The rock that gives birth to quartz sand

Question: Thanks to one minute of the Earth we know that beach sand mother rock, besides the quartz itself, is (or was?) made of olivine, amphibole and orthoclase. I wonder, what is the name of that rock and where do the 3 annihilated minerals go if only quartz is left?
Comment: Short answer: the rock name is granite (it has no olivine by the way). The other minerals turn into clay (also known as dust, or mud).
Answer: In only one minute of presentation there isn't time for detailed discussion, so one has to make broad generalizations which, on closer inspection, aren't quite true. It is true that most sand is made of quartz, and that most of this quartz arises from weathered granitic rocks, of which the main minerals are quartz, orthoclase and plagioclase, usually with some mica, quite rarely some amphibole and almost never olivine. In the magma olivine and quartz react to make either amphiboles (if it is a very hydrous melt) or pyroxenes.
It is possible to find a sedimentary rock made of weathered out quartz and feldspar grains. Depending upon the original chemistry the feldspar could be potassium-rich (orthoclase) or sodium-calcium-rich (plagioclase). The resulting sedimentary rock is known as an arkose. Arkose is common in dry areas of eroding granite, such as the dryer parts of sub Saharan Africa. However, it is much more common for the weathering to involve wet erosion - thousands of cycles of rain and sun, hot and cold, in which case the feldspars mostly decompose to clay (many varieties and sub-species).
Olivine is much more characteristic of basic volcanic rocks, especially basalts, which do not weather to yield quartz grains. Another rock type in which olivine is a major component is peridotite. This weathers to yield goethite (a kind of ironstone) and serpentine. Occasionally, if the pyroxene to olivine ratio is sufficiently high, the weathering can yield quartz as a secondary by-product.
Another feature of quartz: Over long periods and especially at high temperatures and/or high pressures, it is very slightly soluble. Not that you would notice. The sand isn't going to dissolve beneath your feet, but every litre of surface water contains a few milligrams of dissolved quartz as silicic acid, which takes part in a whole catalogue of geological processes. In addition, there are many other rocks besides granite which yield quartz grains, including quartzite, weathered pre-existing sandstone, schist, gneiss, and some intermediate rocks (complex chemistry between granite and basalt. Even limestone - rocks that are generally thought of as 'pure' calcium carbonate, generally have a percent or two of insoluble residue, of which quartz is the dominant component.
Comment: "In the magma olivine and quartz react" - quartz and Mg-olivine never coexist at any stage in magmas. Basaltic magmas do not crystallise quartz, and granitic magmas do not crystallise olivine.
Comment: Michael is right, as most olivine is about 85% Mg end-member, but if I remember correctly, fayalite, the much rarer iron end-member version of olivine, can co-exist with high temperature silica in the form of a fayalite-tridymire eutectic.
Comment: "much rarer" is an understatement when discussing igneous rocks. It exists maybe only in charnockites.
Comment: Michael - correct again. OK, for 'much rarer', read 'extremely rare'. I have only ever read about it - in 40 years as a geologist I have never actually seen fayalite-tridymite in the same rock.
Comment: I see now that orthoclase and plagioclase are just [feldspars](https://en.wikipedia.org/wiki/Feldspar). This means that every 3 molecules of SiO2 has one molecule of Al and some other molecule attached. How can weathering weather the 'crystals' of the Al (K | Na | Ca) out? Separate atoms of metal can hardly be called 'crystals', IMO.
Comment: Actually, it isn't separate 'molecules' of SiO2. The feldspar 'molecule' is a framework structure of alternately upward and downward pointing silicate tetrahedra with 'X' cations filling in the empty slots to match up with the anionic points of charge. The general formula is XAlSi3O8, where X is generally Na or K. If Ca is present then the extra positive charge is balanced by Si deficiency as in anorthite, CaAl2Si2O8.  The metal ions, on their own, are neither crystals nor molecules.


Why was Newton's observation of the falling apple significant?

Question: As described in this article at Wikipedia, in 1666, Newton was in a garden when he noticed an apple falling. Surely, Newton could not have been the first person to notice that things fell when dropped. I'm sure many gardeners saw that happen and I found evidence from old stories about Galileo Galilei dropping items from towers and other stories about people struggling to build winged machines which seem proof enough that people noticed that things tend to go down. So why was Newton's observation of this behavior so much more significant?
Comment: When elementary schoolmasters and science collide terrible things happen.
Comment: I think you've nailed it.  The falling of the apple wasn't significant.  Newton's observation was significant.  Gravity existed prior to Newton, but Newton helped us to understand gravity.
Comment: @TylerDurden That is a rather offensive statement.
Answer: The observation that apples fall to the ground is not significant in itself. What matters is the conceptual jump that Newton performed, while (as he reports) sitting in his garden. Before Newton, the conundrum was expressed as: "if apples fall, why does the Moon stay in the sky ?". The breakthrough was Newton suddenly realizing that it was the wrong question: the Moon is also falling toward the Earth ! But it has enough lateral movement to "keep missing" (that which we now call "being in orbit").
Newton could think that because he had already come up with the realization that when an object moves, it has, by itself, no reason not to keep moving: you have to push a trolley to set it in motion, but you also have to do something to stop it. Prior to Galileo, everybody was convinced that a moving object could not keep moving indefinitely; every object, by itself, had to stop. Galileo was first to demonstrate that it was not true -- actually, the first to come up with the idea that trying things out was a better way to demonstrate things in physics than just thinking about them abstractly. Newton, with new mathematical tools ("infinitesimal calculus" -- an idea that Leibniz also got independently at around the same time), could formalize it as his first law. With that knowledge, he could imagine, finally, that if the Moon had some lateral movement, then it would keep on having lateral movement and thus keep on missing the Earth while it falls towards it.
It all crystallized in his head at some point where he was, mostly, at rest in a quiet environment. As Nietzsche is believed to have once said: "all truly great thoughts are conceived by walking." It is thus kind of fitting that Newton made one of the biggest advances of physics of all time while observing something as mundane as an apple falling. Such is the way the human brain works.
(Incidentally, the apple story has been used to pinpoint the exact date of the scientific breakthrough, since apples fall only at a specific period in autumn. However, the story is a nice story that was reported only by Newton, who knew how to sell his ideas, so the story might be a myth after all.)
Comment: *Before Newton, the conundrum was expressed as: "if apples fall, why does the Moon stay in the sky ?"* I don't think this is quite right. Before Newton, nobody would have asked such a question. Gravity meant the tendency of material objects to go downward, as opposed to levity, which was the tendency of fire and clouds to go up. Nobody would have imagined that gravity acted on the moon, or that the apple and the moon could be in the same category. Newton's insight was that a single set of universal laws could be made to apply to both the heavens and the earth.
Comment: I created an account just to upvote you.  Lovely answer.
Comment: I believe the story was recorded by Newton's niece, not by Newton himself.
Comment: @BenCrowell those are two interesting observations, and would deserve something more than a comment.
Comment: @BenCrowell: I think that one would be Galileo's story, not Newton's. A big part of the controversy around Galileo was his insistence on trying to "do physics" on celestial bodies; this was fueled by his discovery (with the first astronomical telescope) of mountains on the Moon, which was thus not as "flawless" as Aristotle would have liked.
Answer: To add to @Thomas-Pornin's answer, and Ben Crowell's comment, Newton understood that a force was acting on the apple. The question was how high the apple would have to be before the force stopped acting. As in, why doesn't gravity act on the moon? Newton's insight was that the force never stops acting, it is a universal force.
Answer: Newton understood gravity long before the apple fell before him from the tree -- his explanations, however, came across as the mindless drivel of a lunatic to the common man of the time.
Surely for the unfortunate genius Newton, coming up with a way to get these people to understand something so obvious to himself was the hard part!
The apple falling from the tree was the story that finally struck a chord with his audience for long enough for them find value in trying to understand why Newton was trying to tell them.
Comment: Newton was not interested in communicating with what you call the common man of the time. To begin with, he wrote his books in Latin, and expressed himself in terms of abstract mathematics. He was writing for other scholars.
Comment: This answer seems to be pure conjecture.
Comment: why did he have to or why did he try to explain his theories to the public.. Why not just communicate with his peers and enjoy the privilege of not having to descend to the level of the public?
Comment: @barlop, he certainly did not _have to_ explain anything to people, & +fdb perhaps he knew better than to even try teaching things they wouldn't get -- but apples falling from trees was a concept he could relay to a passer-by without so much as slowing his stride.

Whether he was excitedly sharing knowledge or disinterestedly placating people bugging him, the falling apple explained an otherwise inexplicable phenomenon in a way they could clearly understand and pass along, and made so much sense to people that _God_ himself was supplanted by gravity as the most believable explanation.


Is there any constitutional precedent or laws against bills of "anti"-attainder?

Question: In South Dakota an attorney for adults sexually abused as children by priests and nuns contended that the state legislature passed a statute of limitations (in approximately 2010) preventing lawsuits and/or prosecution for such crimes and thereby rescued the alleged perpetrators from accountability. That's what I have tentatively labelled a bill of "anti"-attainder. So, is this allowable generally, or do precedents or custom require extensions of statute of limitations to take effect much later, after any current victims are likely to be dead, as a guarantee to those victims of due process if they come forward? Because it seems to me the legislature could otherwise be bribed to protect perpetrators ex post facto.
Comment: Another name for similar legislation is a "legislative pardon" often accomplished via a "private bill." They are not categorically forbidden at the federal level, but many state constitutions prohibit or limit this practice.
Comment: Is [jurisdiction stripping](https://en.m.wikipedia.org/wiki/Jurisdiction_stripping) what you are looking for?
Answer: A Bill of Attainder, as described in this question is a legislative act which declares a person guilty of a crime, without a judicial trial. Therefore, an "anti-Attainder" would logically be a legislative act which declares a person not guilty of a crime, without a trial or overruling the outcome of a trial. As a comment mentions, this is more often known as a "legislative pardon". In most US states the pardoning power is given to the Governor, in some cases together with a "Board of Pardons' or "Board of Parole". Legislative pardons are rare, and in some states are not allowed.
Changing the statute of limitations on a crime does not affect only a particular named person or people, but rather anyone accused of that crime. The legislature may (if it so chooses) shorten the statute period at any time, and the shortened time period will affect anyone against whom formal charges have not yet been filed. The legislature may also lengthen the period. I believe that such changes also take effect for anyone not yet charged, but an argument might be made that as applied to someone accused of committing the crime before the extension was passed, the is an ex post facto law. I don't know of any court decision so holding.
The legislature may also at any time repeal the law making some act a crime. In such a case, anyone not yet charged could not be charged in future. I am not sure if people already charged, or even with trials in progress when the repeal is effective, would be entitled to a dismissal as of right, but I think there normally would be a dismissal as a policy matter. Look at recent repeals of laws criminalizing possession of certain quantities of marijuana in some US states as examples.
In such matters the legislature acts on whatever basis it sees fit. Political pressure is probably more likely than true bribery, but corrupt legislatures are not unknown. On the other hand, pressure to repeal or modify a law seen as unjust or overly harsh can lead to legislative actions. In any case, this is a political matter of legislative choice.
Comment: A pardon means that an offender is not punished; it does not mean he is not guilty, and indeed some people wrongly condemned have refused pardons for this reason(see [wikipedia](https://en.wikipedia.org/wiki/Pardon). OP seems to be suggesting a bill that would make certain crimes non-prosecutable, though how this differs from legalisation is not clear.
Comment: @Tim Lymington  A pardon generally means that all **legal** consequences of a conviction are reversed or removed, and the person is considered legally not guilty. Thje Wikipedia article says that in **some** countries accepting a pardon may  be an admission of guilt. Not in the US, I  think. It also says that pardons are sometimes used when the executive thinks that there has been a wrongful conviction. Consequences such as denial of licenses or voting are undone by a pardon.

Is there any constitutional precedent or laws against bills of “anti"-attainder?


Folder weekly backup?

Question: I want to backup a folder on my hard drive every in another folder under say a new folder saying backup-01-01-2010?
Also if it is possible to schedule this on a weekly basis?
Comment: Is there a reason windows backup won't work for this?
Answer: Syncback Freeware allows you to do that. You can schedule the backups whenever you like and using special variables, you can specify the date as part of the destination backup folder. See an example here.

Folder weekly backup?


Hardware question

Question: I am looking into a super resolution project  ( Increasing image resolution ) and was thinking of building a hardware to snap multiple pictures. A question about building a hardware definitely seems off topic to DSP. But who better to answer / give suggestions this than DSP folks? Should I post such questions? Where is such a question best suited?
Answer: I think electronics.stackexchange.com would be a more suitable place for that.
Answer: Questions about HDLs (Hardware Description Languages) such as Verilog or VHDL are welcome on https://stackoverflow.com/. HDLs are used for creating custom chips (ASIC) or programming FPGAs.
Any questions regarding discrete components is probably best served by https://electronics.stackexchange.com/.

Hardware question


Authorship of Rashi's Bible commentary

Question: Besides for the commentary on Divrei Hayamim (which as noted here was not written by Rashi), is the authorship of any of the commentaries to the Bible attributed to Rashi disputed?
Comment: Mayer Gruber's introduction to "Rashi on Psalms" has a pretty good overview of the various opinions, and whether or not we should question his authorship on Psalms, the last sections of Job, and Ezra-Nehemiah
Comment: @MoriDowidhYa3aqov Just saw it. Haven't had a chance to read it yet. Much appreciated!
Answer: Chida in Shem Hagedolim (page 7 of the file) quotes Seder Hadoros, who says that the commentary on Iyov isn't from Rashi. On that same page he also quotes someone who claims that none of the commentary on Neviim is from Rashi, although he disagrees with that.
Comment: @mevaqesh I don't carry around a frumometer to measure anyone's frumkeit, but I can tell you that Gruber does not usually wear a yarmulke but Moshe Sokolow does and lives in a frum community
Comment: See the article by Moshe Sokolow, "Establishing the Text of Rashi's Commentary on the Book of Job," PAAJR 48 (1948). He doesn't think this claim should be taken seriously (and the Chida himself didn't seem so sure to me)

Authorship of Rashi's Bible commentary


How to compose (a starting point)?

Question: I am asking for any idea or starting point in order to learn composition on my own. My goal is to create my music and unlock creativity, but I do not know where to start or how to start. I know some basics of music notation and some concepts and definitions like chords, scales and melody, but do not know how to make it always sound good if there is any rule for that. Any good reference or book would be useful. I don`t want to follow any style, but I want some "freedom" to express myself musically, and that freedom has to do with knowledge also... any tips or advice ?
Comment: possible duplicate of [Any advice for a novice composer?](http://music.stackexchange.com/questions/1809/any-advice-for-a-novice-composer)
Comment: @user3533: You seem to be asking for resources for learning composition and music theory. This is not it, but might still be helpful or inspirational: [Finding the starting point when creating a composition or score](http://music.stackexchange.com/questions/10000/finding-the-starting-point-when-creating-a-composition-or-score)
Answer: This might sound silly, and at least initially you might feel so while doing this, but I suggest carrying a dictaphone with you anywhere you go, also while inside your own house, or even when you go to the toilet. You will get inspiration from the most unusual items and events, and at most unusual times; maybe some territorial dispute of birds on some tree, sound of sparkling fountain in the wind, people walking, e.t.c. and you don't want to miss the moment to record your inspiration, or your own original idea, and let it resonate for a while in your head, before you listen to your recording at a later date and actually start assembling separate pieces into more coherent, complex compositions.
Don't complicate when you're recording your ideas. Hum, whistle, or sing a melody you thought of in your dictaphone as soon as possible, narrate ideas for lyrics, tap with your hands on your thighs, with fingers on trash cans, anything that wouldn't be considered offensive to other people around you. Ask permission if you deem it necessary, but never part from your dictaphone (or any other handy recording device, such as your smartphone,...) and don't let social situations distract you to the point you forget your ideas. I suggest you carry your dictaphone around with a neck strap, with the recording button easily accessible at any time.
When home, upload your recordings to your computer, split individual ideas to separate files, organize them in to you meaningfully named folders for easy access, and use them in all kinds of software that is available, converting your humming to musical notes, sample recorded sounds for backgrounds, narrated texts for lyrics, e.t.c. You will most likely use loads of different softwares for this, so I won't go into their use.
If you play any musical instruments, try your ideas on them too, see what you'll make of them when they sound different. If you don't - learn some. You don't have to become a maestro to use them for composition purposes. And - experiment! Most of what will come out might not be to your liking, but don't discard your previous ideas simply because you don't see them aesthetically or otherwise befitting to anything else you recorded for the time being. You're creating your musical playground, and you'll need as many toys to play with as you can get your hands on. Create your sandbox, where you can test them out - this will most likely be various software nowadays, but use those you're most comfortable using to evolve your ideas. Only start complicating your creative processes when you believe there's absolutely no other way left, or to apply the final layer of polish to your creation.
And perhaps most important of all - enjoy being creative and don't ever let unfavorable critique discourage you or affect your ability to express yourself through music. Impressions are just temporary, while expressions are timeless.
Comment: I would note that, although you don't have to be a virtuoso, understanding music and being at least proficient on at least one instrument are indispensable to a composer. The more music theory you know and the more instruments you have a feel for, the better you will be able to compose.
Answer: In the words of Neil Gaiman "Just Start".
Write a single note, then write another note. Congratulations, you have 2 notes!  Now add another, and a fourth.  I know this seems trivial, but a composition is not made of a giant leap from the start to half way through.  It's a thousand tiny steps, modifications and backtracking.
Getting personal, this is a problem that can be overcome just by throwing notes at a page.  If you have a melody or concept to follow then great! but it's not needed just to start.  When I write without a start point I'll allways find that the development, or some element of what I write comes out well, and then you can store it and use it later in either another composition, or as something to centre your current composition on.
I believe this is how the pro's think because I wrote a piece start to finish without chopping and changing and at a workshop the teacher said that it seemed like an early sketch of a composition
Now on to some practical resources that are helping/have helped me.

The Study Of Counterpoint
A great book that I began my compositional theory in, because it gives rules so simple and clear, that a machine could follow them.  Get Notion if you have an Ipad, Musescore if you have a PC, or use whatever instrument you're used to to play the exercises.
The limitation of this book and you'll find fairly quickly is that it restricts certain note combinations that you would nowadays completely allow, but for creating a good grounding in harmony and counterpoint in perticular I would reccommend this as the starting point a million times over.  By the end you'll be able to take a bassline of whole notes and write a 4 part harmony using every note value from a semibreve to a crotchet.
Guide to the Practical Study of Harmony
Written by Tchaikovsky, This is the book I'm studying at the moment.  From the very first exercise this book produces beautiful results.  It talks about how to connect chords, write extended tonalities and much more. I can't praise it enough, but I've only just started so I'll say no more.
Online articles and music.StackExchange
The internet is just full of astounding articles on music.  While not many will delve as deep as books will, the internet allows you to answer almost everything that has been done before in music.  More information is uploaded to the web every day than the entire world had during the time of Tchaikovsky, and porn aside there's no shortage of great resources.  The great thing about this site is that you can explore every aspect of music writing, and I encourage you to compose until you hit a snag, and then solve it on here.
Above all, keep at it.  It is not through force, but through repetition that water wears down the stone.
Answer: If you understand enough about chord relationships, you can listen to songs you like, then mimic and slightly change them. Just taking the ending to "Stairway to Heaven", an oldie but goodie, do you like the A minor, G, F chord sequence? What if it were A minor, G, C instead? Can you play it in D, such as D minor, C, Bb? Can you put your own melody over it?
I also agree with comments to keep a recording device around, and 'just start'. You record because some of the best ideas come at surprising times. Then, if you doodle on the piano, and find two chords you like together, can you put a melody over them and repeat? New age music can start that way.
Answer: Learn how harmony works. II V Is. The process of tension and resolution. Dominant chords resolving down by fifths. Cadences. That kind of stuff. I wrote a book called "Understanding and Implementing Harmony". You can check that out if you like (amazon). Or you can look at Bert Ligon's "Jazz Resources" book or Tim Richard's "Exploring Jazz Piano" book.

How to compose (a starting point)?


Right word for repeating something several times to make one believe that the thing is true

Question: What's the right word for repeating something several times to make one believe that the thing is true?
Comment: Can you supply a sentence with the word you want missing? As it stands, a wide range of words could answer your question.
Comment: Sounds like ***brainwashing*** to me.... ;-)
Comment: Who is one repeating it *to*? Oneself or someone else? I think you mean the former, but I'm not sure.
Comment: A *self-fulfilling prophesy*
Comment: It is not clear whether you are asking about stylistic devices in the language or philosophical modes. I assumed the first.
Comment: The lady doth protest too much, methinks.
Comment: @HotLicks   I've heard that before in a different context, said ironically of someone who keeps declaring they will do something they know they won't.
Comment: *The Big Lie*. Actually, the idea is that repeating the lie over and over will not make people believe it as it is stated, but it will have the effect of making them think there is probably some truth to it.
Answer: "proof by assertion", a fallacy, must be the phrase you are looking for.

Proof by assertion, sometimes informally referred to as proof by repeated assertion, is an informal fallacy in which a proposition is repeatedly restated regardless of contradiction. Sometimes, this may be repeated until challenges dry up, at which point it is asserted as fact due to its not being contradicted (argumentum ad nauseam). In other cases, its repetition may be cited as evidence of its truth, in a variant of the appeal to authority or appeal to belief fallacies.

This fallacy is often used by politicians during election times.
Comment: I like the *argumentum ad nauseam* inside there.
Comment: This is right for a philosophical mode.
Answer: Stylistically, there are many:
Here they are, some are Latin or Greek-based words, which is OK, since we seem to be discussing rhetoric. Many though are also used in their English form, which I am not going to work through  here:
Repetition of ideas
commoratio:
Dwelling on or returning to one's strongest argument.
disjunctio:
A similar idea is expressed with different verbs in successive clauses.
epanodos:
Repeating the main terms of an argument in the course of presenting it.
epimone:
Persistent repetition of the same plea in much the same words.
exergasia:
Augmentation by repeating the same thought in many figures.
expolitio:
Repetition of the same idea, changing either its words, its delivery, or the general treatment it is given.
homiologia:
Tedious and inane repetition. Unvaried style.
hypozeuxis: an expression or sentence where every clause has its own independent subject and predicate.
palilogia:
Repetition in order to increase general fullness or to communicate passion.
pleonasmus:
Use of more words than is necessary semantically. Rhetorical repetition that is grammatically superfluous.
scesis onomaton:
A series of successive, synonymous expressions.
synonymia:
The use of several synonyms together to amplify or explain a given subject or term. A kind of repetition that adds force.
tautologia:
The repetition of the same idea in different words, but (often) in a way that is wearisome or unnecessary.
traductio:
Repeating the same word variously throughout a sentence or thought.
http://humanities.byu.edu/rhetoric/Figures/Groupings/of%20Repetition.htm
Comment: I don't either. The question is kinda broadly formed.
Comment: Yeah, well, I really don't see how one can downvote this. Not that I even give a damn.
Answer: I'm not sure whether you mean repeating it to oneself or to someone else, but in case the latter, then:
Propaganda
From the Wikipedia article "Propaganda techniques":

This uses tireless repetition of an idea. An idea, especially a simple
  slogan, that is repeated enough times, may begin to be taken as the
  truth.

Emphasis mine.
Repetition is essential to propaganda:

But the most brilliant propagandist technique will yield no success unless one fundamental
  principle is borne in mind constantly and with unflagging attention. It must confine itself to a
  few points and repeat them over and over. Here, as so often in this world, persistence is the first
  and most important requirement for success.

Mein Kampf, Adolf Hitler, 1925. Translated by Michael Ford, 2009. Emphasis mine.
Answer: Simply, the term argument by repetition can be found at Logically Fallacious which details over 300 logical fallacies.
Answer: I think autosuggestion is close to what you are looking for:

an influencing of one's own attitudes, behavior, or physical condition by mental processes other than conscious thought.

(M-W)
Answer: Perhaps brainwashing (Dictionary.com):

2. any method of controlled systematic indoctrination, especially one based on repetition or confusion:
  brainwashing by TV commercials.
Answer: There are "self-help" practices called self-statements, self-affirmations or simply affirmations.
According to the Association for Psychological Science, these are statements people repeat over and over to themselves with the aim of eventually believing them. Source
From the Wikipedia article "Affirmations (New Age)":

More specifically, an affirmation is a carefully formatted statement that should be repeated to one's self and written down frequently.

Emphasis mine.
Answer: It is known as the Illusory truth effect and is a cognitive bias (memory). It works because:

People are more likely to identify as true statements those they have previously heard (even if they cannot consciously remember having heard them), regardless of the actual validity of the statement. In other words, a person is more likely to believe a familiar statement than an unfamiliar one.
Answer: Not certain of what you are looking for, but I'll take a gander.
Reiteration: The saying of something again or a number of times, typically for emphasis or clarity.
Pleonasm: The use of more words than are necessary to convey meaning, either as a fault of style or for emphasis.
Recapitulation: An act or instance of summarizing and restating the main points of something.
Tautology: The saying of the same thing twice in different words, generally considered.
Oxford American College Dictionary.
Answer: If you mean for the belief exposure to not be consensual, then here are a few more.
Indoctrination: Teach (a person or group) to accept a set of beliefs uncritically.
Propagandizing: Attempt to influence (someone) with propaganda.
Proselytizing: Convert or attempt to convert (someone) from one religion, belief, or opinion to another.
Conversion: A person who has been persuaded to change their religious faith or other beliefs.
Inculcation: To instill (an attitude, idea, or habit) by persistent instruction or exposure.
Brainwashing: Making (someone) adopt radically different beliefs by using systematic and often forcible pressure.
Oxford American College Dictionary.


If I change to Ubuntu will it save the things I have on my laptop right now?

Question: I have a Windows 7 right now on my Inspiron Dell Duo. I have done this before; I changed it to Ubuntu when I first got it. I changed it back to a Windows 7 because I didn't adore it as much but I used my bro's laptop for a week which has Ubuntu and I realized I absolutely LOVE it! Now that I've had my laptop for around 8 months, I have tons of things on it (obviously) and I want to change it to Ubuntu. If I change it, will the stuff on my computer right now still be there if I change it from Windows 7 to Ubuntu?? I hope that makes sense.. Thank you!! xx
Answer: If I understand correctly, you want to install Ubuntu to your laptop and keep everything from windows?
The easiest way is to multi-boot Windows 7 and Ubuntu. Just install Ubuntu to a flash drive (or Live CD) and boot up from it. You can install it to your hard drive from there, and it gives you an option to install it next to Windows.
Optionally, you can instead use the Ubuntu Window's installer (also called 'Wubi') from the Ubuntu website. That way you can install (or uninstall) Ubuntu like you would a regular Windows program. (One limitation of the Wubi installer is that you can only give Ubuntu a max of about 30GB of space to work with. That may or may not be a problem.)
Either way, you'll end up with a laptop with both Ubuntu and Windows. Each time you boot up your computer, the first thing it will do is ask which OS you want.
If you get stuck with any of the steps, the internet has plenty of resources to guide you through the installation.
Hope this helps!
Answer: You could install Ubuntu and keep windows. This will keep your Windows and all your things in tact. Look at the below address for help.
How can I install Ubuntu without removing Windows?
If you install Ubuntu without keeping Windows then you would have to make a copy of everything you want to keep. An "external hard drive" is really good for this.
Answer: You can install Ubuntu inside Windows (It affects the disk performance though) or you can dual boot Ubuntu and Windows on the same machine (Neither way, you won't be having any data loss)
Neat step by step documentation: https://help.ubuntu.com/community/WindowsDualBoot


Should I remove vinyl flooring before laying down hardwood?

Question: I'm putting hardwood floors in my kitchen and living room, which next to each other.  The kitchen has vinyl flooring, so it is slightly higher than the living room, which has carpet on subfloor.  I want the hardwood to be at the same level in both rooms so I don't need a threshold between the rooms. Is it possible to remove the vinyl? I imagine it is glued down.
Answer: Yep, it's actually pretty easy. For the most part it'll peel up, you just need a good scraper (available at Home Depot in the flooring tools aisle) to get up the stuck down parts. Don't worry about getting all the glue up, just get the majority of the chunks up so that the floor is smooth.
Comment: And for bits that are stuck fast, a hairdryer loosens them that little bit.
Comment: Hmmm... on Particle board, that's a tough contest. On concrete I would say definitely do it, but on particle board, I'd have a hard time saying definitely. The issue that I run into a lot of times though with wood subfloors and lots of layers of flooring is moisture trapped between the layers. We had to pull up a decent chunk of subfloor in a friend's bathroom today because of the four layers of vinyl.
Comment: Iterestingly, the two flooring contractors I spoke with (well one was a carpenter), said to leave it.  Their reasoning was it would be too much effort to remove it and it could pull up parts of the subfloor (particle board in my house). I'm going to talk to at least one more flooring installer and may do the demo myself to keep down costs
Answer: Definitely remove the vinyl no matter what the subfloor is. Especially if it is on particle board. Do the job right and don't listen to so-called carpenters giving bad advice and cutting corners. Remove that particle board too and add plywood to get your heights level. You will never be disappointed doing a job the right way!! Good Luck
Answer: I'm surprised no one mentioned asbestos. Apparently it's common in old/70s vinyl flooring. Stirring it up and be a huge health risk. I plan to get take a sample and get it tested
Comment: I wouldn't call it a huge health risk. But leaving asbestos be is a good idea.
Comment: Thanks for pointing this out, Andrew. But you should make this a comment instead of an answer. Answers should only be things that address the original question.
Answer: The vinyl is very likely glued to particle board, which is attached to the subfloor (the subfloor can't be particle board because it's not a structural material). This is the way our kitchen was done.
Removing it is fairly simple; make cuts about 2' apart with a circular saw set to cut only through the particle board. You can then pull it up in sections. I would use a "remodeling" blade that is capable of cutting through any nails you might hit.
I definitely recommend to do this; getting the same height will give you a much better result.
Comment: No one believes it until they see it, but it is a 3/4" particle board subfloor, not underlayment. House built in '73.


Acoustic and classical guitars, which is which?

Question: Title says all about the question.
I have three guitars, electric and two other which i don't know if it's classical or acoustic. They both have same shape, guitars don't have cut at higher frets like electric does and also they have wide fretboards.
Answer: Classical guitars are designed to be played primarily finger-style (fingerpicking).  They generally use nylon strings which do not require near the same amount of tension as steel strings. Because of the lower tension, they do not require a truss rod to compensate for the string tension.
Steel string or folk guitars use steel strings and will have an adjustable truss rod with an adjustment screw visible from the soundhole - or under a plate in the headstock.
The neck on many classical guitars will join the body at the 12th fret whereas "steel-string" or "folk" guitars, will usually join the body at the 14th fret.
The bridge on a classical guitar will usually not have bridge pins or holes through the bridge into the body of the guitar, but will allow for the string to pass through the bridge itself (not the top of the guitar) and be tied on to the bridge with a special knot.
Guitars designed for steel strings will usually have holes through the bridge and top of the guitar where the ball at the end of the steel string will pass through and be secured against the top with removable bridge pins.  This is because the tension of steel strings could otherwise have a tendency to pull the bridge away from the top of the guitar.  Some manufacturers make bridges for steel string guitars where the string passes through a thin diameter hole that is too small to allow the ball end to pass through. But I'm guessing they might use more than just glue to fasten the bridge to the top of the guitar.
Usually the tuning pegs on a classical guitar are not actually pegs, but more like bars that the string winds onto over the top.
Tuning pegs for steel string guitars usually are perpendicular to the headstock and the string winds around them either counter clockwise or clockwise depending on which side of the headstock they are on.
The neck on a classical guitar is much wider than on a steel string guitar to allow for wider string spacing.
These clues should allow you to determine if your acoustic guitar is a classical guitar designed for nylon strings - or a steel string guitar designed for - well - steel strings.
Comment: Well... This is that I asked for and you answered very briefly and I'm thankful for that!
Comment: Cool. Glad I could help. So are your acoustics classical or steel string guitars?
Comment: One of them is classical, nylon strings and no truss rod,second one is steel 7 string, with truss rod, but it's strange, I have never seen steel string guitar with tuning pegs like nylon ones. They aren't vertical, they are horizintal and i'm just guessing how to change strings on it
Comment: @Brsgamer It's possible for a steel string to have that type peg.  But most 7 string acoustic guitars I have seen are classical.  Does your 7 string have bridge pins?  It is possible for a nylon string classical to have a truss rod.  Perhaps with 7 strings the maker thought a truss rod would be nice due to extra tension of more strings.  Or if the neck radius was thinner to make it easier to reach 7 strings the maker might have put a truss rod in because a less substantial neck might be more apt to bow.  Were there steel strings on the 7 string when you acquired it? Bridge pins?
Comment: http://imgur.com/C7Ugmk9 here's bridge.
Comment: @Brsgamer  Based on the picture you sent of the bridge, I would conclude that your guitar is a classical guitar intended to use nylon strings.  I see that it currently has steel strings.  My recommendation based on what you have shared, would be to replace the steel strings with a nylon set. Here is a link to a pictorial description of how to tie nylon strings on the type bridge you have: [Google](http://www.derek-hasted.co.uk/faqs/restring/)
Comment: If steel strings doesn't brake it, I'll replace with them, because i really like the sound.
Comment: @Brsgamer - well you have a truss rod to compensate for the tension so probably won't warp the neck.  Only other concern would be pulling the bridge up.  Steel string guitars with "pinless bridges" have a bolt or two or three that goes through the bridge and through the top and into a wooden reinforcement plate under the bridge.  So it is not only glued to the top - but bolted.  These bolts or screws are capped with wood plugs and sanded and stained to match the bridge so they are not readily apparent. But if you look close you can see little round circles on the bridge where the plugs are.
Answer: All classical guitars are acoustic. The differences come in when you consider the string material (classical acoustics usually have plastic strings in my experience) and a wider and bigger fretboard.
Comment: Often people refer to steel strings guitars as acoustic guitars or folk guitars without realizing that they are including classical guitars in their scope. I use the term steal string guitar for lack of a better term for those guitars with steel strings that are not Electric, or Resonator guitars well the list goes on... So clearly my solution lacks clarity as well, but some how it seems to solve most misunderstandings. (+1)


Nexus 10 - Android 5.0.1 OTA upgrade, "no command" and suggested steps failed

Question: I did rooting with Kingo root, and also i did factory reset. but i still can't use OTG
When I press power+voldown, boot menu starts and immediately shows "Downloading... Do not turn of target!"
then i tried Hold Power + Volume Up + Volume Down, and then i can see recovery mode, but it still not working - no command ...
I still see "System update download" , still failed.
what can i try more?
Comment: you won't get the official updates on rooted Nexus devices
Comment: get custom rom like CyanogenMod or download ROM from Google site
Comment: What recovery? Stock, CWM,TWRP? It won't install like that. A factory reset won't remove root. You'll have to flash the stock images you can download from http://developer.google.com
Comment: Thanks for all your responses ^^ I will try custom rom or factory images and let you know again. Happy New Year!!
Answer: If you are planning on installing a custom rom you need to install a recovery to flash the the ROM. TWRP is good
To get Marshmallow on the Nexus 10 Omnirom is your best bet. You'll need to flash gapps and supersu for root too.
The nexus 10 received 5.1.1 security updates until April 2016 that you can get OTA on a stock device or install manually, but manual installs will wipe the content of the device each time.
The Unified Android Toolkit is good but the information is out there on the Nexus 10 Cyanogenmod page on how to flash a custom ROM from the command line.

Nexus 10 - Android 5.0.1 OTA upgrade, “no command” and suggested steps failed


Is it haram to wear make-up?

Question: Arabic make-up is quite popular but as far as I'm concerned, Muslim women should be as humble as possible in their style. Is make-up allowed? If so, to what extend?
Comment: check the link below about makeup. http://www.youtube.com/watch?v=-HEa6rmojJ4
Answer: First of all, Islam values human tendency to beauty a lot and considers it something related to our Prima facie. It's in our nature to have tendency to beauty and to look for it.
Imam Ja'far al-Sadiq said:

(اِنَّ اللَّهَ جَمیلٌ وَ یُحِبُّ الْجَمالَ.(۹۰
God is beautiful and likes beauty.

So, wearing make-up is allowed as long as it is limited to maharem and there's no intention of a parade of beauty. Otherwise it'll provoke lust of men which is strongly proscribed by Islam. So the intention of make-up counts.
Comment: This actually *is* a hadith of rasulullah, recorded in Saheeh Muslim and Riyaad As-Saliheen. See: http://sunnah.com/riyadussaliheen/1#612
Comment: And also beauty in Islam is the beauty  of the behaviour, not of the aspect looking.
Comment: Who is Imam Sadeq? Do you mean rasulullah?
Comment: I would add that some make-ups contain unsafe and dangerous substances for our health; So not all of them are *halal*.
Comment: @ashes999: I've added a reference for more information.
Comment: The imam is Ja'farul Sidiq
Comment: Beauty is very subjective.  What is beauty according to Allah?  I personally think a person without makeup looks more beautiful.
Answer: I have no references for this, but I would say a woman is only allowed to wear make up in the presence of her husband.  You asked to what extent: the answer is, just enough to make you feel beautiful in front of your husband.  As with perfume, make up should not be worn in public.
The hadith here saying perfume of the women should not have any odour.

Pointing to the collar of his shirt al-Hasan (al-Basri) said: The perfume used by men should have an odour but no colour, and the perfume used by women should have a colour but no odour. Sa'id said: I think he said: They interpreted his tradition about perfume used by women as applying when she comes out. But when she is with her husband, she may use any perfume she wishes.

source: here
The interpretation is given by the Great Tabie (Who see Sahabah's) Al-Hasan Al-Basri.
In another hadith, Prophet Muhammad (Sallallahu Alaihi Wa -sallam) strictly prohibited the use of perfume by women which have odour or scent.

None of you women should use perfume when you are present at the isha prayer

source: here
If using perfume in prayer in the Great mosque of Nabawi with the presence of Rasul-ul-Allah was not allowed, how can it be allowed in these age of fitnah and with random persons in random areas and time?
Comment: yes the women is not allowed to wear perfume out.  because women do not need to attract men.
Comment: Please add references either to primary texts or scholarly answers.
Comment: I have heard one should present themselves before God as they would with any 'important' human. For men, it is mustahabb to wear perfume when going to the mosque; for women, it is mostly considered to be not allowed.
Comment: Beauty is very subjective. What is beauty according to Allah? I personally think a person without makeup looks more beautiful.
Answer: It is not allowed to go out in public wearing any makeup unless your face is veiled and the makeup won't be seen. It seems common these days the Muslimah will say "but I'm not wearing it to attract men" but how do you know they won't be attracted to you? (It is illogical to wear a hijab (loose flowing non see through dress covering everything except face and hands) and red lipstick!). The makeup is only allowed to be worn in front of mahrems and the husband.
https://islamqa.info/en/72390
"It should be noted that it is not permissible for a woman to wear makeup in front of non-mahram men, because she is commanded to cover her face in front of them and because wearing makeup is an adornment that leads to fitnah. If she does that and then prays, she will have the reward for her prayer but she will have the burden of sin for tabarruj (wanton display).
It says in Fataawa al-Lajnah al-Daa'imah (17/129): There is no reason why a woman should not adorn herself by wearing makeup on her face, or kohl, or doing her hair in a manner that does not make her resemble kaafir women, but it is also essential that she cover her face in front of men who are not her mahrams. End quote.
It also says (17/128): Using kohl is allowed in Islam, but it is not permissible for a woman to show any of her adornment, whether kohl or anything else, to anyone other than her husband or mahrams, because Allaah says (interpretation of the meaning):
"…and not to reveal their adornment except to their husbands…"
[al-Noor 24:31]"
Answer: Haram in Islam has a definite list as stated in Quran an none is allowed to change them. Allah prohibited touching Haram and Halal for example at the beginning of Sourah Tahrim. So wearing make up is not Haram as not mentioned so in Quran but going in order to display your finery and beauty is discouraged in Quran:

وَقَرْنَ فِي بُيُوتِكُنَّ وَلَا تَبَرَّجْنَ تَبَرُّجَ الْجَاهِلِيَّةِ
  الْأُولَىٰ ۖ وَأَقِمْنَ الصَّلَاةَ وَآتِينَ الزَّكَاةَ وَأَطِعْنَ
  اللَّهَ وَرَسُولَهُ ۚ إِنَّمَا يُرِيدُ اللَّهُ لِيُذْهِبَ عَنكُمُ
  الرِّجْسَ أَهْلَ الْبَيْتِ وَيُطَهِّرَكُمْ تَطْهِيرًا (احزاب/33)
Remain in your houses; and display not your finery, as did the pagans
  of old. And perform the prayer, and pay the alms, and obey God and His
  Messenger. People of the House, God only desires to put away from you
  abomination and to cleanse you.
Comment: @SorrelVesper Congratulate you on your courage and true view about not being ashamed of  what ALLAH says: "ALLAH is not ashamed before the truth." (Al-Ahzab 33/53). But there is a difference here: I am not ashamed of the subject at all but I'm afraid of "forging against ALLAH a lie" (Al-Anaam 6/21). Prohibition (Haram) is a special word and is of a higher degree of prohibition. Usually this kind of prohibition is stated by "Hurrimat" in Quran (e.g. An-Nisa 3/23). We should be careful while using the word. We may not assign "Haram" to whatever that is said not to be done in Quran.
Comment: It is not discouraged, It is prohibited. The two words are very different.
Comment: I have to agree with @Anwar You must be trying to soften the blow with the 'discouraged' word but you should not be ashamed of what ALLAH has prohibited. This is for our own good. We are very careful with our wording these days because people will accuse us of Anti-feminism. We do not care about such labels. Quran clearly mentions in this ayah 'Remain in your houses and display not your finery'. And today if we advocate this point, people point fingers at us for being narrow-minded. I say do not worry about such moronic taunts.
Comment: I am sorry. You are right. But you have to look at the Ahadeeth and actions of the Ummhatul Momineen. Then we will understand if its allowed for women to show their beauty to non-mehrams and go out in public with such make-up etc. and we will then see if its discouraged or forbidden.

Is it haram to wear make-up?


oracle weblogic vulnerability

Question: I searched for Oracle Web logic vulnerabilities and found this vulnerability:
Oracle WebLogic Server Cross-Site Scripting and Manipulation of Data Vulnerabilities (http://secunia.com/community/advisories/51501)
I want some sample attack scenarios to test My web site against this vulnerability, Any Help?
Answer: Well if you're the owner of the system the simplest way to confirm that your application is not vulnerable would be to ensure that the version number is higher than the affected ones.
Beyond that if you're actively looking to exploit this issue to test for its presence the text explaining the first issue is actually pretty descriptive.  To test that you'd likely need to use a proxy such as Burp or OWASP ZAP, then browse to the affected URL, look for the parameter they mention in the description and modify it to inject HTML, something like
<code>"><script>alert(1)</script><"
</code>
could be a good starting point.
For the second one unfortunately there's less details, so harder to establish. My typical approach would be to put the CVE number into your search engine of choice and see what comes up.

oracle weblogic vulnerability


How to represent Tradecraft in GUMSHOE?

Question: How can you represent good tradecraft in GUMSHOE-based games, such as Esoterrorists? That is, the techniques used in espionage, the topics or techniques (dead drops, for example).
Answer: Here are some suggestions. I'll assume a modern setting. I think The Esoterrorists is your closest fit, so let's go from there.
Remember to always think in terms of getting clues. For example, if you're wondering how to implement a Dead Drop, think how you'd use a Dead Drop to get clues. (Often, you will find that tradecraft considers techniques for passing on information, whereas, for GUMSHOE, you must consider receiving information).
With that in mind...
Make it so you use Investigative Abilities for uncovering clues, General Abilities for other stuff. This sounds obvious, but the problem is: many tradecraft skills, such as Shadowing (Trail of Cthulhu) and Surveillance (Esoterrorists), are currently general abilities. Since they will be used mainly for getting clues, try making them into Investigative Abilities.
So, in your Dead Drop example, we could upgrade Stealth to an Investigative Ability, then spend a point to get the clue from the dead drop. Similarly, if tailing someone in a car, we might upgrade Driving to an Investigative Ability, then spend a point to find out where the car is going.
(Note: you can, in any GUMSHOE system, spend a point of a General Ability to get a clue. However, if the abilities are primarily used as Investigative Abilities, we should reclassify them.)
Use existing abilities where possible, even if you need to import them from another system. For example, Locksmith is a Trail of Cthulhu ability, but it's not usually used in Esoterrorists. However, it's great for spy stuff. So import it into your game.
So, to take an example of searching someone's apartment for a clue: you spend Locksmith to get the clue from their apartment.
Use Interpersonal abilities for all aspects of Tradecraft that involve interacting with people. For example, to recruit someone under a false flag, you might use Reassurance or Intimidation (depending on how you want to do it).
Split abilities if you need to. An unwritten rule of GUMSHOE is that, when you need more specialised skills, you can split them. So, for example, you could split Electronic Surveillance into Bugging and Radio Surveillance.
Add new abilities if you're covering new areas, but keep them close to existing abilities. For example, you might want a Seduction ability for honey traps. This doesn't really play a part in Esoterrorists or Trail, but it'd fit nicely in a spy game. So create one, but make it work like Reassurance or Intimidation.
Overall, I think you've got most of the tools you need, especially if you scour the different systems. Where possible, use what's there; where it's not, stretch the existing system.
Some more specific examples, using the above techniques. All of these are either Investigative Abilities or General Abilities used as Investigative Abilities: that is, for all of them, spend a point rather than making a roll.

For a Brush Pass, use Stealth as an Investigative Ability.
For a Dead Drop, import Conceal from Trail of Cthulhu, expanding its remit slightly (so that it's not just about keeping things concealed, but finding good hiding places).
For a Car Toss, use either Stealth or Drive as an Investigative Ability.

And so on.
By the way, I showed this question to Simon (who publishes GUMSHOE) last night, and he said that Night's Black Agents will answer most of these questions when it's released. So there you go.
Answer: Much of tradecraft isn't easily simulated by a roll, so much as player knowledge. Clandestine HUMINT techniques are a function less of unique skills and more a function of knowledge of how to apply said skills.
For example, in Esoterrorists, we have the Cryptography skill which covers many of the crypto functions of tradecraft, and should be extended to preparing messages for passage. Especially as the skill, in a forensic sense, is more cryptanalysis than cryptography, letting players know that it is allowed in both senses seems workable.
Evidence collection, with training in tradecraft, also suggests finding evidence of dead drops, and other forensic counter-intelligence investigations. Photography used to be vital, as many techniques aren't good at passing bulky papers, requiring that written notes be turned into microfiche.
Streetwise could be used to spot tails, perhaps even to do a brush-pass. And so on and so forth. While there could be a "tradecraft" skill, the skill would be more of a planning nature as the actual execution of these practices are well covered under other skills.
If your players are unfamiliar with intelligence and counter-intelligence, a cheat-sheet or link to Wikipedia would be appropriate, so they know what actions are feasible in the game.
Answer: Night's Black Agents devotes several pages to discussing what skills are involved in various tradecraft techniques.
Answer: I have to agree with @BrianBallsunStanton, tradecraft in general might be an acceptable skill for some games but not GUMSHOE which has very fine grained ones.  I agree with his take that it's mostly covered and to "tell them what they can do" - and you may want to flesh out the skills list in weak areas important to you.
In fact, it seems like the biggest gap is that the skills as described are almost completely reactive. In the default investigative paradigm of the game the skills are usually used to "find a clue" or "get him to tell you" not "plant false info" or "turn an asset."  But that I think is as simple as resetting expectations, and between all the interpersonal skills and Crypto I think the vast majority of tradecraft is already represented.
If you want to track cover identities and safe houses and that kind of stuff, then I think like in the "relationship with organizations" question you'd add a separate "skill" (really just a point pool) called "Cover" that would reflect the remaining utility of the PCs' resources in that vein.
Comment: Hm?  What's the problem with this answer?

How to represent Tradecraft in GUMSHOE?


Does Raspberry Pi runs Minecraft and Netbeans 7.2?

Question: I have a computer with 512MB of RAM Memory, CPU Intel Celeron 1.60GHz and a 80GB HD. After the new Minecraft update to 1.3.X, Minecraft don't run on my computer any more even on Windows XP and Lubuntu (LXDE/Openbox) and Netbeans 7.2 freezes all the time. So would like to know if Raspberry Pi runs this softwares correctly? Before I buy one.
Comment: Note: As of Feb 2013, there is a Raspberry Pi edition of Minecraft, as per this answer below: http://raspberrypi.stackexchange.com/a/5066/68
Comment: First: Just get the newest raspian. Mincraft included. Second: Why do you want that? I'm not shure if there is a ARM version of Netbeans anyway.
Answer: As you can see on Raspberry Pi FAQ, the real performance of the Raspberry Pi is something like 300 MHz Pentium 2. There is 256 MB RAM installated on both model A and B. Try to compare this parameters to the parameters of your computer.
The reason that Raspberry Pi could smoothly play BlueRay quality videos is in used Videocore 4 GPU which provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode. GPU is capable decoding a video encoded by H.264 codec at 40MBits/s.
But overall computing performance is much lower than performance of hardware you have. Raspberry Pi is aimed to completely different usage. Don't buy it if you want to run software that has sometimes problems with performance on 10 times more powerfull hardware.
Comment: New models have 512 MB.  Still very little for an IDE.
Comment: You both gave me good answers but I have to choose one as the correct.
Comment: You will need to use a **Soft-float** operating system.
Answer: The system requirements for NetBeans state that it needs minimum of 512 MB of memory to run. Since the Raspberry Pi only has 256 MB of RAM, I would have to guess that there is very little chance of getting Netbeans to run.  Especially considering that to run a graphical desktop, you should probably be giving the video processor 32 MB of that memory leaving you with somewhere around 224 MB of RAM available to the system. Perhaps an old Refurb IBM Desktop would better service your needs.
Answer: There is now an edition of Minecraft specifically for the Raspberry Pi. It's called Minecraft: Pi Edition. I know this only answers half the question, but I figured I'd leave the information here for future reference.
Answer: First: Just get the newest Raspbian. Minecraft included.
Second: Why do you want that? I'm not sure if there is a ARM version of Netbeans anyway.


Measurable language which is not $\omega$-regular

Question: Let $\Sigma$ be a finite alphabet and let $\Sigma^\omega$ be the set of all infinite words over $\Sigma$. Consider
$$
  d(x,y):=2^{-\min(n \in \Bbb N_0:x_n\neq y_n)}
$$
to be the metric on $\Sigma^\omega$ which makes the latter being the Cantor space. Denote by $\mathscr B(\Sigma^\omega)$ the Borel $\sigma$-algebra of this space, and let's call its elements measurable languages. It follows from Proposition 6 here that any $\omega$-regular language is measurable. I am looking for an example of a measurable language which is not $\omega$-regular, so any hints are appreciated.
Answer: A simple class of examples can be found by considering singleton languages $\{w\}$. These are measurable (Let $C_n(w)$ be the set of words agreeing with $w$ up to the $n$-th letter, then $\{w\}$ is the intersection of all $C_n(w)$). However, unless $w$ is eventually periodic, the language is not $\omega$-regular.
For a concrete example, consider the word $w=ababbabbba\dots$. If $w$ is accepted by a nondeterministic Büchi automaton $A$ with $k$ states, then while parsing the $n$-th block of $b$s, with $n>k$, $A$ needs to visit some state twice, so we can construct another word accepted by $A$ by pumping this block suitably. Therefore no automaton recognizes $\{w\}$.
Comment: One can also obtain non-regular languages at arbitrary Borel levels, by adding a nonperiodic $w$ to a regular language $L$ (with $w\notin L$). The resulting language $L'=L\cup\{w\}$ will always be non-regular, because otherwie $L'\setminus L=\{w\}$ would also be regular.
Comment: That's a very insightful answer, thank you very much. Can you suggest many any "canonical" references dealing with Borel structures over $\Sigma^\omega$? I've only seen the paper I cited in OP, but it only touches upon a few number of concepts. Clearly, $\Sigma^\omega$ is just a Cantor space, but I'm interested how the topological/measure-theoretical properties of it are related to those of regularity etc. For example, if I'm not mistaken, regular languages (embedded in $\Sigma^\omega$) are precisely open sets?
Comment: Not sure about "canonical", but two starting points would be (1) Halpern and Schneider, Defining Liveness (contains the characterization safety = closed and liveness = dense), and (2) numerous papers by Alain Finkel, in particular "Borel Hierarchy and Omega Context Free Languages".
Comment: Cool, I'll take a look into those sources - perhaps references there will also steer me. Btw, could you please use this `@username` stuff? Otherwise it does not appear in the inbox, I passed by your comment by coincidence
Comment: Nitpick: it's Bowen Alpern and Fred Schneider. Joseph Halpern did a lot of great things but didn't contribute to this paper.


Does Pure Land Buddhism ever have a Buddha other than Amitābha as the object of devotion?

Question: Does Pure Land Buddhism ever have a Buddha other than Amitābha as the object of devotion? Or is Pure Land Buddhism by definition a devotion to Amitābha and an aspiration to be reborn in his pure land? I'm aware there are a lot of other Buddhas so I just wondered if they were ever the focus of this tradition.
Comment: Any specific type of Pure Land, or any Buddhism with Pure Land elements? I'm reading up on Shin right now, they seem to only care about Amitabha. Chan, Vajrayana included Pure Land sutras & elements as part of a larger system. So Bhaisajyaguru (Medicine Buddha) was/is venerate and presides over a pure land that you can be reborn in to. In Vajrayana & Chan there are so many Buddha's and Bodhisattvas all competing for mind share, these Buddha with Pure Lands didn't get as much specific attention.
Answer: Amitābha Buddha has two attendant bodhisattvas: Avalokiteśvara and  Mahāsthāmaprāpta and they all are present in meditations based on visualisation used in the Pure Land Buddhism (as well as in Vajrayana).
Answer: Yes, there is other Pure Land in Buddhism other than Amitabha Buddha's. It is called the Pure Land of Lapis Lazuli of the East. The Buddha that resides there is called Bhaisajyaguru Buddha or Medicine Master Buddha of Vaidurya Light. In order to achieve rebirth there, one must practice the recitation of the Buddha's name. For the rest of one's life.
Answer: The primary object of devotion in Pureland Buddhism is Amitabha, but there is secondary devotion to some other figures. I'm not sure if secondary devotion to other Buddhas is common, but Avalokitesvara is usually held in high esteem in Pureland.
Comment: @Crab They're related sometimes in stories, but I've never heard anything like that.
Comment: +1 thank you. However isn't Avalokitesvara an emanation of Amitabha?
Comment: Says here on this probably unauthorative site that Avalokiteshvara is the earthly manifestation of Amitabha Buddha http://buddhism.about.com/od/thetriyaka/a/avalokiteshvara.htm
Comment: That isn't correct. Avalokiteshvara is the boddhisatva Guanyin https://en.wikipedia.org/wiki/Guanyin
Answer: In Jodo Shu and Jodo Shinshu, Amitabha Buddha is the sole object of devotion, because to be devoted to Amitabha Buddha is seen to be devoted to all the Buddhas, in spirit and practice. Reciting Nembutsu is seen as fulfilling the aspirations of all the Buddhas, including Shakayamuni and Avalokitesvara.
From "What Kind of Buddha Is Amitabha?", A Discourse by Dharma Master Huijing, Xiamen, China; October 2006:

Moreover, to recite the name of a single Buddha, Namo Amitabha Buddha, is equivalent to reciting the names of all Buddhas. When we recite Amitabha's name, the Buddhas of the ten directions will come to praise, protect and encourage us. So there is great wisdom in choosing to practice this teaching.
After we learn this practice, there is no further need to recite the names of Bodhisattvas Avalokitesvara and Mahasthamaprapta. If we only recited Amitabha Buddha's name, Avalokitesvara and Mahasthamaprapta would happily become our friends, even brothers. They will safeguard us, the way a shadow follows the form that cast it. For the name we recite is the name of the one who sits on top of their heads.
We should realize that Bodhisattva Avalokitesvara's goal is to guide suffering beings to recite the name of Amitabha Buddha, who will deliver them to the Pure Land. Otherwise, Avalokitesvara would be saying, "How tired I am! You are still reincarnating and suffering. Lifetime after lifetime, again and again, I still have to save you from pain and peril. But if you recite 'Namo Amitabha Buddha' this very lifetime, I can relax!" That's the aim of Bodhisattva Avalokitesvara.

Individuals in other Pureland sects throughout East Asia revere other Buddhas. But, if you notice, my quote above is taken from a modern day Chinese master. This is because some Chinese Pureland masters reference the works of Master Shandao, the Chinese Master whose work was translated into Japanese and inspired the Jodo Shu and Jodo Shinshu sects (he taught exclusive Amida recitation). Some masters are making an effort to return this teaching and legacy to places like China and Taiwan.
In the same essay I quoted above, you can find this idea:

...So our school is not some Japanese Pure Land school. Our school of the Fundamental Vow teaches the 18th Vow of Amitabha Buddha. What does the 18th Vow say? It speaks only of Amitabha-recitation. Master Shandao said, "Shakyamuni Buddha's underlying wish is none other than for beings to recite the name of Amitabha single-mindedly and exclusively." The 18th Vow is called the Fundamental Vow. Thus "Amitabha-recitation, according to the Fundamental Vow" was taught and transmitted by Master Shandao.
What is the purpose of the Fundamental Vow? And what is the reason for Amitabha's attainment of Buddhahood? The goal is that all sentient beings can be reborn in the Land of Bliss merely by reciting Amitabha's name. Therefore "Shakyamuni Buddha's underlying wish is none other than for beings to recite the name of Amitabha exclusively." Recitation of Amitabha Buddha's Great Name of a Myriad Virtues is specified in the Fundamental Vow; it is also the only practice mentioned there.

(Source URL: http://www.pureland-buddhism.org/PureLand/Teachings/What%20Kind.aspx)
So, it all depends on what practice someone chooses.
Answer: Short answer, no. Although we revere Sakyamuni, he is not the focus of Pureland. However, the devotion to bodhisattvas is something else. Mainly, there is Kuan Shih Yin Pusa, Ta Shih Chi Pusa, and the rest of the "ocean-wide lotus-pond assembly" of bodhisattvas in the Pureland.
While there are other Buddhas in other pure lands, and people have paid reverence to them, that is not the definition of what we call Pureland Buddhism. Rather, that would be a secondary practice. Or it might even be part of Vajrayana Buddhism.


Can a vowel and a consonant be allophones of the same phoneme?

Question: Are there languages where a vowel and a consonant can be allophones of the same phoneme?
Comment: The English consonant phoneme /h/ has only voiceless vowels as allophones. The English phoneme /r/ includes many vowels and many consonants among its allophones, in the various dialects of English spoken around the world.
Answer: I think this question may be trickier to answer than you realize--it largely depends on your definition of vowel and consonant.
If you take a structural phonological approach to defining those terms (i.e., if whether something is a vowel or a consonant depends on where it occurs in the syllable), then they are by definition in complementary distribution, so there's no way to prove that any vowel and any consonant aren't allophones of the same phoneme. We may say that [j] and [l] must be realizations of different phonemes, because we have minimal pairs like yes/less.  Similarly, [oʊ] and [i] must be realizations of different phonemes because we have minimal pairs like boat/beat. But there can't be a minimal pair that contrasts in the inclusion of a vowel vs. the inclusion of a consonant in the same syllabic slot. Pairs like yon/eon and fro/furrow don't count, because in such cases both the segmental makeup and the syllabic structure is varying. (Note that the same is true for the French example in @cyco130's answer.) In such a model, one might look to distinctive features as a guide for identifying consonant vowel pairs that might be considered allophonic pairs. In particular, one might consider approximant/vowel pairs in French, English, etc. (of the type that @cyco130 describes) to be allophone pairs by virtue of the fact that their "features" (other than +/-syllabic) are the same. Of course this kind of criterion is entirely dependent on the feature set you use!
If you have other criteria for vowel vs. consonant, like 'vowels must be voiced' and 'all fricatives are consonants' (regardless of whether they are syllabic or not), then it may be possible to find some other types of cases that would qualify. For example, it is well-known that in continuous speech in Japanese high vowels often get devoiced after voiceless consonants. It is even common for the vowel to "disappear" altogether and be replaced by a lengthened version of the consonant before it, effectively being realized as a fricative*.
<code>/de.su/-->[de.sː]
/ki.ta/-->[kç.ta]
</code>
Depending on how you analyze such cases, you could argue that these surface fricatives in Japanese are allophones of the underlying high vowels.
Note that there is actually an articulatory and acoustic difference between the voiceless vowel [i̥] and the voiceless fricative [ç]. What is often described as the former is more accurately described as the latter. In the case of [i̥], the main constriction (and therefore the source of turbulent noise) is in the glottis; in [ç] it's between the tongue and the hard palate. I would argue that some realizations of /h/ in English are not voiceless vowels (as @jlawler claimed) but rather fricatives. Try pronouncing the beginning of the word huge and compare that sound to a whispered /i/ vowel. They are probably produced differently and sound different. But the /h/ in hot is pretty much realized the same as a whispered /a/ vowel. So one could make the argument that some allophones of /h/ are voiceless vowels and others (namely those before /i/ and /j/) are voiceless fricatives!
Comment: @GraphicsResearch As I said, it depends entirely on your feature set and your model. Note that in the Japanese example I give two cases of syllabic fricatives.
Comment: @GraphicsResearch no need to tag the person whose post you are commenting on--the person gets notified automatically. I think that's why you couldn't tag me.
Comment: Not all consonants need be `-syllabic`, and not all languages restrict `+syllabic` to be vowels only, or even `+sonorant`.  While most dialects of English support nasals as syllabic, some Indonesian languages allow fricatives and stops to be syllabic.  I remember in particular one example word: `/ptk/`.  I'm pretty certain an example must exist.
Comment: Indeed, and I agree.  I consider the feature set to be a property of the language (or rather, of the phonology linguists use to describe it).  Thus, my point is that, with all the world's languages, I'm _certain_ an example exists that everyone could agree on.  Oddly, I can't tag you.  Hmmm.
Answer: Of the top of my head, French comes close. According to Wikipedia "the approximants [j], [ɥ] and [w] correspond to /i/, /y/ and /u/ respectively. While there are a few minimal pairs (such as loua [lu.a] 's/he rented' and loi [lwa] 'law'), there are many cases where there is free variation".
Also many linguists consider Proto-Indo-European *i and *u as vocalic allophones of *y and *w (or vice versa). Some people also suggest that PIE laryngeals had vocalic allophones.
I'd guess approximant/vowel allophones not to be uncommon cross-linguistically.
Answer: I suggest we leave proto-Indo-European out of this. You cannot really use hypothetical reconstructed languages to illustrate points of phonology and phonetics.
In Latin qui and cui are a minimal pair; the former was presumably /kwi/, the latter /kui/ or possibly /kuj/. My recollection is that the poets scan the latter both as two syllables and as one.
French loua /lua/ and loi /lwa/ are indeed a minimal pair, but only in lento speech. At normal speed they are both realised as [lwa].
jlawler's remark about English /r/ is interesting. But I am not sure whether it is meaningful to analyse Southern British English "fear" phonologically as /fi:r/ rather than as /fiə/; in the latter case "r" would be purely orthographic/historic for the phoneme /ə/.
Answer: In Standard German, the R behaves like this.
Prevocalic /r/ is pronounced [ʁ] or [ʀ], but postvocalic /r/ is pronounced [ɐ]. This is not merely an orthographic convention: Adding a suffix can produce a new syllable and turn [ɐ] into [ʁ].
Examples:
"Rad" (wheel): [ʁat]
"Bär" (bear): [beɐ]
"Bären" (bears): [be.ʁən]
"Bauer" (farmer): [baʊɐ]
"Bäuerin" (female farmer): [bɔʊə.ʁɪn]
Disclaimer: I'm not a linguist, so the transcription may not be 100% accurate.
Comment: I understand your point. I wonder whether the [ɐ] in [beɐ] is really a vowel, or a semivocalic offglide.
Answer: Think of the word 'little' in Southern English (for example the speech of Londoners). Both l's are regarded by speakers as the same phoneme however the first is a consonant and the second is a back vowel.
Compare that with Northern English or American English where both are consonants albeit, at least in Northern English, the second is syllabic.


What is the correct kavanah when going to war?

Question: I am specifically talking about going to war that is a mitzvah such as the wars fought while conquering Eretz Yisroel in the beginning of the Neviim and the mitzvah we have and will fulfill of destroying the entire nation of Amalek.
I have not seen anything written on what the Torah perspective is for the soldier going and killing people when done as a mitzvah. (Are you supposed to be besimcha? Are you supposed to have a part of you not like what you are doing?)
As always sources for ideas will be most appreciated.
Comment: This is a very complicated and important question which delves into the fundamental nature of the laws of Torah and their meaning to us in relation to terms such as morality, ethics and the Good.
Comment: Related: http://judaism.stackexchange.com/q/17491/1569
Comment: http://judaism.stackexchange.com/questions/21983/what-kavanos-should-one-have-when-sharpening-a-challa-knife-erev-shabbos#comment49950_21983
Answer: See Rambam Laws of Kings and Wars chapter 7 Halacha 15:
"Once a soldier enters the throes of battle, he should rely on the Hope of Israel and their Savior in times of need. He should realize that he is fighting for the sake of the oneness of God's Name. Therefore, he should place his soul in his hand and not show fright or fear.He should not worry about his wife or children. On the contrary, he should wipe their memory from his heart, removing all thoughts from his mind except the war.Anyone who begins to feel anxious and worry in the midst of battle to the point where he frightens himself violates a negative commandment, as it is written (Deuteronomy 20:3): 'Do not be faint-hearted. Do not be afraid. Do not panic and do not break ranks before them.'Furthermore, he is responsible for the blood of the entire Jewish nation. If he is not valiant, if he does not wage war with all his heart and soul, it is considered as if he shed the blood of the entire people, as ibid. 20:8 states: 'Let him go home, lest he demoralize the hearts of his brethren like his own.' Similarly, the prophetic tradition explicitly states: 'Cursed be he who does God's work deceitfully. Cursed be he who withholds his sword from blood.' Jeremiah 48:10In contrast, anyone who fights with his entire heart, without fear, with the intention of sanctifying God's name alone, can be assured that he will find no harm, nor will bad overtake him. He will be granted a proper family in Israel and gather merit for himself and his children forever. He will also merit eternal life in the world to come as I Samuel 25:28-29 states: 'God will certainly make my lord a faithful house, for my lord fights the wars of God and evil will not be found with you... and my lord's soul will be bound in a bond of life with God.'"
Comment: "with the intention of sanctifying God's name alone" This is a good start. Everything else the Rambam is stating can be understood as how the soldier needs to ACT, but the quoted sentence starts speaking to the thoughts and intentions of the soldier.


Does the amount of fuel in the tank matter?

Question: As long as there is some fuel in the tank, does the fuel level matter? In other words, is it advisable to make sure the tank is mostly full most of the time, or is this just silly? In other words, are there valid reasons why you should avoid running on an almost empty tank (other than the risk of actually running empty)?
Comment: How old's your car?  Mine's got the fuel pump at the engine, not the tank.
Answer: Both previous posts are pretty good.  I'll add a few more considerations though.

On a low tank, during hard cornering, some cars will uncover the fuel pump pickup and starve for fuel.
There's been some discussion for years now about keeping 1/4 tank as your minimum as the fuel provides cooling for the fuel pump.  Some people argue that additional cooling will extend the life of the pump.  My take on it is that indeed it does, but that it doesn't matter as the pump won't overheat either way (OEM fuel pump failures are exceedingly rare nowadays, nearly all fuel pump replacements that I've seen done turned out to not solve the problem they were having...).
Any floating debris will stay safely above the pump intake if the tank level is kept up.  Run it down far enough and that stuff will get sucked in and contribute to either clogging the filter eventually, or even physical damage.
Comment: Side point on the "keep a minimum of 1/4 tank": it's actually handy for *spouse* cooling as well.  Ever been late to an appointment with your loving significant other and had to explain that you're nearly out of gas...?
Comment: It should be noted that any "floating debris" are not going to be prevented from entering the pump simply because you have some gas in the tank. The first time you turn a corner or hit a bump, the tank will be thoroughly mixed, giving even floating debris a chance at the pump intake.
Comment: Debris is a winning point: there will be gunk in the tank and a super low level in the tank increases the probability of injesting that gook significantly.
Comment: @Fake Name, actually you won't be mixed in a single turn.  Mixing will occur all of the time.  The volume in the tank reduces the density of the gunk in terms of stuff per unit fuel volume.  You are correct that there isn't a magic spell, fuel or not, that will prevent all injestion ever.
Answer: There is an unexpected effect to running with a full tank all of the time: fuel is heavy.  The actual weight per gallon depends on temperature (and thus on density) but it's on the order of six pounds per gallon (or about .7 kg per liter, if you like doing all your math in base 10...).
Obviously, the total weight depends on your vehicle's tank.  In my car, driving full all of the time would be an additional 90 pounds.  That has a measurable effect on mileage, especially in the in-town lowish speed driving that I'm often doing.
I generally fill up, run it down to about 1/4 tank, fill and repeat.  On average, I see better mileage than "full all the time."
As Gabriel notes, however, weather can trump mileage.
Comment: @Drawninpictures - Again, if you'd like to take this up in chat, I'd be more than happy to oblige.
Answer: Knowing that gasoline does not freeze (Ok, it will start freezing at -180 degrees, but this is more than you or your car can tolerate) but that a small amount of water can accumulate in yout tank over time.
So, in cold winter weather condition, like here in Canada, if you have a low level in your tank, that accumulated water could freeze and cause some issues, like blocking your fuel pump or hoses.
Comment: Gasoline actually freezes (or a firm facsimile there of) at around -40 to -50C according to [this source](http://van.physics.illinois.edu/qa/listing.php?id=2479). Check the follow-up question at the bottom of the page. There are a lot of opinions out there, but believe a physics page might be correct.
Comment: The main components of gasoline are isooctane (melts at −107°C) toluene (melts at −95°C) MTBE (melts at −109°C), xylene (melts at −47.4 °C) and butane (melts at −134°C). So at −180°C it will be already rock-solid.
Comment: You're right: condensation in the tank can be a hassle well before freezing, especially if you're running your tank at a low level all of the time.
Answer: If you are planning to let your car sit for a while, it also may be adavisable to have a full tank. Less air in the tank means less corrosion of the tank, if you have a metal one.
Comment: But if you are planning to let your car sit for a LONG while, I'd drain the tank completely.
Comment: Most DOT approved tanks are platic.. For many reasons
Comment: Less condensation of water with a full tank also.
Comment: Not all tanks are made out of plastic. For instance Marine tanks are often made out of fiberglass and that fiberglass reacts badly with the ethanol applied to petrol.
Answer: I always let my fuel level reach near empty. Other than the cool effect on the pump, I see no advantage of not letting it get below 1/4 tank. Water is heavier than gas, so if there is any water in the tank it will be picked up by the pump first. Same goes for any debris in the tank. The pump is also situated so that on cornering the fuel pump will not be deprived. I will admit that I have run out of gas a number of times, not for a few years now, so feel free to discount my comments.
Comment: In Tank Electric fuel pumps can run hot on low fuel, shortens the life of the pump. I would not run this type of fuel system low on fuel as a habit.
Answer: He is correct! The actual pump is inside a canister and unless the tank is bone dry, the pump is ALWAYS submersed in fuel ( even when cornering hard). if this was not the case, the vehicle would stutter and hiccup due to air in the line. Anyone who has ever had this happen, knows it does this only when you completely run out of gas.
Just look at the design for yourself and use common sense instead of listening to opinion and hearsay.
Answer: I also would add that, besides avoiding problems with running always with less than 1/4 (probably, a few times would be alright), you could also avoid being without gas if you are in a jam or need to go to a place which is far than you expect, like giving a ride, and you don't have time to fill the tank or there is no gas station near.
Anyway, I always prefer to be safe than sorry. And I guess there are few reasons, other than monetary, not to keep it with at least 1/4 filled.
Comment: Monetary?  Since the price of gas is constantly increasing, it's better monetarily to fill it up now while it's cheaper.
Comment: @endolith I really see no difference, since really quick you'll have to pay the new price. Unless is up to 10-20% a week. And also, you're contextualizing that question to US residents and also to an specific period of time where the gas is rising a lot, which might me biased and not generic enough to this question.
Comment: Nothing like going to a station with your car on "E" and finding that the gas door release has broken and there's no way to get gas in the car.  :-)
Comment: The "monetary" issue is an interesting one. Consider that if everyone keeps a full tank rather than a ¼ full tank, the petroleum industry gets four times as much money sooner -- and they don't have to build four times as much storage! So help the oil barons out and fill your tank! :-)
Comment: @BrianKnoblauch many cars have an emergency release pull cord in the trunk  somewhere, behind a panel. I suggest everyone should familiarize themselves with its location because the gas doors do fail to open normally from time to time!
Answer: It doesn't matter how low your fuel level is, the fuel pump will always be submerged in fuel, the pump actually sits inside a well that is full of fuel, its like this on every car that has an internally mounted pump, otherwise the mass would be exposed to oxygen and a spark can ignite the tank vapors and boom. --- former UTI graduate.
Comment: As Brian's top answer says, it is on cornering that this becomes an issue.
Answer: so many things to say on the matter!On newer cars with the fuel pump in the tank the gasoline tends to cool the pump extending its useable life. Next the engine is designed to send an excess amount of fuel forward to the engine and a line returns back to the tank what is not needed. this however allows the fuel to gain heat and this causes the fuel to expand as well as reduce efficiency costing you in fuel milage. Lastly the bottom of the tank can and does accumulate crud over time and the lower the tank the higher the odds are of sucking up larger amounts of it.
Answer: Water is heavier than gas and will stay at the bottom of the tank. True, after a little driving the water will mix somewhat with the gas so your going to get a little water sucked up anyway. I like to run as low as I dare so as to get as much water out as posible. A small amount of water running through the engine won't hurt, in fact in some cases a little water is good.(ever hear of water injection) Debrie I don't worry about but I do worry about the extra water produced by the use of ethanol. Best to run this water out a little at a time rather than to let it sit and destroy your tank.
Comment: Wow ... Cannot count on how many levels running your fuel tank empty is bad. There are other ways to get water out of you tank than letting the engine suck it up. If you have that much water in your tank you will stop your engine dead when it sucks it up. If you have an older vehicle and run it dry, you will probably clog the in-tank filter with any sediments. A lot of cars use the gas itself to cool the pump. When you run it dry, you can overheat your pump, shortening the life span of the pump. Just really is a bad idea. Try to keep the tank at least half full to avoid problems.
Comment: If anything, the use of ethanol will prevent the water from accumulating in your tank. Ethanol will mix with water, unlike gas.
Comment: There is also this wonderful substance called dry-gas which is additional ethanol that you can put into your tank it's mostly used in the winter time but you can use it all the time.
Answer: yes it does matter
the common reasons

making hard turns can slosh all the fuel to one side in an empty tank and the fuel pickup will not be in fuel causing your car to sputter as if it's out of gas and potentially stall.
low fuel means certain smog tests can fail
low fuel means you have a higher risk of sucking up floating debris and clogging a fuel filter.
in gravity fed systems it could mean you will have low fuel pressure especially if anything is partly clogged.

the uncommon reasons

low fuel is less weight and less weight means faster 0-60 times and better cornering
low fuel adds to the better cornering because there is less sloshing around potentially causing the car to slide
low fuel adds to fuel economy due to less weight
low fuel reduces tire wear due to less weight. in fact you could say it reduces many different types of wear including brakes clutch bearings engine and many others due to less weight.
consistently low or high fuel leads to more frequent re fuelings which can increase wear on certain parts like your starter
consistently low or high fuel can lead to having your credit card stolen more often or extra refund fraud from gas stations when they do not automatically refund you the unused fuel.
low fuel can increase fuel tank damage due to expansion and contraction forces from hot and cold evaporated fuel inside the tank
Comment: If you are doing enought high power cornering to worry about gas tank slosh as a performance issue then you would have already invested in a gas tank with baffles. The last 3 bullets are strictly hyperbole.
Comment: Do you also fill your windshield washer reservoir a pint at a time to make sure your mileage isn't affected?
Answer: We read in the basic schooling and in aviation education, that always keep the tank full to avoid accumulation of fuel fumes specially in hot weathers.
 low fuel can increase fuel tank damage due to expansion and contraction forces from hot and cold evaporated fuel inside the tank.
Weight saving and wear n tear of tires are secondary because safety of life would have more  priority
Answer: Moisture can collect on the inside wall of the tank. When temperatures outside hover around the freezing point of water the moisture turns to ice which falls off of the wall and sinks to the bottom of the tank where it can clog the fuel pump or gas line.
In older days this problem needed gas line antifreeze which was added to the fuel. Gas anti freeze is simple alcohol which dissolved the water before it froze. Today, most fuel has alcohol added at the pump, hence no need for antifreeze.


Why is the submediant chord in a D Dorian mode a Bm7b5?

Question: Why is the submediant chord in a D Dorian mode a Bm7b5? I thought a Dorian mode has only flatted 3 and 7 compared with a major scale. I am trying to learn about harmonizing church modes and need to learn how to harmonize the other church modes. Are there any rules I did not read? Pretty confused.
Answer: I find it easier to relate back to what I call the 'parent scale or key' with modes. So here, we have D Dorian mode, translating back to parent key C major.
That gives this mode all the 'white keys' on a piano - naturals - no # or b. Thus the 4 notes using B as a bass/base are B, D, F, A. This is Bm7b5.
The confusion comes, I think, from the fact that Dorian does have a b3 and b7 in comparison to the major scale notes, but that's a red herring. This chord is based on B, not D, and if it's built up in thirds, there is a minor third (B-D), then another m3 (D-F). Putting two m3s together produces a b5 (B-F). The 7th part is going to be B-A.
Harmonising any mode is so much clearer when it's taken back to parent key. Because the harmonies produced there have probably been met many times previously. Why re-learn something we already know?
Answer: The notes in D Dorian are D E F G A B C.    If you build a 'pile of 3rds' on the 6th note in that list, you get B D F A.   Which can be called Bm7b5.
Now, be sure to keep your head in modal mode, lest you're tempted to follow it with E7, Am7, D7, G7, C  :-)
Answer: Perhaps I've misunderstood the question, because it seems a little bit obvious to me.  The fifth tone of the submediant is the third tone of the tonic, and you've already pointed out that the third tone of the tonic is flatted.  So, yes, the fifth tone of the submediant would also be flatted because it's the same note!
Please tell me what I've misunderstood in your question so I can give a better answer!
Answer: This might not be the most scientific answer, but to make this easier, when  I get confused with modes, I try to think in terms of scales. D Dorian would be the ii in the C major scale. The B chord in this scale is Bm7b5 (B D F A).
Or else, I would see the notes that are in the D Dorian scale: D E F G A B C. To form a chord on B using these notes, you'd get the Bm7b5.
Also, you seem a bit confused about the Dorian scale. You mentioned a Dorian scale is only flatted 3 and 7. This is true. Just start from D: D, E, F(b3), G, A, B, C(b7), D. Νοw again, if you use these notes to build a chord on B, you'll get the Bm7b5 chord. Τhe flatted 3rd and 7th apply only in relation with the root (in this case D); they don't apply to each note of the scale.