Sanitizing with a spray bottle of StarSan

Question: Can I sanitize all my large fermentation equipment (buckets, lids, tubes...) by spraying it down with a spray bottle of starsan? Just wondering, because so far I have just been filling the 5+ gallon bucket with starsan solution and sanitizing everything in the bucket. The problem with this is that I feel like it wastes so much starsan, and that stuff isn't exactly cheap.
Answer: You can probably achieve adequate sanitation with some very thorough spraying, but the spray from a bottle is not exactly uniform. And I'm not sure how you'd get the inside of tubing effectively besides filling it and sloshing it around, which is certainly an option.
You don't need to dispose of Star-San after using it. You can keep it around for a while, and it will remain effective so long as the pH stays low. Additionally, if you mix it with distilled water, it will last for quite a long time. Months, at least.
You might also find a wallpaper tray to be convenient for sanitizing long items (tubes, canes, spoons, &c.) in a minimal amount of Star-San.
Comment: You don't need to mix 5 gallons of StarSan for a 5 gallon fermenter. When I mix it fresh I make about a gallon, seal up the fermenter and shake and slosh to get coverage. I also spread it by hand and use a spray bottle on individual components as necessary. I store the leftovers in old LME jugs.
Comment: I've never had an infected batch. Star San only requires wet contact with the surface for a few minutes, not extended soaking, so it's not necessary to fill the fermenter. While it's reasonable to be thorough with sanitation, there's no need to be paranoid. My method is to clean equipment ASAP after use, dry thoroughly, and rinse briefly before using again (and before sanitizing). And remember that most undesirable microbes aren't able to compete with the relatively huge colony of brewer's yeast that you pitch.
Comment: Thank you for the suggestion on the wallpaper tray. I understand that it is possible to reuse star-san solution, but I live in a small condo and have no area to be constantly storing a 5+ gallon of sanitizer, when I have the space I will start doing this.
Comment: Starsan is still effective if the pH is under pH 3.5
Comment: @Jim, have you ever had any problems with bacteria with this method? How many times have you done it? I would love to try it but am always afraid of losing a 5 gallon batch due to poor sanitization.
Comment: I'll second @GalapagosJim's statement that 1 gallon is plenty for a 5 gallon batch. I slosh it around in the fermenter and then pour it into a bowl to soak airlocks, hoses, etc.
Answer: I always have a spray bottle of Star San made up. It's definitely adequate for small items and touch-ups, but I slosh around a gallon of Star San in my carboys since it's easier.
The other thing I do to sanitize some things is to wet a paper towel and then wipe the surface.
The only thing that matters is that you wet all the surfaces and then give it a minute or so to do its thing.
I regularly make very small batches of Star San solution. I use a syringe (not to be confused with a hypodermic needle) to measure out a few mL of concentrate. At this rate my bottle of Star San concentrate is going to last for years.


Merging tags or creating synonyms

Question: Should we start merging similar tags (like events and civievent), or keep all of the similar versions and set them up as synonyms with the "main" tag?
Answer: I've done some testing and reading, and I think merge is preferred for a couple of use cases. It cleans up the multiple tags and creates a synonym for them at the same time to prevent the bad tag from coming back (singular vs plural, misspelling, etc). So if there are tags that we think may need to be broken back up in the future, we would create a synonym but not merge them.
Answer: Just guessing, but maybe the advantage of synonyms is that if we delete e.g. the "event" tag, someone new will just come along and create it again.
Answer: I too favour creating synonyms of tags as a way of reducing tedious unnecessary work. Thanks for raising the topic Nicholai.

Merging tags or creating synonyms


Why date/time automatic adjustment didn't work?

Question: Recently I went to Italy and bought a pre-paid TIM chip to use while there, because it was much cheaper than the ridiculously high prices of Rogers' roaming.
However, something quite puzzling happened. Whenever I changed batteries (I don't recharge my phone, I change battery to a full one and put the other one to recharge on an external charger) I would lose my date/time, it would reset to 1/Jan/2000. Manually setting it worked, but it was a bit annoying.
I didn't understand why the "Automatic (Use network-provided values)" setting didn't work. I was assuming that the phone would use NTP, and once being able to resolve DNS it should adjust the date/time, but it never did.
Doing some googling I found about NITZ, which apparently Rogers uses but Italian's TIM doesn't. My questions are:

is this the reason why automatic updates didn't work?
is there a way of changing these configurations? (use NTP instead of NITZ for example, or some other configuration that would make the automatic update work, other than installing an app)
Answer:
Most likely.
If your phone is rooted, you can install an app that will sync the clock using NTP. (Just search for NTP on Google Play: there are many such apps.)
Answer: BAT500 is capacitor which hold charge when battery is removed. If capacitor discharge fast then time change to 1 June 2000. I am not sure that problem is with capacitor. You can check for it.
When you connect to network. it take local time zone. So I do not think you need to change NTP protocol.


In a ranking system, what value is conventional for scores/set/points quotient when the divisor is 0?

Question: For instance, in volleyball they use set quotient or points quotient as tie-breakers. They are simply the result of sets/points won divided by sets/points lost. But what if sets/points lost is 0? What is the conventional value that is used?
Comment: If a team has conceded no points a tie break would not be necessary.
Comment: @dly yes it would be necessary when comparing teams with no lost points
Comment: Then please provide an example where you would need it.
Comment: @dly let's say we have a ranking system with wins > score quotient. If team 1 and team 2 both have won the same number of games they're tied, so we need to calculate the score quotient. But let's say the have no score against in any of their games, only score for. My question is then, how do you calculate the score quotient when the divisor is `0`? The post is not about deciding how the tie-breaker is resolved, but how a quotient is usually calculated in a ranking system when the divisor is 0.
Comment: If you have multiple pools that need to crossover according to a rank, or teams that need to be seeded for the next round, having multiple unbeaten teams or teams that have not conceded points.
Answer: In volleyball at least, this is shown as "Max" and means the team wins the tie-breaker over any other tied teams. For example, see Pool D of the FIVB Women's World Championship 2018: Serbia won 15 sets and lost none, giving them a sets ratio of "Max".
Aside: in the very common case of a full round-robin, any team with a set ratio of "Max" is always going to have more wins than any other team; the team with a set ratio of "Max" must have won all its matches, so every other team must have lost a match - therefore the tie-breaker won't be used anyway. In some odd cases where you don't play a full round-robin, the tie-breaker might be relevant.
Answer: In the unlikely event two or more teams actually conceded no points there is no mathematical solution. The quotient will not be calculated, simply because it's not possible. The team(s) involved will just be ranked highest of the tied teams.
Quotients involving dividing by zero:

One team = this team will be ranked higher than the other tied teams; it "wins" the tie breaker
Two or more = The number of scored points will be used as a tie breaker between those teams
If there's still a tie it will depend on the league how to break it
(often only the matches between the teams involved will be taken into account to create a new mini table)


How can you prevent loss of or bad posture during drumming?

Question: As an IT technician I am well aware of the problems with posture and the injuries as a result of such problems at work... so I was thinking can the same principles be applied to drumming to prevent strain on the back and legs? if so how can this be implemented?
Answer: For the back problems, the easiest solution is breathing exercises. It has the indirect effect of making you sit straighter that would otherwise make proper breathing harder. It also gives you a better view over your body instead of burying your head into the snare which happens naturally as you wear off especially during practice.
I don't know your level but the most common beginner error is the wrong adjustment of the snare drum height and leaving the left hand rest on the knee. The proper way of doing it is to get a comfortable height such that you can perform a rim shot with arm making approx. 5-10 degrees below the exact horizontal posture. That extra angle provides some space for finger playing supported by wrist action if required without raising hand.
For the drum chair, over the years I've come to believe that the crucial part is the blood-flow and torso balance and it doesn't have any perfect spot. It differs from individual to individual. But !
If you sit too high then you need to make sure that you use a proper drum stool such that there is no tendency to block the blood flow by the edge of the stool. Also you need to make sure that you are not falling forward. For example, if your are playing the kick heel up, your feet would be busy playing instead of supporting you. For heel-down it limits your foot action as your feet become pivoted at the heel and it is one of the worse things you can do to your muscles.
If you sit low, then you should be more or less sit no lower than the point where your knees point to the toms. It is bad for two main reasons, you need to raise your whole leg up for heel up action and otherwise your lower leg front muscles (don't know their name) start to burn really fast and it becomes similar to the mouse holding hand suffering from RSI. The other problem is simple making crunches everytime you reach for the cymbals or anything that is not within reach immediately.
Comment: When taking piano lessons my teacher had me sit with hips slightly above the knees.  This helps with blood flow and as well as posture.  I'm not a drummer though...
Comment: Thanks for this answer I never knew that how I was playing reflects almost all of the "donts" expressed in this I play heel down and I have a double kick pedal topping 300 bpm in some songs that I play I dare say I should improve my posture this will help me a lot thanks again :)
Comment: @NathanTaylor My pleasure.


Custom data source without options - Sprout Forms

Question: Is it possible to create a custom data source that does not include end user options? I have tried not including the getOptionsHtml(), returning null, returning an empty string, and just return and the all fail.
Comment: Just to be specific, I believe this question is about Sprout Forms for Craft 2. The getOptionsHtml method returns null by default and should display no options if you don't override it or return null yourself.  What specific failure message are you getting?
Answer: A Custom Data Source does not require any settings. If desired, you could create a Data Source that only had a title and did whatever logic and queries that you wanted behind the scenes.
In Craft 2, getOptionsHtml returns null by default and shouldn't need to be set to anything in your Custom Data Source if that is desired:
public function getOptionsHtml()
{
    return null;
}

In Craft 3, the default is to not display any settings also:
public function getSettingsHtml()
{
    return null;
}


Should I give user some time to free play with the environment first before test tasks during the usability testing?

Question: Since we are testing a website with complex structure (navigation) and lots of terminology, we just wondering if we can introduce the background and give user about 5 mins to free clicks the system to get familiar with the content. Any good suggestion?
Answer: EXPECTANCY TESTING or FREE EXPLORATORY TESTING:
Generally, we do "Expectancy Testing" to understand what is the expectation of the user. As the name implies, the goal of this testing is understanding what users are expecting from the application.
Free Exploratory Testing: As the name implies, this allows the user to explore the app for initial few minutes to understand the content, branding, navigation, performance, etc.
You can read more @ http://salzertechnologies.com/usability-testing/
Answer: I would say it depends on what you are expecting to learn from doing this. What are you going to learn from watching someone blindly messing about with your solution for 5 minutes?
A much better technique for testing complex structure and terminology, is running simple card sorts. Do you know how to run a card sort? Do you know there are two different types of card sort?
https://www.usability.gov/how-to-and-tools/methods/card-sorting.html

Knowing how your users group information can help you:

Build the structure for your website
Decide what to put on the homepage
Label categories and navigation

Open and Closed Card Sorting
Depending on your needs, you may choose to do an open or closed card
  sort. They differ as follows:
Open Card Sort: Participants are asked to organise topics from content within your website into groups that make sense to them and
  then name each group they created in a way that they feel accurately
  describes the content. Use an open card sort to learn how users group
  content and the terms or labels they give each category.
Closed Card Sort: Participants are asked to sort topics from content within your website into pre-defined categories. A closed card
  sort works best when you are working with a pre-defined set of
  categories, and you want to learn how users sort content items into
  each category.

In summary, you must always have a clear objective about what you want to learn from your testing.
Answer: Generally, there would be some cost involved when you are engaging with the users. Why let go of the time you have with users for free?
I would recommend going for an exploratory testing as well. Everything the user does is a data point for you. The initial impact of your design on the user is also a crucial aspect of evaluation. I would make sure I am recording everything the user is doing. There will not be free time to play with.
I will let the users roam around for exploratory testing, but I would also request them to talk aloud to let me know what they are thinking. What they are trying to achieve when they click on a navigation label, or what they find confusing etc. I may not start my targeted tests with workflows, but I will make a note of every observation or comment a user is willing to give.
The time you are awarding for free to play actually offers some data points which will be lost when you begin with more standard test runs. Something like the initial impact of your color palette, thoughts on navigation and presumptions of the users, will be captured in the first few minutes. I would not want to miss out on that opportunity.


Would you tell me the difference in meaning 'wanna be starting something.' and 'wanna start something'?

Question: I love Michael Jackson.
I know the song titled 'wanna be starting something'
But I don't know the difference between  in meaning 'wanna be starting something.' and 'wanna start something'?
Could you please tell me the difference?
Comment: It's a valid question, but as many people here have said, don't look to songs for correct or standard grammar.  Lyrics are usually written to sound good or fit the beat of the song, not to be strictly correct.
Answer: As in any language, the English used in song lyrics often has a metaphorical or cultural subtext that's more important than the pure dictionary definition.  While "wanna" is vernacular for "want to", "to start something" is an slang expression that means to "cause trouble" -- to start a fight, incite a riot, whip up a protest, etc.
In the context of the song, Michael Jackson indirectly refers to the many ways the press and the media had been trying to "start something" with him, rather than just letting him be, i.e. they created rumors about his personal life, cast aspersions on his family, whatever of his they could use to make money.
To get back to your question, "want to start something" has the same meaning as "want to be starting something" -- however, you should not mistake the "to be -ing" form as a common English expression.  This sentence pattern is vernacular primarily used by a particular ethnic group, and while it's probably OK to say it, you should avoid it unless you fully understand its nuance.
There's a fine line between imitation and mockery and, in the wrong environment, you might start something you didn't intend.
Comment: Well-put.  I suspect that the use of "be *gerund*" in the song is a feature of Black English (or African-American Vernacular English, or whatever you want to call it) but I wouldn't dare say for sure.
Answer: wanna is the abbreviated form of 'want to' (used informally)
As per Google,
wanna
ˈwɒnə/
informal
contraction

want to; want a.
"you wanna know how low I've stooped?"

Coming to the sentences in questions, first let me replace the unabbreviated form:

1.Want to be starting something.
    2.Want to start something

Basically speaking both the sentence formation is correct grammatically.
Second sentence is the most common form and doesn't need explanation. It is verb + infinitive form.
Checkout the definition of 'want ' from dictionary.com:

to wish, need, crave, demand, or desire(often followed by an infinitive):
I want to see you. She wants to be notified.

The first sentence is also grammatically correct. It is of the form to be (verb+ing) form:
From the website phrasemix.com I have got the following definition and example:
to be (doing something)
Some sentence structures require you to use an infinitive ("to" + a verb). For example:
I want to leave.
She told me to call her.

When you need to use an infinitive, but you also want to talk about an ongoing action, use the form "to be ___ing"):
I told you to be waiting for me when I arrived.
On a day like this, I don't want to be sitting in a dark office. I want to be laying out in the sun.

Hope this explains it.
Comment: The dictionary is correct; however you completely miss the cultural context.  I would not advise saying, "You wanna be starting something?" unless you fully understood that the *actual* meaning is nothing friendly, like you're suggesting a nice game of chess. Please see my answer for more details.


can I use XML for AJAX in a website created using HTML5

Question: I am new to web programming and just started learning XML and AJAX. I am creating a social gaming website for my college project. I am confused at the point of using XML for AJAX in HTML5. As XHTML is replaced by HTML5 so is it ok to use XML or i should choose JSON (i know nothing about JSON but it is what I found in answers on web to the question related to choice between JSON and XML). My preference is XML because it is in my syllabus but I want to make sure that XML and HTML5 will not conflict.
Comment: this post is rather hard to read (wall of text). Would you mind [edit]ing it into a better shape?
Comment: Did you ever check what AJAX is an acronym for? The XHR API? The markup language won't affect the code, and if you control both ends of the client server relationship then code with what you are happy with for now.
Comment: You can use any kind of serialized data, XML, JSON, CSV, INI. JSON seems to be standard de facto this days, since it's much more readable and native to JavaScript.
Answer: You can encode the data sent to the server in any format you want and not interfere with the web page's standards.
The idiomatic thing to do is to just use JSON these days, but that is up to you.
It's also important to note that if you use a non HTML5 tag, the police aren't going to show up at your door and, unless your professor validates your site using a tool, he probably won't notice and it will render just fine.
Certain things in your page like
 being more HTML5 compatible than
 will break XML compatibility, if that's what your asking. But the standard still leaves a clause allowing full XML compatibility in order to allow any page to comply with XML, AFAIK.  Though, from the discussion in that thread, this is explicitly for backwards compatibility purposes with the older HTML standards.
Comment: shall i go deeper in XML before learning and starting use of AJAX or just a basic knowledge of XML schema, DTD etc will give me some base to dive into AJAX
Comment: I should note that I think the term "XMLHttpRequest" was invented at a time when people thought XML was going to be the world's permanent, universal data-as-text storage format. The truth is, AJAX usually has little to do with XML. In modern days, HTML doesn't even have much to do with XML. While the basics of how XML works are useful to know, you do not need to understand the internals of DTD's, schemas, XSLT...and other stuff that a lot of programmers tend not to get so involved with.
Comment: "_DTD's, schemas_"

To reinforce your point, programmers didn't even define these when using XML years ago.  They can be helpful for public APIs (things like XAML), but are relatively useless for a 1-off transport situation


Visibility of vertices in polyhedra

Question: Suppose $P$ is a closed polyhedron in space (i.e. a union of polygons which is homeomorphic to $S^2$) and $X$ is an interior point of $P$. Is it true that $X$ can see at least one vertex of $P$? More precisely, does the entire open segment between $X$ and some other vertex lie in the interior of $P$?
Answer: There are many points in the interior of this polyhedron, constructed (independently) by
Raimund Seidel and Bill Thurston, that see no vertices.
Interior regions are cubical spaces with "beams" from the indentations passing above
and below, left and right, fore and aft. Standing in one of these cubical cells,
you are surrounded by these beams and can see little else.

Figure from: Discrete and Computational Geometry. (Book link).

The indentations visible are not holes, in that they do not go all the way through, but rather stop just short of penetrating to the other side. So the three back faces of the
surrounding cube—obscured in this view—are in fact square faces
of the cube. Thus $P$ is indeed
homeomorphic to a sphere.
To follow Tony Huynh's point: This polyhedron $P$ cannot be tetrahedralized, i.e.,
it cannot be partitioned into tetrahedra all of whose corners are vertices of $P$.
Comment: @BenoîtKloeckner: That polyhedron is homeomorphic to a sphere. Those indentations do not go all the way through, but rather stop just short of penetrating to the other side. Admittedly, that is not obvious from the figure.
Comment: I get it, nice!
Comment: This is an interesting example but does not exactly answers the question, as the polyhedron is assumed to be homeomorphic to the sphere.
Comment: Tried to clarify this point...
Answer: I have a simpler example and I see that its idea is similar to the above one.

Cut the vertices of a cube to form 8 small triangles and suppose the triangles are rigid but the faces are not. Then rotate the triangles, 4 of them clockwise and the rest counter-clockwise, in an alternating manner.

The images are drawn using Geogebra 3D.
Comment: Nice animation!
Answer: Note that the answer is yes in 2 dimensions, since any polygon can be triangulated (without adding additional vertices).  Thus, every point in the interior sees at least 3 vertices of $P$.
One can attempt to do the same thing in 3 dimensions, but somewhat surprisingly there exist polyhedra that cannot be decomposed into tetrahedra (without adding additional vertices).  See here, where they show that the problem of deciding if a 3-dimensional polyhedra can be decomposed into tetrahedra is NP-complete.  The references in that paper might be helpful.
Comment: So, by taking a slice through the point, every point in the interior sees points in the $n-2$-skeleton.
Answer: Here's an orthogonal variation on Ali Khezeli's example,
which T.S. Michael calls1
the octoplex.
The point at the very center of the polyhedron is not visible to any vertex.

(Figure by Emmely Rogers.)

1Michael, T.S. How to Guard an Art Gallery and other Discrete Mathematical Adventures. Baltimore: Johns Hopkins U Press, 2009.
  (JHU book link.)
Answer: It turns that given any convex compact nonplanar $X\subseteq\mathbb{R}^3$ its boundary ${\partial}X$  can be approximated arbitrarily closely (simultaneously in shape and surface area) by a polyhedron $P$ homeomorphic to $S^2$ whose set $N_P$ of points not visible from any of $P$ 's vertices has a boundary that likewise approximates $P$ and ${\partial}X$ in the sense that every point of ${\partial}N_P$ is within $\epsilon$ of some point of ${\partial}X$ and vice versa.

Visibility of vertices in polyhedra


Need Anchors for Pre-cast Concrete Panel with Insulation Inside

Question: I am looking for a solution for mounting a shelf that holds a pressure sprayer to precast Concrete panel with a Foam core insulation sandwiched in the middle.   total weight to support is 300 pounds, The shelf has 6 holes to mount with located in 2 rows of 3. The panel is  8 inch total (3 inches then 2-inch foam panel then 3 inches). ( diameter of holes in Shelf is 1/2 inch so I think 3/8 inch anchors are appropriate.  If anyone could send a link to a product that would be great.   Engineering data / Submittal type info would be very helpful as well.   I need to validate that the ANchors are appropriate for precast concrete.  Thanks in advance!
Comment: A diagram is needed.
Comment: The biggest concern is vibration from the pump. Is it a standard three cylinder pump that runs about 2500 psi or so? The do-it-once solution is to bore six holes right through, then bog in six steel compression tubes that are about 1/8 shorter than the wall thickness, then hang a 1/4 backing plate and through bolt the thing. Don't underestimate what vibration can do to the mounts. How many thousand hours/yr does the pump run?
Comment: Thank you for this information,   I never thought of it this way,    So currently the Shelf does have 6 holes to mount thru,  I spec'd out  Screw Anchors that are 3 inches long,   We cannot go all the way to the exterior and mount a bracket like you suggested, but that is a great idea.    That said, these anchors are rated to almost 7000 LB  for tension and shear forces- each when fixed to a 3-inch concrete panel.
Answer: This is a situation that should be reviewed by a structural engineer. More about preventing damage to the panel then about support of the item.
For anchor information, check out Simpson Mechanical Anchors. The Titen HD is a common choice
Comment: Thank you for the link and suggesting  that an engineer review,  that's what we ended up doing,  and the link has very useful information about the options for selecting anchors.


My prisoners wont move from the holding to cell to the actual cell

Question: I have a cell block with 25 cells but none of my prisoners will move there from the holding cell. I have working power and water beds and toilets they are separate from each other it has all the requirements why wont it work? Any ideas?
Answer: This behavior is caused by cell quality : some prisoners do not diserve any cell based on cell quality and their behavior.
When you go to "Policy" tab you can choose to enable or disable the cell quality ratings.

This is the description on hoover :

Use Cell Quality
If enabled, Prisoners will only be assigned to a cell of a quality they deserve, based on their behavior. Poorly behaved prisoners will never be assigned to a high quality cell, even if there are no other cells available.
  If disabled, prisoners will be assigned to any cell regardless of quality, but but prisoners in cells of lower quality than average will be more resentful. Prisoners will still be upgraded to higher quality cells if they behave well.

You have a few solutions :

Disable the Cells Quality Ratings
Build new low quality cells
Downgrade you cells quality (remove windows, TV, bookshelves, chairs...)
Wait until you prisoners behave better and deserve a better room (bad idea, they will fight a lot if they are unhappy in an holding cell).
Answer: If you actually have defined cells, guards will eventually move prisoners into them from the holding cell. If this isn't happening, you may not have enough guards.
If you have free guards and they're still not moving, you can select each prisoner and manually order him into a cell.
Comment: I don't think you can manually order prisoners to move around, at least I can't :) Selecting a prisoner and right-clicking to move them somewhere else does nothing. How do you manage it?
Comment: @Tony You can't manually order prisoners around like with staff but ordering them into a different, unocupied, valid cell will assign them that cell instead.
Answer: Cancelling the holding cell room designation will force the prisoners out of the holding cell and allocate them a free cell each.
Once you have more prisoners arriving than you have cells for you can mark the room as a holding cell again.
Answer: In newer versions, if the prisoner isn't entitled to a room level close to your available rooms, they won't be transferred.
Basically, if you have all high-level (luxurious) cells, your new transfers won't be allowed into them.
Make sure you have some lower-level cells for your transfers until they've had enough good behavior (days without incident) to be allowed into your nicer cells.


Why does tachyon arise in bosonic string theory?

Question:
I am looking for precise mathematical and physical reasons which cause the presence of tachyon in bosonic string theory(specially closed bosonic string theory). Has it to do with the specific form of the conformal field theory of free bosons?
In particular suppose one makes use of a conformal field theory of central charge 26 but different from the conformal field theory of 26 free bosons to formulate a string theory without local worldsheet supersymmetry. Will the tachyon problem still persist?
Comment: For 1.1 : The zero mode of the set of harmonic oscillators (the string excitation) gives a negative energy for each dimension. So the ground state has a negative energy (if the "classical" center-of-mass momentum is zero) and a negative squared mass - $m^2 \sim (2 - D)$ - while $D=26$ for the coherence of the theory (there are $D-2$ excited states at first level, so it it a representation of $SO(D-2)$ which must be massless (the mass of the first level is $m^2 \sim (26 - D)$
Answer: The mass spectrum of closed strings in the bosonic theory is given by $m=\sqrt{N+\tilde N-2}$ (where $N$, $\tilde N$ are non-negative integers or half-integers), which clearly gives you ten imaginary-mass particles, e.g. at the ground state where $N=\tilde N=0$ etc.
The same problem would've held true with the RNS superstring, whose mass spectrum is $m=\sqrt{N+\tilde N - A}$ ($A=0$ in the RR sector,  $A=1$ in the N-SN-S sector, and $A=\frac{1}{2} $ in the RN-S, N-SR sectors) -- but it turns out that the theory needs a GSO projection to remain consistent (see Ron Maimon's comments for an explanation), which also eliminates the tachyons.
Comment: But the theory is inconsistent without GSO projection. The easiest argument is Witten's--- the theory has a gravitino, so it must be space-time supersymmetric, and therefore have no tachyon and come in equal number of bosonic and fermionic particles at each level. The GSO projection is really necessary, it is interpreted as summing over spin structures on the worldsheet, which means certain of the naive modes don't contribute.
Comment: Oh, but then you shouldn't say "it's a misconception that ..." because then people think you are under the impression that RNS strings exist as theories. Ok, no worries, it's just miscommunication.
Comment: With other projections, one obtains the so-called type 0A and type 0B string theories. These have tachyons as their ground state and are non-supersymmetric. This paper (http://arxiv.org/abs/hep-th/0111212) argues that the end-point of tachyon condensation is the supersymmetric type II string. Tachyonic theories are not necessarily inconsistent -- they are unstable and the end-point of their decays, if one can determine them, are stable. Classic examples are the open-string tachyons discussed by Sen (http://arxiv.org/abs/hep-th/9805170).


Light-Particle Wave Duality

Question: There is a lot of reading to do on this to fully understand it, but without doing that reading is there a short explanation as to why and how light behaves as a wave and a particle?
Comment: See here : http://www.youtube.com/watch?v=uK2eFv7ne_Q
Answer: The interference  patterns of light show the wave nature of light.

Optical interference between two point sources for different wavelengths and source separations

The photoelectric effect shows the particle nature of light, because light hits an electron and transfers its energy to the electron.
This link gives an clear explanation and can be a start in understanding the reason light is also a particle, the photon:
Answer: Basically, it depends on the phenomena you're considering. If you're considering diffraction or reflection or interference patterns, it makes more sense to talk of light as a wave. However, since the early 1900's some physicists, among them is Einstein, who proposed that certain behaviours of light, as for example the photoelectric effect, could only be explained if light behaved like particles.
Some years later Louis De Broglie proposed that the particle-wave duality is not exclusive of light, but is present in other subatomic particles, like electrons.
You can have more information in here https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality
and here
http://hyperphysics.phy-astr.gsu.edu/hbase/mod1.html
Answer: Basically photons behave as particles or as waves (deppending on what experiment you are doing) because it's a quantum property. I have not seen further explanation. As long as I know, we have not found "why" particle-wave duality exists.

Light-Particle Wave Duality


What are the design trade-offs in the different rocket engine cycles for liquid propulsion systems

Question: Liquid propelled Rocket engines work on various cycles such as pressure-fed, pump-fed(gas generator,staged combustion, expander, etc) and these have various design trade-offs between complexity, reliability, operational simplicity, development cost(?) etc. What are the various trade-offs between these cycles?
Comment: Which textbook are you using? Which cycles are you considering Carnot, Brayton? etc
Comment: I think I'm not working on thermodynamic cycles but a different class of rocket engine cycles, as described in the comments. This question maybe more relevant to space exploration stack. I'm not sure
Answer: Disclaimer: I am not professional rocket scientist, information is primarily gathered through internet. This answer is provided with NO warranty.
This answer mainly focuses on liquid fuel engines.
Pressure-fed
Very simple design that does not have pumps. Can be easily started. Chamber pressure (and thus the specific impulse) is very limited compared to other cycles. Mainly used in upper stages as low chamber pressure makes operation in atmosphere difficult.
Expander cycle
Simple design that uses cryogenic propellant to drive the pump (and cool the engine). Chamber pressure is similarly limited, also commonly used in upper stages.
Gas-generator cycle
More mechanically complex than the previously mentioned cycles, as it uses a pre-burner to drive the pump.

There are several advantages to the gas-generator cycle over its counterpart, the staged combustion cycle. The gas generator turbine does not need to deal with the counter pressure of injecting the exhaust into the combustion chamber. This simplifies plumbing and turbine design, and results in a less expensive and lighter engine. - Wikipedia

Chamber pressure is not as limited as in the previously mentioned cycles. It can be (and often is) used in first stage, as the low complexity makes developing larger engine easier.
Oxidizer-rich staged combustion
A more advanced design. staged combustion allows greater chamber pressure and higher specific impulse, at the cost of heavier and more complex engine. This cycle is usually used by LOX/Kerosene engines, as the counterpart - Fuel-rich staged combustion cannot be used in LOX/Kerosene engines, due to extreme coking problem. Oxidizer-rich environment  proves to be extremely difficult to handle. Russia developed alloy materials to withstand the high-temperature and oxidizing environment.
Fuel-rich staged combustion
Similar to oxidizer-rich staged combustion, this cycle is mainly used by LOX/LH2 engines (and any other engine that does not have coking problem and wants high specific impulse). I guess the fuel-rich environment is easier to handle than the oxidizer-rich one.
Full-flow staged combustion
Extremely complex design that has the greatest specific impulse and mechanical complexity. The only built examples are RD-270 and Raptor.
Conclusion
Complexities of engine cycles are usually positively correlated to development costs. Reliability depends on the exact design and technology of the engine (e.g. redundancy)
Reference

Encyclopedia Astronautica http://www.astronautix.com/
The English Wikipedia
Comment: A very detailed answer. Thank you. However, I'm looking for a more technical answer, but I fear this isn't the right platform perhaps for such a question.
Answer: The question is somewhat vague, and so it is unclear whether you're asking about types/ categories of engines, or the actual cycle types. In general...
Solid fuel rocket engines
Pros:
- Very simple and very reliable (no moving parts)
- High thrust
- Fuel is relatively safe for ground handling (often is just acrylic)
Cons:
- Once they're lit... they're. No cutoff mechanism aside from burning through all the propellant
- Because of that (^), can be relatively inaccurate in terms of trajectory
- Typically non-reusable, but depends on housing material and characteristics
- Low ISP
- Large and heavy

Liquid/ Bi-propellant/ Tri-propellant Engines
Pros:
- Moderate ISP
- Moderate/ High thrust
- Can be toggled on/ off
- Because of (^) can be used repeatedly
Cons:
- Much more complicated
- Much less reliable (many, many moving parts)
- Fuel (and overall system) is typically dangerous for personnel. Hydrazine a common liquid propellant is extremely toxic
- Requires 2 forms of media -- an oxidizer and a propellant
- Large and heavy

Electric Propulsion
Pros:
- Extremely high ISP
- Designed for extremely long lifespans (and thus, highly reliable)
- Much smaller form-factor/ weight compared to liquid and solid engines
- Typically few to no moving parts
- Over long periods of time, can eventually reach velocities much much greater than that of the other forms of propulsion
Cons:
- Low thrust
- Because of (^) cannot be used for launch -- only in-space maneuvering
- Depending on the type, can be costly and complicated -- but this isn't always the case (such as with Phase Four's RF thruster)
Comment: Thanks for taking your time out to answer, but I'm sorry that I had forgotten to specify that this was about the engine cycles involved in liquid propelled rocket engines.


Finding the source of a supplication

Question: Can anyone tell me the from which the following lines belong.. Ya Munazzilash Shafa'i Wa Muzh'hibad Da'i anzil 'ala Maabi Min Da'inn Shafaa'ann'...thanks.
Answer: يا منزل الشفاء ومذهب الداء انزل على ما بي من داء شفاء
It is not in the Holy Quran anywhere. It is from al-kafi: a shia book of hadith from the ahl-bayt.
Answer: The du'a you mentioned is referred to as a du'a made by 'Ali ibn Abi Taleb () in Shi'a sources such as Tib al-A'immah طب الأئمة  of ibn Sabur az-Zayyat ابن سابور الزيات (p.102 see here in Arabic) and Bihar al-Anwar بحار الأنوار of al-'Alamah al-Majlisi العلامة المجلسي (Juz' 92 page 78 see here in Arabic) as a remedy against a whole bunch of diseases such as leprosy, vitiligo and what is referred ti as the bad disease الداء الخبيث  (What ever that might be)

وعنه صلوات الله عليه وآله أنه قال ضع يدك عليه وقل يا منزل الشفاء ومذهب الداء انزل على ما بي من داء شفاء.

So it is narrated that 'Ali ibn Abi Talib () recommended to put the hand on the place where the disease is located and recite these words:

Ya Munnazila a-Shifa'a wa Mudhiba ad-Da' anzil 'ala ma bi min Da'in shifaa'an
 My own translation take it carefully
  Oh (Lord) who gives (descends) the healing and takes away the illness(es) give (descend) (on the) desease that has befallen me a healing

It appears also without the recommendation described above in al-Kafi (Juz' 2 page 567 see here in Arabic) of al-Kulayni.
Answer: This is likely to be a Du'a, but I can't recall one from what you have stated; however, I find some words from your quote that fit a specific Du'a and another that fit another Du'a.
The First Possible Du'a:
Ayesha (R.A.) stated that when anyone among them had an illness, Prophet Mohammad (SAW.) used to rub the area of the pain reciting the following dua:
In Arabic:

أَذْهِبِ الْبَأْسَ رَبَّ النَّاسِ وَاشْفِ أَنْتَ الشَّافِي لَا شِفَاءَ
  إِلَّا شِفَاؤُكَ شِفَاءٌ لَا يُغَادِرُ سَقَمَاً

Said in this way:

Alaahumma rabb-nnasi adhibil-ba'sa washfi wa antashafii laa shifaa' illaa shifaa'uk, shifaa' alla yughadiru saqama.

The translation in English:

O Lord of the people, remove this pain and cure it, You are the one
  who cures and there is no one besides You who can cure, grant such a
  cure that no illness remains.

(Bukhari, Muslim)
It is a Du'a for curing of any illness.

A Du'a from Qur'an about the same topic is when the Islamic prophet Ayyub said:
Surah Al-Anbya — Verse 83, in Arabic:

وَأَيُّوبَ إِذْ نَادَىٰ رَبَّهُ أَنِّي مَسَّنِيَ الضُّرُّ وَأَنتَ أَرْحَمُ الرَّاحِمِينَ

Recited in this way:

An-nee mas-sa-ni-yaD-Dur-ru wa 'AN-ta 'Ar-Ha-mur-raa-Hi-meen.

The translation in English:

Truly distress has seized me, but You are Most Merciful of those that
  are merciful.

The Second Possible Du'a:
Is a Dua' for supplication made against an enemy, in Arabic:

اللَّهُمَّ مُنْزِلَ الكِتَابِ سَريعَ الحِسابِ اهْزِمَ الأَحْزَابَ اللَّهُمَّ اهْزِمْهُمْ وَزَلْزِلْهُمْ

Said in this way:

Allahumma munzilal-kitab, sareeAAal-hisab, ihzimil-ahzab, allahummah-zimhum wazalzilhum.

The translation in English:

O Allah, Revealer of the Book, Swift at reckoning, defeat the confederates. O Allah, defeat them and convulse them.

Source for the 1st Du'a
Source for the 2nd Du'a

Finding the source of a supplication


Political rule by council

Question: What is the name of the political system ruled by nonelected council? Similar to corporate rule. I call it councilism, but looking for better name.
Comment: This is going to depend somewhat on the selection method for the council. For example a group of priests might be called a theocracy, or military leaders a junta. Not that those nouns are universally accepted to have a single meaning of course.
Comment: "Illuminati"? :)
Comment: People who already have de facto influence are selected. For example, the rich business people. The variation of Trilateral Commission with direct political power and council based decision making. Is a better name than oligarchy possible?
Comment: Plutocracy, i.e. rule by the rich?
Answer: In the generalities, a political system ruled by a few persons is an oligarchy:

Oligarchy (from Greek ὀλιγαρχία (oligarkhía); from ὀλίγος (olígos), meaning 'few', and ἄρχω (arkho), meaning 'to rule or to command') is a form of power structure in which power rests with a small number of people.

After that, there are a number of specific categorization that can be applied to the group, depending on extenuating circumstances.
Comment: I took the liberty of linking the Greek words to the lexical entries.  Hope that's ok.  Excellent answer!

Political rule by council


Embed PCP thermometers

Question: I was wondering if it is possible to embed the thermometer from an individual personal campaign page to another site. I am guessing it is, but don't know where the best place to look for the code is: anyone know?
Comment: Yes, this would be a great widget to embed in a facebook page.  I think you have to do some coding as noted below by @rayWright
Answer: Perhaps you could start with the widget code from a contribution page as a base?(Widget>widget.php)
Make a new one that pulls info based on PCP id vs contribution page id...

Embed PCP thermometers


Will I have to recheck my bags?

Question: I am flying from Halifax, Canada to New York, USA to Tampa, USA. I will be able to go through customs in Halifax. Will I have to recheck my bags at the New York airport?
Comment: Is this all on one through ticket, or are you changing tickets?
Comment: Welcome to [travel.se]. Remember to take the [tour]!
Answer: When you preclear US customs at Halifax Stanfield you will not need to go through customs again when reaching the United States. You arrive at a domestic terminal in the US rather than an international terminal and can proceed directly to your next flight. All you need to do is to make sure the airline checks your bags through to TPA, which they will do if your flights are on a single booking.
Answer: The airline should handle your luggage if both flights are part of the same journey on one ticket. If it's two separate tickets then you'll probably have to recheck your bags.
Comment: This is not always true for international flights, even if they are booked on the same ticket.  It is, however, true for most flights from Canada to the US, so long as your connection is through a US airport.

Will I have to recheck my bags?


What is meant by the term "quantum interference"?

Question: What is meant by the term "quantum interference" in the context of quantum computing and quantum algorithms?
Answer: The term is most often used in the context of the two-slit experiment. The interference pattern that you see, which is not simply what you'd get if you added the wavefunction ($\Psi_A$) associated with going through slit A to the wavefunction ($\Psi_B$) going through slit B, but there is a "mixed" term as follows:
$$
\tag{1}
|\psi|^2 = |\psi_A + \psi_B|^2 = |\psi_A|^2 +  |\psi_B|^2 + \psi_A^*\psi_B + \psi_A\psi_B^*.
$$
This interference pattern occurs even when you reduce the number of photons until there's only one photon at a time! When there's only one photon at a time, what could it possibly be interfering with to cause the patter on the screen to be different from $P_A + P_B$?
We say the photon interferes with itself. This is a quantum mechanical phenomenon that doesn't exist in classical mechanics.
The two-slit experiment was used by Feynman when he explained the Feynman integral, because the Feynman integral is a sum/integral over paths which each have an amplitude. These amplitudes interfere with each other, which again is a signature of quantum mechanical effects, since classically there would only be one path in the Feynman integral: the path with the smallest Lagrangian action.
Comment: It doesn't have "no meaning" in quantum computing. The meaning is the same here. For example the Mach-Zender ***interfer***ometer is frequently used to explain the concept of superposition of qubits for a photonic quantum computer: Without interference, there's no quantum computer.
Comment: Whoa.  Been reading a tiny bit and I actually understood that.  Thank you for that point about Mach-Zender interferometer! Highly instructive. I want to learn more about self interference. The symbol |Ψ|² makes sense to me, as does your equation. I really like the clear way math is written in this field.
Comment: thank you for your answer. Are you saying that *quantum interference* has no meaning in quantum computing, and this term is (and should) be used in the context of quantum physics?


Cold showers why?

Question: I saw a similar question asking why a shower gets hot/cold when toilet is flushed. My question is why does the person in the shower get cold If anyone anywhere in the house turns on the water? I cannot do dishes, run the washer or flush the toilet without someone getting froze out in the shower! Very frustrating!
Comment: I forgot to add I have well water in this home.
Comment: Not a duplicate. The question marked as duplicate asks why the shower gets cold OR HOT (though it only says cold in the title). Responses to the question marked as duplicate only answer why it gets hot. This question asks only why it gets cold.
Answer: If flushing the toilet results in COLD water coming out of the shower it sounds like a pressure issue.
Typically flushing the toilet (which reduces the amount of cold water pressure in the line), would cause the shower to become too hot.
However, if the pressure in your system comes prior to where the cold feeds the hot water tank, then flushing the toilet could cause a pressure reduction in the hot line causing the hot line to diminish.
Solution would presumably be a pressure tank addition to the feed to the water heater before the tank but after the junction with the cold water, and a check valve to ensure the tank can only pressurize in one direction.
Suggest strongly you consult a plumber on this.
Comment: I am not sure this is true with the new anti-scalding valves.  On the last 10-15 I have installed I have noticed exactly what the OP mentions, with any drop in pressure it goes cold.  You are absolutely right on older valves though.
Comment: Was there any mention of an anti-scalding valve in the OP?
Comment: "flushing the toilet could cause a pressure reduction in the hot line causing the hot line to diminish" -- Wouldn't it also cause a pressure reduction in the cold line? Then hot and cold pressures would be reduced equally and the shower would stay the same temperature. Why would pressure in the hot line (and not the cold line) be reduced?
Comment: Did you miss the first sentence in my answer?

Cold showers why?


Was there a process of impeachment if a king was found to be in violation of dharma?

Question: If a king was found to be in violation of dharma repeatedly and did not want to step down voluntarily, what were the options for the prajā?
Did they demand the king be ousted? Was there an "impeachment" process?
Answer: I have not seen any process of impeachment. However, the idea that an oppressive king should be removed is there in Hindu scripture. A king's plea that he is above the law is also rejected in Hindu scripture.
King and his duties

For fear of anarchy, Vena was made king, though he was not fit for it.
  Now that king himself has become the source of fear for the people.
  How can we secure the good of all beings?

Srimad Bhagavata Purana IV.14.9

A King will attain to joy in this world and the next, if he protects
  his subjects from oppressive officers and thieves, and collects taxes
  in accordance with the scriptural law.

Srimad Bhagavata Purana IV.14.17

Vena said: In the king is present all the Devas like Vishnu, Siva,
  Brahma, Indra, Soma, Agni, Varuna and all others who are supposed to
  bless and punish mortals. In fact the king is the embodiment of all
  the Devas. Therefore, O Brahmanas, without further ado, offer your
  worship to me, the King. Pay my taxes without stinginess. Who is there
  to be adored other than myself?

Srimad Bhagavata Purana IV.14.26-28

When the Rishis were moreover insulted by the pretentious scholarship
  of Vena, and when they found that their noble prayer for the welfare
  of the world as a whole was rejected, their anger was aroused, and
  they said: Let him be destroyed, let him perish. He is by nature a
  perverted monster. To let him live is to allow the worlds to be
  reduced to ashes. An evil person like him deserves not to sit on the
  throne.

Srimad Bhagavata Purana IV.14.30-32

King gets merits or demerits
The King derives his highest good by protecting his people. A King who
  protects his people well, will derive one-sixth of the merits of his
  subjects in the life hereafter. But a King who collects taxes from
  people without administering their affairs properly, will lose all the
  merits to his credit and will inherit the sins of his people to boot.

Srimad Bhagavata Purana  iV.20.14
Answer: No such thing as impeachment is found in the Smritis. But I've found something relevant in the Mahanirvana Tantra's 11th Chapter, which talks about Prayaschittas (expiatory rites), regarding what shall be the punishment for such a King.

[Lord Shiva says] O Kula−nayika! know that there are two kinds of sin−− that which
  contributes merely to the injury of one's own self, and that which
  causes injury to others (15). Man is released of the sin of injuring
  others by the punishment inflicted by the King, and from other sins by
  expiatory rites and Samadhi (16). Those sinful men who are not
  purified by either punishment or expiation cannot but go to hell, and
  are despised both in this world and the next (17). O Adya! I shall
  first of all speak of the Rules relating, O Maheshvari! to punishment
  by the King. The King who deviates from these himself goes upon the
  downward path (18). In the administration of justice, servants, sons,
  mendicants, friends, and foes should all be treated alike (19)
If the King is guilty of any sin himself, or if he should have wronged
  one who is not guilty, then he may purify himself by fasting and by
  placating those he has wronged by gifts (20). If the King should
  consider that he is guilty of any sin which is punishable by death, he
  should then abdicate his kingdom and go to a forest, and there labour
  for his liberation and penances (21). The King should not, without
  sufficient reason, inflict heavy punishment on persons guilty of a
  light offence, nor should he inflict light punishment on persons
  guilty of a great offence (22). But the punishment by which many
  offenders may be deterred from ill−doing, and (punishment) in the case
  of an offender who is fearless of crimes, should be heavy, although
  the offence be a light one (23).

So, the King has to punish himself. If he does not do that then that takes him downward, but that's in afterlife.
I have found no mentions of an impeachment.
UPDATE:
Similar verses, like the ones given above, are also found in Vashishta DharmaSutras' Chapter 17.

By failing to inflict punishment on a thief, on a cursed wight, on a
  wicked person, on one [caught] with weapons in his hands, on a thief
  caught with stolen property in his possession, on one covered with
  wounds and a cheat, a king shall fast for one night ; and the priest,
  for three nights. If an innocent man is punished [the king shall
  perform] a Kricchacha penance, and the priest [shall fast] for three
  nights.

And, from the 18th Chapter of the same Smriti:

THERE is penance for a crime committed unwittingly ; some [say] also
  for [a crime] committed intentionally. The spiritual teacher corrects
  the learned; the king corrects the evil-minded, but Yama, the son of
  Vivasvat, indeed punishes those, who commit sins secretly.

So, a king, who himself is guilty, has two options - either he has to do the prescribed penances or get punished by Yama in afterlife. The subjects can not overthrow him or question him it seems.
Comment: Thanks for the link @Bingming
Comment: If you are interested, you may check this answer https://hinduism.stackexchange.com/a/58681/24460, I have cited śāstras which support the action of subjects overthrowing an unjust ruler. Thanks
Answer: Concept of the divine king-Origin
The earliest evidence of the origin of kingship in India is found in the Aitareya Brahmana, a later Vedic text, which tells of a war between gods and demons .The gods were losing badly and needed someone to lead them in order to change the tide of the war.
It is through this legend, probably, that the concept of kingship arose out of military necessity and the need to have a king or a leader that could lead their subjects into battle. This suggests that for early Hindus in India the need for a king arose out of the need to protect their people and settle disputes between communities.  Thus it is reasonable to believe that a king needed to be able to understand the art of warfare and have a strong military background to support his people.
Kingship must have been an important issue because not much later , the Taittiriya Brahmana, also told the same story,but, with a slightly different version.The high god Prajapati sacrificed himself to let his son Indra become king for the people of India.  Although Indra was still tied extremely closely to the ideas of military leadership he was seen as the prototype for all earthly kings .This tie between the gods and the king, gave way to the idea that kings have a divine power and authority.
This concept of the divine king, placed the kings at a position above the rest of their people which also would have provided them with their authority.This concept would have needed to be constantly affirmed and therefore the king would need to maintain his Dharmic image in order to cement the relationship between himself and the Gods.
Answers to the specific questions

what were the options for the prajā?Did they demand the king be ousted? Was there an "impeachment" process?

As per the Manusmriti, the king was responsible/answerable only to God in the performance of his duties. Although, it was the obligation of the king to look after all the interests of his Praja(which was done as per tenets of the Dharmashastras), people had no power to impeach the king(or even criticize the king).
As per the Manusmriti Chapter VII:-

I will declare the duties of kings, (and) show how a king should conduct himself, how he was created, and how (he can obtain) highest success.
A Kshatriya, who has received according to the rule the sacrament prescribed by the Veda, must duly protect this whole (world).
For, when these creatures, being without a king, through fear dispersed in all directions, the Lord created a king for the protection of this whole (creation),
Taking (for that purpose) eternal particles of Indra, of the Wind, of Yama, of the Sun, of Fire, of Varuna, of the Moon, and of the Lord of wealth (Kubera).
Because a king has been formed of particles of those lords of the gods, he therefore surpasses all created beings in lustre;
And, like the sun, he burns eyes and hearts; nor can anybody on earth even gaze on him.
Through his (supernatural) power he is Fire and Wind, he Sun and Moon, he the Lord of justice (Yama), he Kubera, he Varuna, he great Indra.

Most kings were into worship rituals and yagnas,and did everything to please God. They were also very concerned of their reputation and building a good image amongst the people of their kingdom. And so, very rarely would a king violate any law.
Manusmriti, Chapters VII and  VIII, gives an insight into the meticulous "justice delivery system" which existed in a king's court, during the vedic times. Mentioned below, are some of the cases/rules, where the king could  incur sin/lose his kingdom/life:-

A king who properly inflicts (punishment), prospers with respect to (those) three (means of happiness); but he who is voluptuous, partial, and deceitful will be destroyed, even through the (unjust) punishment (which he inflicts).
Let him carefully shun the ten vices, springing from love of pleasure, and the eight, proceeding from wrath, which (all) end in misery.
For a king who is attached to the vices springing from love of pleasure, loses his wealth and his virtue, but (he who is given) to those arising from anger, (loses) even his life.
Through a want of humility Vena perished, likewise king Nahusha, Sudas, the son of Pigavana, Sumukha, and Nemi.
That king who through folly rashly oppresses his kingdom, (will), together with his relatives, ere long be deprived of his life and of his kingdom.
As the lives of living creatures are destroyed by tormenting their bodies, even so the lives of kings are destroyed by their oppressing their kingdoms.
Where justice is destroyed by injustice, or truth by falsehood, while the judges look on, there they shall also be destroyed.
'Justice, being violated, destroys; justice, being preserved, preserves: therefore justice must not be violated, lest violated justice destroy us.'
For divine justice (is said to be) a bull (vrisha); that (man) who violates it (kurute 'lam) the gods consider to be (a man despicable like) a Sudra (vrishala); let him, therefore, beware of violating justice.
One quarter of (the guilt of) an unjust (decision) falls on him who committed (the crime), one quarter on the (false) witness, one quarter on all the judges, one quarter on the king.
Neither the king nor any servant of his shall themselves cause a lawsuit to be begun, or hush up one that has been brought (before them) by (some) other (man).
Unjust punishment destroys reputation among men, and fame (after death), and causes even in the next world the loss of heaven; let him, therefore, beware of (inflicting) it.
A king who punishes those who do not deserve it, and punishes not those who deserve it, brings great infamy on himself and (after death) sinks into hell.
A king who (duly) protects (his subjects) receives from each and all the sixth part of their spiritual merit; if he does not protect them, the sixth part of their demerit also (will fall on him).
A king who does not afford protection, (yet) takes his share in kind, his taxes, tolls and duties, daily presents and fines, will (after death) soon sink into hell.
But that king who pardons the perpetrator of violence quickly perishes and incurs hatred.
A king who thus brings to a conclusion. all the legal business enumerated above, and removes all sin, reaches the highest state (of bliss).

Conclusion
The kings of yore had a unique relationship with God, as also their Praja(subjects).They always endeavoured to uphold Dharma as laid down in the Manusmriti. And, in a few exceptional cases, when Dharma was violated, kings did suitable Prayaschittas(atonement, penance, expiation) as advised by Maharishis and other advisors.
References:-1. Manusmriti, Chapters VII and VIII
2.Valmiki Ramayana and 3.Mahabharata
Reference link:-http://www.sacred-texts.com/hin/manu/manu08.htm
Comment: If you are interested, you may check this answer https://hinduism.stackexchange.com/a/58681/24460, I have cited śāstras which support the action of subjects overthrowing an unjust ruler. Thanks
Answer: As others have mentioned, there isn't really a formal impeachment procedure mentioned in śāstras afaik but they (śāstras) do mention circumstances in which the prajā might take an action against a Rājā or situations when they do take action.
Firstly, the paragon of dharma, venerable Manu states -

taṁ rājā praṇayan samyak trivargeṇābhivardhate /
kāmātmā viṣamaḥ kṣudro daṇḍenaiva nihanyate //
~ Manusmṛti (7.27)

When a Rājā administers daṇḍa with propriety/due deliberation (as detailed in Manusmṛti 7.26), he flourishes w.r.t trivarga, but the Rājā who's kāmī (acts upon kāma), viṣama (partial or prejudiced), & kṣudra (krodhana), is destroyed by that very same daṇḍa.

daṇḍo hi sumahattejo durdharaścākṛtātmabhiḥ /
dharmād vicalitaṃ hanti nṛpameva sabāndhavam //
~ Manusmṛti (7.28)

For daṇḍa is yukta with immense teja, and it cannot be wielded by those with uncultivated selves (untrained in daṇḍanīti). It assuredly destroys a Rājā who deviates from dharma, alongwith his relatives.
Yājñavalkya smṛti (1.355-357) follows and states similar to Manusmṛti (7.27-28). In Manubhāṣya on Manusmṛti (7.27b) , Medhātithi adds that such a Rājā is either detroyed by prakṛtikopa i.e. the kopa arising  out of natural dissatisfaction & unrest within the prajā, or some adṛṣtaphala. (prakṛtikopenādṛṣṭena vā doṣeṇa). In Manvārthamuktāvalī on Manusmṛti 7.27b, Kullūka Bhaṭṭa add similarly that such a Rājā is destroyed out of anger (caused by dissatisfaction) by mantris, etc. (nṛpaḥ sa prakṛtanaiva daṇḍenāmātyādinā kopādadharmādvā vināśyate). In support of this, Kauṭilya in Arthaśāstra (1.6.4-11) and Vātsyāyana in Kāmasūtra (1.3.34-36), state some famous negative examples of Rājās such as Dāṇḍakya, Rāvaṇa, Kārtavīrya Arjuna, etc. who got destroyed due to their actions (under the sway of indriyas or kāma, etc., and against dharma).
Anuśāsana Parva (61.32-33) solemnly sanctions the slaying of a Rājā in certain circumstances.

arakṣitāraṁ hartāraṁ viloptāramanāyakam /
taṁ vai rājakali hanyuḥ prajāḥ sannahya nighṛṇam //
ahaṁ vo rakṣitetyuktvā yo na rakṣati bhūmipaḥ /
sa saṁhatya nihantavyaḥ śveva sonmāda āturaḥ //
~ Anuśāsana Parva (61.32-33)

That Rājā who doesn't do rakṣā of prajā, simply plunders wealth, and who has no leadership. That Rajā is like Kali, and should by the prajā united, be slain. (32) That Rājā, who after declaring, "I will do rakṣā of you people", doesn't do rakṣa (of prajā), that Rājā must be slain like an unmatta & ātura dog, by the prajā combined. (33)
Aligning with Anuśāsana Parva (61.32-33), there's the following śloka

asaptapāpiṣṭhasacivo vadhyo lokasya dharmahā /
sahaiva parivāreṇa kṣipramevāvasīdati //
~ Śānti Parva (92.9)

That Rājā who with the aid of duṣṭa & pāpiṣṭha mantris goes against dharma, he becomes vadhya (one worthy of being slain) of all subjects, & endangers himself alongwith his family.
So, Śānti Parva (92.9) and Anuśāsana Parva (61.32-33) seem to be in favor of deposition (deposing the Rājā) and even regicide (particularly) of an adharmī & ayogya Rājā.
Manusmṛti (7.27-28) at least justifies deposition of such a Rājā, if not regicide.
Śukrācārya explicitly supports deposition of such a Rājā-

guṇanītibaladveṣī kulabhūto'pyadhārmikaḥ /
nṛpo yadi bhavettaṁ yu tyajedrāṣṭravināśakam //
~ Śukranīti (2.274)

Even a Rājā from great kula (or vaṁśa), who is a dveṣī of guṇa, nīti and bala (senā)  and adhārmika, then considering his conduct would lead (or if it really leads) to the destruction of rājya, his tyāga (deposement) should be done.

tatpade tasya kulajaṁ guṇayukta purohitaḥ /
prakṛtyanumatiṁ kṛtvā sthāpayedrājyaguptaye //
~ Śukranīti (2.275)

And in place of that Rājā, the purohita, with the consent of prakṛti (mantris, etc.), should do sthāpanā of another Rājā from that Rājavaṁśa, who is endowed with rājaguṇas.
In the śloka below, Śukrācārya states that it's not a pāpa for Brāhmaṇas to slay really wicked, tyrannical, etc. Kṣatriyas.

sudurvṛttaṁ yadā kṣatraṁ nāśayeyustu brāhmaṇāḥ /
yuddhaṁ kṛtvāpi śastrāstrairna tadā pāpabhājinaḥ //
~ Śukranīti (4.7.332)

If there's an atyanta durācārī Kṣatriya, the Brāhmaṇas may slay him. Even if the latter used śastras-astras (to execute the said karma) in a yuddha, there's no pāpa borne by them.
And there have been instances in itihāsa, which support Śukra's statement.
For e.g. the tyrannical & adharmī Rājā Vena was slain by the Ṛṣis. (Śānti Parva 59.93-94 ; Bhāgavata Purāṇa 4.14-15), and later his guṇavāna son Pṛthu (avatāra of Viṣṇu) succeeded as Rājā (was one of the greatest), who was acknowledged by Brāhmaṇas, siddhas, etc.
In fact, even the Mahābhārata war fought by Pāṇḍavas, was (from one perspective) their rebellion against the unjust regime of Rājā Dhṛtarāṣtra Kaurava, who was not upholding rājadharma. This is because, technically until Dhṛtarāṣtra was the Rājā of Kauravas, Pāṇḍavas were part of his prajā. And since all peace negotiations and entreaties proposed (to Rājā Dhṛtarāṣṭra) by the Pāṇḍavas failed, even Kṛṣṇa (who is dharmasvarūpa and ādarśa of ahiṁsā) supported the Pāṇḍavas in fighting against the Kauravas in a dharmayuddha. As Bhīṣma states, "Where there is Kṛṣṇa, there is dharma, and where there's dharma, there is jaya." (yataḥ kṛṣṇastato dharma yato dharmastato jayaḥ - Bhīṣma Parva 66.35). It's just that the Pāṇḍavas didn't indulge in deposing Dhṛtarāṣṭra or committing regicide, but the former attaining victory in the war and slaying all the sons of Gāndhārī (including adharmī Yuvarāja Duryodhana) left him no choice but to abdicate the siṁhāsana. Thus, here prajā takes action (via rebellion) against an unjust Rājā, and leaves him no choice but to abdicate the siṁhasana.
The numbering of ślokas from Mahābhārata follows the Gītā Press version.


DIY exterior door casing

Question: I have a couple of solid wood door slabs and wanted to install them into a casing that is weatherstrip friendly. Split door jamb casings don't seem to be compatible with this design, so I figured I'd make my own casings.  Based on the measurements of my existing exterior doors, it looks like it has a 1x5 for frame and 1x3 for the jamb.  Has anyone done this themselves and is it as straightforward to construct as I'm imagining (plus the latch hole and mortising the hinge of course)?
Comment: You seem to be misusing the word "casing", which is the trim that laps from the wall to the jamb edge. "Frame" and "jamb" are the same thing. Also, your question isn't clear. Please edit to ask something more specific than "is this straightforward". A photo or sketch would help, too.
Comment: Seems like he is trying to make an exterior rabbeted door jamb out of 2 pieces per side. The 1X5 is the main part so to speak and the 1x3 is the door stop.
Answer: The parts you are looking to cobble together, are already cut to the proper profile for an exterior door jamb on the shelves of the big box stores. The aluminum/wood sills are there too. The jamb is cut and ready to receive the typical weatherstripping used these days. here is a link to the product at one store
Comment: Thank you. This is exactly what I need and would cost almost the same anyway if I diyed it myself out of common board and weatherstripping.

DIY exterior door casing


C++11 thread pool implementation

Question: I am looking for a thread pool implementation based on C++11 threading facilities. The library should be preferably headers only. License has to be BSD style or MIT style permissive kind of license, i.e., no GPL.
Answer: There seems to be a GitHub of someone who developed a small library for C++ 11.
It also is just a central header file (no cpp files to add), and fits into your License requirements (it actually uses a permissive free software license).
Answer: I noticed this question trying to ask the same thing basically, except that I've already noticed a few, and I would like to get a proper recommendation/review of strengths and weaknesses rather than just a list. But for now, here's my list:

CTPL - A no-frills single-header-only library; has two variants: one only relying on the standard library, the other using a lock-free queue implementation from Boost. ~250 lines lines at this time.
threadpool11 by Tolga Hoşgör - "A fast, lock-free, cross-platform, full CPU utilizing thread pool implementation using C++11 features." claims to beat OpenMP in some benchmark; at the very least it means the author is proud and confident about it rather than just putting it out there... ~590 lines but that's with a lot more boilerplate license etc. So probably something like 500 lines.
thread_pool by Tyler Hardin - A single-class, 1 .hpp + 1 .cpp, library (the choice of code to put in the .cpp is very reasonable, so this is not a weakness compared to CTPL). ~290 lines
A Boost.ASIO-based 30-line threadpool implementation...

Now, I have not used any of these and cannot describe the differences between them, but would very much like someone with experience using threadpools to do so (in a separate answer).
Comment: So, I saw this in my referrer list on github. My library has changed a bit. It's still possible to use as a one header, one source lib, but it also has cooperative threading with a priority queue on POSIX now. This is really useful for solving recursive problems with a thread pool. Without yielding, it's impossible to avoid blocking while waiting on the results of subcomputations.
Comment: Oh, and it's also not C++11 compatible anymore. The last C++11 and 14 compatible versions are documented in the readme, though, so with a bit of git competence it's possible to get and use them.
Comment: @Tyler: Then, can you please edit my answer to reflect the state of your library right now? Alternatively, post your own, longer answer, describing the strengths and weaknesses of your library.
Comment: Note that those 30 lines about Boost.ASIO implementation is not quite fair (for comparison), since it uses other Boost facilities such as `boost::asio::io_service::work`, `boost::asio::io_service`, and `boost::thread_group`.
Comment: @DanielLangr: You are quite welcome to edit the answer and expand the the last bullet...
Answer: ThreadPool
ThreadPool is an easy-to-use header-only thread pool library using C++11 threading API, and no GPL.
Answer:
I am looking for a thread pool implementation based on C++11 threading facilities.

This is kind-of generic description. Basically, there are at least two types of thread pools. First, and much much simpler ones, allow you just to enqueue some jobs (tasks) represented by function objects and assign these tasks to running threads, which run these functors until they finish. If I am not wrong, all the recommended solutions work this way.
However, the main drawback of these simple solutions is that they are not able to suspend and resume tasks. This is anything but easy, and it is provided, e.g., by OpenMP or TBB. Consider the most simple example of using tasks for calculation of Fibonacci number with OpenMP:
int Fib(int n)
{
   if (n < 2) return n;
   int x, y;
   #pragma omp task shared(x)
   x = Fib(n - 1);
   #pragma omp task shared(y)
   y = Fib(n - 2);
   #pragma omp taskwait
   return x + y;
}

In this case, Fib function is suspended at the #pragma omp taskwait line and resumed (optionally even on different thread) after children tasks (tasks created in the task) are finished. You therefore need some mechanism to "jump out" of the function and "jump in" again (will coroutines from C++20 help?).
As for pure C++, I found two thread pool implementations that are a bit more complex:

cpp-taskflow — seems to be header only. There is what they call a dynamic tasking capability, which according to examples, allow creating new tasks within running tasks. But I cannot find the option to wait for the completion of children tasks.
dougbinks/enkiTS — not header only. There is some waiting mechanism, but I think it's "blocking" in the sense that the thread that executes the waiting tasks is not albe to execute another tasks during waiting.

However, I found these libraries by looking for regular tasking opitons in modern C++ and need to admit that I don't know much about them. It would be nice if anyone could provide more details.

C++11 thread pool implementation


How to get probability from the confidence score in SVM

Question: In liblinear library we can get confidence score (the distance between decision hyperplane) in SVM solver for a binary classification problem, but if i want a probability value for membership in any class, which is not directly available in SVM in liblinear, is there any way to transform the confidence score into probability value? My question is just: Can we get a probability value in SVM rather than just 0-1 value? The platt scaling can do this in libsvm, but the platt scaling suffers theoretical issues, is there other way?because I want to calculate the AUC for measuring SVM's classifying performance.
Comment: Your question is not clear.  Please review the site guidelines for asking questions.  Otherwise, I'm afraid you will likely not get any useful responses.
Answer: SVMs do not produce probabilities, so you can not obtain a probability score from just an SVM.
If you want a valid probability score, use logistic regression. Since you are using lib linear, the difference in performance between a linear SVM and linear Logistic model is minimal, but the logistic model will actually have real probabilities.
Note, there are various "probability calibration" techniques that can be used, such as Platt's scaling. Some more info in a blog post of mine here.
Answer: You're reasoning from a false premise. To compute AUC from the signed distances, all you need to do is compute TPR and FPR at each value of the signed distances for the observations in the hold-out set. ROC curves don't need probabilities as inputs. Actually, it's provable that ROC curves and AUC don't depend on having probabilities as inputs: if all positives have prediction 100 and all negatives -100, then the AUC is 1 because the probability that a randomly-selected positive is ranked higher than a randomly-selected negative is 1 -- exploiting the connection to the c-statistic.


SharePoint farm installation and partitioning

Question: I am going to be installing SP 2013 Standard in a farm config. We'll have four servers: 2 WFE/App servers, 1 SQL Server, and one app server dedicated to Search. On the SQL server, I plan on 2-3 partitions, 1 for the OS and 1-2 for the logs and databases. I am not sure about the WFE/app server or the search server, though. Any guidance is appreciated.
Answer: The advice from Waqas is good, I also like to have a "Data" drive (where I store site collection backups, and other exports). This allows me to have a backup drive that is different from the Logs and the OS drive.
Answer: For SQL Server:
1) 1 for OS(80GB), 1 for data files( size depend upon your data), 1 for log files
For WFE/App Server:
1) 1 for OS( 80GB) , 1 For the ULS Logs & IIS Logs ( because Logs chew all the space sometime, when enable the verbose and have operation going on),
Comment: Thanks (again) Waqas! How about the search server? I am reading about indexed partitions, but I don't know if that is the same as having physical partitions.
Comment: just to separate concerns I also like to leave the default system databases on their own partition, with their logs on yet another partition, because they have crazy high transactions.


Fresh grape juice and fizzing

Question: Grapes picked, denuded from stems, put through juicer, strained through fine cloth into bucket. Yeast growth noticed so removed from top of juice, restrained through fine clothe into bottles. Bubbles noticed in bottles and within 24 hours the corks on the bottles are popping. in other years I have juice at this stage but this year the process has sped up. No other ingredients added, just the grape juice. What is happening please?
Comment: Wild yeast is present on the grape skin, when crushing the grapes some yeast is present in the juice and starts fermenting your juice into wine.
Answer: Fermentation due to wild yeast.  You could try adding one Campden tablet (crushed) per gallon to slow it down but it will likely continue anyway.
Comment: Exactly, removing the foam from the top of the bucket will not eliminate the wild yeast.  You can freeze the the juice or use campden to get rid of the yeast.
Answer: Unfortunately you have figured out how to make wine. There isn't probably any way you can stop it short of sterile filtration, heavy use of potassium metabisulfites or freezing. You can let it run it's course and you'll have some wine or next time just freeze it and drink it when you need. The grape juice you see in the stores have been sterile filtered and chemicals added to stop fermentation. Good luck next time!

Fresh grape juice and fizzing


Can we use Line 6 Pocket POD on stage for live gigs?

Question: Line 6 Pocket POD does not have a foot switch. Still is it possible to use it for live stage show? Any technique anyone can suggest?
Comment: I'm not sure I understand the question. Can you explain why not having a foot switch is a concern?
Comment: Forgive me as I am new to setting up electric guitar and I sound cryptic. I think if there is no foot switch, I cannot quickly change the effect without bending down and pressing the small buttons on it. I am planning to buy a guitar processor that can be used for live gigs. Pocket POD is good option but I am concerned about its use in live gigs.
Comment: Ah. Well if you need to change sounds in the middle of a song, then no, Pocket Pod probably won't work for you. If you don't need to change sounds in the middle of a song, then it's not too strange to bend down in between songs. Is that all you were wondering?
Comment: Yes. Now after discussing I am convinced that POCKET POD is mainly meant for Live gigs/practice where there are no major changes in effects mid song. I will go for a processor which has a foot switch. Any recommendations of guitar processor around $150 and has foot switch and effects programming capability equivalent to POCKET POD?
Answer: I used the PocketPOD for live gigs several times and it is not ideal for it. It does not have footswith, plastic cursor switches are tiny and fragile. I also had problem with hum that was generated by PocketPOD when light dimmers were on even though I used ground isolated DI box.
If you need to change the sound during the song you may connect PocketPOD to your notebook via USB cable and use any DAW software to switch desired sound using MIDI Program Change event. You can even play with click from that DAW a let PocetPOD change the sound automatically on given measure in the middle of the song.
Answer: I'm pretty sure there's a belt clip available for it so that you can attach it to your strap. You might want to reinforce how it's attached with some duct tape (if it feels at all like it could fall off) or even just just tape it without the clip. Another option may be to attach it to a mic stand either with proper fixtures or my fave duct again. Do try this out in your practice sessions first rather than waiting until your gig.
Comment: Ahh yes in most of the cases belt clipping the POD will help... I think Pocket pod itself has a belt clip attached but the thing is to press the button I will have to pause playing for 3-4 seconds. That may break the rhythm.
Answer: You can definitely use these for live shows. I have seen people use them very successfully at small gigs and festival shows.
Yes, you aren't going to manage a quick patch change mid song, so if you need to do something like that you may need to add another pedal, but for many songs that isn't an issue (and you can use the guitar's volume control for boost if you need to play a lead line)
If you are looking at getting a device for gigs and you haven't yet bought the pocket pod, but think that you will need to be able to rapidly change patches, then you should go for one of the devices with a foot pedal. There are a few in the same price range.
(If you are competent with electronics, you could add footswitch capability, but it's really not worth your time, voiding the warranty, and the challenges)
Comment: I personally like Pocket POD with its low price and the effects it provides. My band has only one guitar player (me :) ) So I have to switch effects in between songs. I agree with you. Looks like without playing with the electronics inside there is no other method.


Rambam's Hilchos HaYerushalmi

Question: I am looking for Rambam's Hilchos HaYerushalmi (ed. Lieberman) (or a some other edition if it exists). Is it available for free online?
Comment: http://www.hebrewbooks.org/35920 found this if your interested. most likely not reliable in regards to the jirso
Comment: http://www.ybm.org.il/Admin/uploaddata/LessonsFiles/Resource/9995.pdf
Answer: Dr. Aviad Yehiel Hollander, secretary of the Jewish Law Association, has posted a recent article from R. Zvi Stampfer on his groundbreaking work on Rambam's commentary on masekhet Ketubot from the Talmud Yerushalmi. This includes manuscripts recently identified from the Fustat geniza that were not available to Prof. Lieberman when he published his work on Hilkhot HaYerushalmi. In addition to Rambam's commentary, R. Stampfer's article provides an extensive discussion on the history and findings of the manuscript (all in Hebrew).
Just to touch on something Maimonist mentioned, there isn't anything illegal about this copy AFAIK. The essay appears on the Yeshivat Birkat Moshe site (the book was a jubilee published by them in honor of R. Rabinovitz, RY of YBM), and Dr. Hollander has regularly publicized R. Stampfer's work at his request. But that said, you could always buy the book (MiBirkat Moshe, 2011)
Comment: It's on the Yerushalmi and I just edited the answer to clarify that.
Answer: It's not available that I know of (other than possible illegal copies). However, it is available in both print and electronic forms from JTS/Schoken Books.
Hope that this helps. Kol tuv.

Rambam's Hilchos HaYerushalmi


SharePoint Online Migration - Migrate external/SAML users?

Question: We are migrating from SP 2013 On-Prem to the cloud.  We currently use Ping Federate as the idP for our external users, but we intend to use the native external sharing options online.  Is there any way of doing user mappings or am I going to have to do this the long, hard way?  I'm using ShareGate and I can maintain the metadata for those users, but it's the permissions for these external users that I'm sweating over.  Appreciate the help!
Answer: Have you tried the CSV import for users?  This should get your external users into your O365 tenant, then you can use the regular ShareGate user mapping functionality to correctly map the user permissions.
https://www.kalmstrom.com/Tips/Office-365-Course/Import-Users-CSV.htm
Comment: Yeah, I gave that a shot.  You cannot import users from a different domain.
Answer: To migrate the external users, you'll need to find ways to do the following, probably with PowerShell.

Get a list of external user email addresses from the SharePoint 2013 environment membership provider
Cross reference that list with all the permissions assigned in SharePoint 2013
Create an Office 365 external user invitation for each email address in 1
Assign External user sharing permissions based on 2 and the invitation created in 3.
Comment: I found that I had to create user invitations for external users as a Member type, not a Guest type (Can be unlicensed).  My testing found that once I've done that, I can use ShareGate to select the external accounts for user mapping.  Still trying to confirm, but it appeared that before I migrate a site, I should migrate the SP groups first and then do the site migration.  If that works, then hopefully no cross referencing and adding permissions!


Should you explain where the level of detail comes from in a first person story that is in past tense?

Question: Sometimes I read a first person story  in past tense and I'm amazed at how much the main character is able to remember in such detail about events that happen decades ago. I know some books uses tools to explain the level of accuracy in the narration like a diary, letters, documents, video or audio recordings.
But some fiction books in first person never tells you anything about this, why is that? Am I meant to assume something or leave it a mystery?
Answer: In situations like that the writer is using a narrator who is describing events not from a perspective of after the story has ended, but of a perspective of immediately after it happens. When you think to yourself about actions you just made, or actions you just saw, it's mostly in past tense. "I threw the ball." Or "He ran." Etc. When describing objects, however, we use present tense. "The gun is against the wall." Or "His pants are grey." Having a narrator a few seconds in the future prevents the tense mixing that we naturally have in our minds that might be confusing or considered bad writing. Having the entire story as present tense is another way around it. It's just stylistic choice and preference
Comment: Thanks so much for the info! Hm what u say make a lot of sense. But the book I am reading now is The age of miracles by Karen Thompson Walker. Sometimes in this story the first person narrator  talks directly to the audience after some scenes and tells you the consequence of that event such as : It was many years after that event that we finally understood what it meant and looking back at it I regret doing it ( I am paraphrasing) . It feels like the narrator is talking to us after the fact. Many years ahead.
Comment: Oh I see what you mean now. In stories like that I think you're just suppised to assume the writer has spent a lot of time remembering the story and its details. Has actually gone over the story many times in their head or on the page depending on what kind of narrator you have, and have just been able to remember everything. It bugs me too but I just try not to think about it as frustrating as it is
Answer: At first, it would appear that the choice between past and present tense is binary. But the past starts a second ago and extends back for "a very long time". The further back into the past, the more unreliable that the narrator is likely to be. If there are several narrators, it is likely that each narrator will have a different perspective on the story and will remember different details of what did or did not happen. That perspective will certainly change over time: what is important to the young woman is not so important to that same woman who now has a dozen grandchildren.
You as a writer of fiction have the freedom to select the point of view that best serves your story. It is more work, but you might want to tell a simple story from multiple POVs to get a handle on how each POV contributes to the tone and texture of the story.


Origin of the latitude 36 of Eratosthenes

Question: How did Eratosthenes come up with the latitude 36 line, also called 36th parallel north, in the Mediterranean world? Rhodes was one of the navel points in his calculations and even today N36.00 goes through the southern part of the Rhodes. So I'd like to know the history of the calculation of this latitude and the origin of the latitudes in general.
Comment: A point may be that 36° is 1/10th of a full circle. Since Erastothenes famous derivation of the circumference of the earth also involved the elevation of the sun. I would use the conjecture the following procedure: At noon on an equinox, measure the angle between sun and zenith. If it is 1/10th of a circle, you are at the 36th parallel.
Comment: I think he got lucky. He was using locations that had similar lengths of day at the equinoxes/solstices. It just happened that one set ended up on what became the 36th parallel.
Answer: According to A Short History of Natural Science by Arabella Fisher:

He laid down the parallel of latitude in the following manner.  He knew that at all places on the equator the day was exactly the same length all the year round, and that the lengths of the days and nights varied more and more as you went northward; therefore he reasoned that, if he could draw a line east and west through a number of places whose longest day was exactly the same length, those places would be exactly the same distance from the equator. He began at the Straights of Gibraltar, when the longest day was exactly $14\frac{1}{2}$ hours, and then observing all those places whose longest day was also $14\frac{1}{2}$ hours, he drew a line through the south coast of Sicily, across the south of the Peloponnesus, the island of Rhodes, the bay of Issus, and across the Euphrates and Tigris, out to the mountains of India.  If you follow this line on a map you will find it is the $36$th parallel of north latitude and that Eratosthenes observation was perfectly correct.

Of course, Eratosthenes would not have identified this parallel as $36$ degrees north.  (According to Boyer's A History of Mathematics, the introduction of the $360$ degree circle came a little later.)  However, he could calculate its distance from the equator using the same techniques he employed in calculating the circumference of the Earth.
According to Boyer,

It is not known when the systematic use of the $360$ degree circle came into mathematics, but it seems to be largely due to Hipparchus in connection with his table of chords.

Hipparchus of Nicaea (ca. 180 - ca. 125 BCE).
Comment: The problem with the quotation from A. Fisher is that it assumes he had a map he could "draw lines" on. In fact, accurate maps only became possible after coordinates had been calculated.
Comment: @fdb Is Eratosthenes not simply inferring that each of the named locations lay on the same line of latitude, independent of any map which may or may not exist.  Here, Fisher's use of the expression "drawing a line" being metaphorical.
Comment: Yes, I think she is speaking about a figurative "line". But it is very misleading.
Comment: @fdb Yes, it certainly can be seen as a misleading expression.


Determining who died in the Spanish Flu Epidemic of 1918?

Question: I have several people in my family tree who died at a relatively young age in 1918 -- the year of the deadly Spanish Flu epidemic in the U.S. and Europe.  Unfortunately, I can't find death certificates for these individuals.  Did newspapers print the names of flu victims at the time?  Would statistical sources tell me which communities suffered from the out-break more than others?
Comment: Which country are we talking about here?
Comment: I think it likely that the subject is different enough in different countruies to warrant different questions.
Comment: @ColeValleyGirl - I'm looking for US records, but others might want records from overseas.
Comment: Seeking help to find one of those missing death certificates as a separate question would seem to be a more direct way to find the information relevant to your family.
Comment: @PolyGeo I've added an update to the bottom of my answer addressing the difficulty of finding US death records online for this period.
Answer: This will be a very general answer for the US, since we don't have a specific smaller jurisdicition, showing the types of resources that can be found.
Be on the lookout for webinars discussing the use of social history for genealogy, like the ones listed below. You'll see what kind of material can be found if you explore websites and repositories that have a wider focus than just genealogy.

"What Is Social History and Why Should a Genealogist Care?" presented by Annette Burke Lyttle, hosted by the Minnesota Genealogical Society on 3 May 2017.
"Incorporating Social History Into Your Genealogical Research" presented by Dr. Michael Lacopo, hosted by the Southern California Genealogical Society on 15 Apr 2015, and by the Santa Barbara County Genealogical Society on 23 March 2017.

Resources for North America:

Spanish Influenza in North America, 1918–1919 (Harvard Libraries Open Collections) has a bibliography and links to items in their collection [thanks to Annette Burke Lyttle for this link]

Individual states or localities could have reports like these:

A special report on the mortality from influenza in New York State during the epidemic of 1918-19 (Google Books)
Spanish Influenza Epidemic in Georgia (Georgia Archives, via DPLA)

Local Histories like this one might have lists of victims:

A Standard History of Portage County, Wisconsin (Google Books)

Local Historical Societies:

Newspaper articles on Spanish flu (Wisconsin Historical Society, via DPLA)

Copies of Local ordinances with regulations about how to report outbreaks:

Public Health Reports: Supplement U.S. Government Printing Office, 1921 (Google Books)

Links for newspaper research:

The Ancestor Hunt: Newspaper Research Links
Online Historical Newspapers
US Newspaper Directory, 1690-Present at Chronicling America [Library of Congress]

Other Library resources:

Digital Public Library of America
World Cat
Archive Grid

Don't neglect local public libraries -- they might have 'vertical files' with newspaper articles or obituaries of local residents who died.
Additional Resources on finding death records:

FamilySearch's Research Wiki has extensive information on each US state's vital records, with tables showing when statewide registration starts, and when general compliance was reached.  They generally have information about where you can write for records if necessary. Before statewide registration, you need to contact the county where the death occurred, which is problematic if you don't know that information.
Joe Beine's guide Online Searchable Death Indexes and Records is a directory of online death records for most states and some large counties such as New York City, Los Angeles, etc.
Be aware that if someone died away from home and was buried back home, there may be more than one death certificate, or burial transfer permits. See the post Death in the wrong place and other posts about death records from Judy G. Russell's blog The Legal Genealogist.
Answer: The epidemic was a world-wide event:
My local genealogical society (Perth County Branch, Ontario Genealogical Society, Canada) has published a 21 page booklet on the epidemic, "Avondale Burials, Spanish Influenza Epidemic 1918" (2001, non-electronic), with articles and obituaries from Stratford newspapers, listing quarantines, death tolls and other news pertaining to the epidemic.
The parish register of my mother's home village (Transylvania, Romania) includes Spanish flu as cause of death in many burial entries during the epidemic.
Quite likely, the 100th anniversary of the epidemic will be commemorated in some way in many places.
(Although not a significant offering, the above was not really appropriate as a comment to Jan Murphy's answer).
Comment: Is the OGS booklet available? If so, link please?
Answer: If you can find newspaper obituaries for these people, there will probably be a cause of death included. While not as conclusive as a death certificate, it may at least allow you to rule some things out. And if you look at other obituaries in the same locality within the same week or month, you might see a pattern.