27.5" frame. 26" fork is more likely to be ok (can't promise it, but it might be - depends on the fork of course, if your existing fork is a cheapo just junk the whole thing). 26" into 29" is definitely a bad idea.
Answer: Update: Fixed bad calculation for the BB drop, thanks to @mattnz.
Physically, it may be possible to fit the fork alone. But the resulting bicycle will be dangerous to ride, for at least two reasons.

The wheels with 26" rims vs 29" rims  are at least (622 - 559)/2 = 31.5 mm or 1¼ inch lower, meaning everything will be lower, including the bottom bracket and the pedals in their lowest position. This means you will have much greater chance to scratch the road or trail when pedaling. Even if it won't touch the ground when you ride the straight line, at cornering the whole bike leans, and pedals go even lower. An unexpected pedal-to-ground contact, especially when cornering, can kick the rider out of the saddle.

What size of wheel will you put at the back? If it would be a 29" one, the bike will look very odd, a "reverse mullet" of sorts. Besides the looks, a bigger wheel at the back will increase the steering angle, which in general corresponds to more sensitive steering. The bottom bracket will still become lower, although at lesser extent. The bike will be twitchy to control. If it would be a 26" wheel at the back to match the front wheel, see the lower bottom bracket argument above. Plus, if you have a frame for rim brakes, they won't work because they are designed for a specific diameter of the rim.

Using 26" wheels in a frame designed around 29" ones is really not recommended unless you can run all the numbers yourself for the specific frame and are confident that it will work, and you understand how the resulting bicycle geometry changes affect ride characteristics. As an example, for frames designed around 27.5" wheels, some people did use 26" wheels with them. But then one needed extra wide/high tires to compensate for the rim diameter difference. Wider tires are less likely to fit into the frame/fork without rubbing, so there are limits to this as well.
The difference between 29" and 26" wheel is just too big for this trick to work on regular bicycle frames. Some fatbike frames allow even that, e.g. one of my bikes accepts both wheels with 26"×4.8" and 29"×3", as confirmed by its manufacturer. But that is fairy unusual.
Comment: Height is decreased by half what you say (32mm)  (rim diameter vs radius) Some of this may be regained from plus tires if the 26" rims are wide enough to support them, so could get to less than 20mm lower BB.  That said, I do agree with the premise of the answer that (Apart from "because I wanted" ) its not a good idea .
Comment: @mattnz You're neglecting the fact that the 26" fork is also shorter than the 29" fork the bike was designed for.  So the front of the bike will drop about the full three inch diameter difference, lowering the bottom bracket about half that if a 29" rear wheel is used, or about three quarters of that if a 26" rear wheel is used.
Comment: @CarlBerger Sure, but they are *designed* around that clearance/BB width with both pedaling and steering in mind. Full-suspension bikes have all sorts of protection on downtube and chainring area. Moreover, one generally does not pedal them at full compression, unless one wants to learn why that is a bad idea.
Comment: @mattnz D'oh! My math sucks. Thanks for the correction, I will include it now into the answer.
Comment: Good point.  Axle to crown of fork needs checking even if not changing wheel size (though usually 'close enough' for same wheel size).
Comment: Well, normal bikes differ in ground clearancce already more than ~1", which is the expected difference from a 26" wheel and a 28"wheel. And imagine a full-suspension bike .. ground clearance changes by 6" depending on riding state ..
Answer: Firsts-off:
On a practical side for reusing old components on a new frame, you need to make sure all the standards match:

Fork steering tube
bottom bracket width / size /desing
rear wheel dropout (width/design)
seat tube dia (and seat tube length)
cable endpoints,
front derailleur mount
rear disk brake mount (or Canti/Vbrake -Sockets)
mounts for lights / mudgard / bike stand etc..

Next - these standards change over time, especially in the last 10..12 years there was quite a development and fragmentation of standards. If you have old components, and you manage to find a new, shiny, good frame that accomodates all those old standards, then you're stuck with them and it will be hard to find good new components that fit those old standards.
Last not least - economic aspects:
usually buying all the components of a bike will be a lot more expensive than buying the whole bike (in my experience it was factor of at least 2x).
Side Note on riding characteristics:
Using a shorter fork is not only lowering the bike, it's also lowering the front more than the rear. This rotates the bike frame, and increases the steering angle by ~approx 1.5deg per inch shorter fork.
That in turn reduces the steering offset & has an effect on bike stability.
How much? will it still work?
that depends largely on how the bike was in the first place, and how much stability decrease you're comfortable with.  In an extreme case you could get to an unstable bike: one where you wouldn't be able to take the hands of the handlebar.
On the other side: the difference in fork length beteween 26" and 29" bikes is approx 1 inch, and eg in an MTB suspension forks travel a lot more without problem.
Bottom line:
it would be significant work with ~uncertain outcome, and likely not saving much money


Problem with camera view

Question: My camera view is not right. i'm new in blender so i dunno how to fix it, i have tried everything but can make it right the camera view on the right seems to have like a lens that makes it look that way, Thanks
Answer: there are two settings viewport focal length (35, in your case) and camera focal length (30.72 in your case), 35 would be default.
on your picture i cant really see a problem, you just have zoomed out while being inside the camera so you se the fisheye-distortion of your camera around the real sensor area. if thats the problem just zoom in.
Your render should look good with 30.72 focal length. If you want ist exactly as in Viewport put it to 35 in Camera-Lens menu.
but maybe i'm missing something?
Greetings AM

Problem with camera view