Why are Thalia, Jason, Nico, and Hazel allowed to swim?

Question: Recently, as I reread Percy Jackson and the Lightning Thief (for the billionth time), something occurred to me. Percy Jackson is clearly banned from flying because of the rivalry between Zeus and Poseidon, so why are Jason, Thalia, Nico, and Hazel allowed to swim? Percy was threatened and nearly killed when he went into the Underworld and flew on an airplane, so why are the other children of "The Big Three" allowed to swim?
Comment: Maybe Poseidon isn't as mean as Zeus.
Comment: Maybe, doesn't seem to make sense, though, because in actual Greek Mythology Poseidon is the mean one.
Comment: Well, if you're looking for in-universe answers, @Jack, then you don't look at the original myths. First you look at what the author wrote.
Answer: I think it is partly as in @Adamant's comment in that Poseidon is shown as a nicer god. Zeus is shown as immensely proud and quite quick to anger. This means he dislikes Percy Jackson flying as an infringement on his territory. Hades trying them was more that he thought they had taken the Helm of invisibility rather than Percy being Poseidon's son. Poseidon is shown in the books as a laid back and easy going guy which suggests he wouldn't just kill a demigod for entering the sea.
Secondly, I am not certain but I think Zeus got more laid back about the killing Poseidon's children thing after the Big Three  prophecy was sorted. Before then Nico was safe in the Lotus Hotel or hanging out in the Labyrinth and the Underworld where he probably wouldn't be swimming. Thalia was either already bring hunted by Hades or a tree or Huntress for most of that time and probably wasn't swimming during the first two and protected by Artemis for the third. Jason we know was swimming as he killed a sea monster but the Romans seem less fussed by the Big Three prophecy also Jason was protected by Hera quite a lot. Hazel was dead at the time so unaffected.
Answer: Looking back on it, it does seem odd that Thalia, Jason, and Nico can swim in the sea. One reason may be that Poseidon is a more lenient god and doesn't mind it. But, in traditional mythology, Poseidon was aggravated more easily. But that still doesn't explain why Jason, Thalia, and Nico can swim but Percy cannot fly.
It is true that Poseidon is older than Zeus but the younger brother is the king of the gods and ruler of the universe. Therefore, Zeus can protect his children since he has power over Poseidon but Poseidon cannot easily do the same because Zeus is his superior in rank. It is shown that Zeus does like his two known children (Thalia and counterpart Jason). It is shown when Zeus kept Thalia from dying by turning her into a pine tree. I think why he couldn't just save her by making her human was because it'd be too obvious that he was favoring her and would upset the balance in Olympus and around camp. As for Jason, Zeus even says  it himself:

"My son." Zeus clasped Jason's shoulder. "There is so much I would like to tell you..."
The god took a heavy breath, making the air crackle and Jason's new glasses fog up. "Alas as the king of the gods, I must not show favoritism to my children. When we return to the other Olympians, I will not be able to praise you as much as I would like or, give you as much credit as you deserve."

As for Hades, one answer might be that the Olympians are much too scared of him. They gave him the Underworld and no throne upon Olympus. This may be because of his dark aura and just how deadly he could be. Evidence shows when he captured Persephone, Zeus didn't hurry to help, his idea or not. But, it doesn't specify when/if Nico actually swims so, he is safe. Bianca and Hazel don't need to be too wary because, after the Last Olympian, the Big Three remains more calm about killing each others' children. Hazel, was dead and Bianca was in the Hunters of Artemis, protected by Lady Artemis one of the children Zeus favors, thus protecting Bianca.
As you can see, these are some possible reasons why Poseidon does not kill the other demigods when they cross into his territory.
Answer: Poseidon is generally a nicer guy than his brothers, Hades and Zeus. I mean, think about it.

"As for my brothers," Zeus said, "we are thankful"—he cleared his throat like the words were hard to
  get out—"erm, thankful for the aid of Hades."
  The lord of the dead nodded. He had a smug look on his face, but I figure he'd earned the right. He
  patted his son Nico on the shoulders, and Nico looked happier than I'd ever seen him.
  "And, of course," Zeus continued, though he looked like his pants were smoldering, "we must . . . um
  . . . thank Poseidon."
  "I'm sorry, brother," Poseidon said. "What was that?"
  "We must thank Poseidon," Zeus growled. "Without whom . . . it would've been difficult—"
  "Difficult?" Poseidon asked innocently.
  "Impossible," Zeus said. "Impossible to defeat Typhon."

Zeus seems a little less than eager to recognize his brothers as heroes.

He held out his arms and gave me a hug. I realized, a little embarrassed, that I'd never actually hugged my dad before. He was warm—like a regular human—and he smelled of a salty beach and fresh sea air.

Okay, okay, so Poseidon never hugged Percy before that, but at least he hugged his son, which Zeus did not. I mean, not his daughter. And Hades did not hug Nico. Does this give Poseidon some credit?
Do I even need evidence to convince you that Hades is not generally a very nice guy? Sure, Maria di Angelo, but I did mention generally.
So, yeah Poseidon tends to be nicer. I think it's the thing about water and blue and other stuff that Poseidon is that god of that we also attribute to calmness. I mean, the god of the dead and the god of lightning? That doesn't sound very...calm.
And after that very long list of evidence, we can draw the conclusion that Poseidon is the nice one out of the Big Three. So consequently, Poseidon would be one that is willing to let others into his domain without destroying them the second they enter (not that enemies will get a massage or anything).
Comment: I'd agree with the whole thing, but you're forgetting the god of earthquakes. They literally called Poseidon Earthshaker
Answer: It's because Zeus thought Poseidon took his master bolt. And the problem became worse when Poseidon claimed Percy, to which Zues theorise that poseidon sent percy to steal the bolt (because gods arent allowed to steal each other's weapons). And Hades also wanted to kil Percy because he too thought Percy was responsible for his weapon, the helmet of shadows or something (which was also missing). So basically any child of poseidon was thought to stole the weapons, and percy just happened to be the only one then.
Comment: Welcome to SciFi.SE! You seem to be answering the wrong question - the question is asking why Poseidon didn't ban the children of the other gods from swimming, given that Zeus banned Percy from flying. You're answering the question of why Zeus banned Percy from flying.
Comment: @F1Krazy On the other hand, by giving specific reasons why Zeus banned Percy from flying (i.e. more than just "child of a different one of the Big Three"), this implicitly answers why children of different Big Three gods weren't banned from swimming - because all those special reasons don't apply to them.
Answer: According to book lore, Poseidon is just. A lot more chill about that stuff. Zeus is, for lack of better wording, an ass, and I think Hades was just trying to keep up the Big Bad persona (also who WOULDN'T be defensive like that after losing their Special Magic Murder Item? And he kicked Annabeth and Grover, too, so there's that.)
Also I think there was something, generally speaking, with Nico in the third book?? Not "I'll get murdered" but more "what if I drown and also what if someone gets mad?" Nothing actually happens, but hey, a kid who JUST learned about real Gods had enough wits about him to be cautious, at least!
Comment: Hi, welcome to the site. You could improve this answer by adding some direct evidence from the source material, regarding Zeus and Poseidon's respective temperaments.
Comment: Hi, welcome to SF&F.  What you say might be correct, but it's basically the same thing most of the existing answers say.  Please only post answers when you have something substantial that isn't already covered.


Visa requirements to enter the UAE for a Portuguese citizen

Question: I am a Portuguese citizen and I heard that there is no visa required for entering Dubai (United Arab Emirates.) I plan to book a return ticket and will exchange funds for my business trip to the UAE. Is there anything else I need to do? Do I need to fill any online form or similar? Or is it just simply booking the flight tickets and flying to Dubai?
Comment: Thanks for the prompt reply, there is also the possibility of my spouse whose an Indian citizen accompanying me. We will be traveling from India if it helps. Our duration of stay in the UAE is for around 2 weeks.
Answer: The United Arab Emirates has a very easy visa policy for citizens of the EU: just show up, nothing else needed.  You don't even need to fill out an immigration card.
You do need a passport valid for at least 6 months, and in theory funds sufficient for your stay and a return ticket, although I've never been asked for either.
Answer: Book your ticket and enjoy your flight. Upon arrival you will be stamped into the country by the immigration officer.
Keep in mind the following restrictions:

Passports and other documents accepted for entry must be valid for a minimum of 6 months from the arrival date.
Passports and other documents accepted for entry issued to passengers who stay less than 3 months must be valid for a minimum of 3 months from the arrival date.
Passengers with a handwritten passport are not allowed to enter.
Passengers with dual nationality must present the same passport at immigration upon entry and departure.
Visitors with an extended validity in their passports are not allowed to enter.


Will switching tunings affect my guitar's action or truss rod?

Question: I have an ovation acoustic guitar. It's only about a year or two old. However it's always had terrible action (though this might be an issue with its been width). It was so bad that I was tuning to D standard and had fairly light strings (.12 gauge). I got it set up at a guitar center recently. They told me they could only lower the action a little bit. I believe they said the truss rod could only be lowered half a step? They told me that switching between an open D and D standard was messing up the tross rod and if I continued to switch between tunings, fixing the action would require much more money. Is this true? I also tend to do this on my electrics but the action isn't so bad on them.
Comment: I think you need to find a better place to take your guitar to for setups. Either that or there was some major miscommunication between them and you. There is a limit to how low the action can be on a guitar, but using lower tunings would only possibly cause backbow, which can usually be corrected. Instead of blaming you they should be asking how you want to tune it and then giving you the best possible setup for that tuning, as well as recommending future care.
Comment: If this is a nagging concern for you, then you may wish to consider using a "partial capo" to achieve different tunings.  There is one called a "spider" that allows you to capo-fret individual strings.  Of course this would mean that your are translating absolute pitch while maintaining relative pitch.  For example, to achieve the equivalent of a drop D tuning, you would capo the first five strings at the second fret.  As noted, this would in effect translate the absolute pitch up by a full tone.
Comment: So switching between tunings won't have any permanent effect on the guitar? And why do people suggest one guitar per tuning?
Comment: Some effects are long-term but not permanent, but if the guitar itself is only a few years old it can almost certainly be corrected even if something has gone wrong with it. Humidity is more likely to cause permanent guitar problems than tuning, although if you have a round-backed Ovation then you have little to worry about humidity. Usually lower-priced acoustic guitars have higher actions because building a guitar with precise alignment of the neck, etc., is expensive. I'm really surprised they didn't just try to sell you a better guitar.
Comment: If you set up the best possible action for one tuning, then it's not going to be the best action for any other tuning, so changing tunings without adjusting the action at the same time just messes up the action (not the guitar itself). If you really want to play in more than one tuning with an excellent setup all the time, then having a guitar for each tuning is a good way to make it so it doesn't take you a couple hours to change tunings and then fine-tune the action.
Comment: @munchschair, one tuning per guitar is _convenient_, instead of retuning, especially if you want to switch between them a lot.
Answer: Lots of misperception here!
Besides changes in humidity, using different gauge strings is the next-largest single contributor to action changes/problems, as is tuning the entire guitar up or down a whole step or more.
Using alternate open tunings will typically have very tiny, mostly-irrelevant affects on the playing action.
The purpose of the truss rod is to counteract the many pounds of pull of the strings on the neck.  Tightening it bends the neck back (lower action) and loosening it bends the neck forward (higher action).  The height of the bridge also matters a lot, and my guess is that this is your actual culprit.
Also...the only real reason for using multiple guitars for multiple tunings is to minimize the amount of time your audience spends listening to "the tuning song" during your set.  It really busts up the flow of a performance.  A modern, well-constructed guitar doesn't have any issue with changing tunings on-the-fly.
Also...if the tech saw that he had no more room to tighten the truss rod, and you're using light gauge strings, and the action is objectionably high, it's entirely possible that you have a broken truss rod.
Answer: If the neck is already straight, the action can be lowered by lowering the saddle: loosen the strings, remove the saddle from the bridge, and file the bottom of the saddle.
Filing should be done carefully and in a straight line, by laying sandpaper on a flat table and rubbing the bottom of the saddle on it, so that the bottom of the saddle remains straight.
Also, do it a little bit at a time and repeatedly test it until you get it the way you want it.
An even better option is to buy a few spare saddles, so you can test without having to worry about going too far. If you go too far with a test saddle, place something under it, until you figure out the perfect height, and then file your main saddle so that it achieves exactly that action.
Answer: A little confusion here! .012" set of strings isn't 'fairly light' - it's about standard. The truss rod doesn't get adjusted in 'steps'. If they meant half a turn it's still meaningless. The truss rod adjustment is only part of sorting out the action. The bridge height is just as relevant. As is the effect of heavy strings. They won't change the action, once they're on, but they will make it harder to play. Suggest taking it to another guitar tech., who may look at it differently. Changing tunings WILL affect the action, rather than the truss rod, so maybe, on that particular guitar anyway, doesn't come highly recommended.
Answer: Switching tunings can definitely affect your action - particularly if you are changing the string tension more than a semitone or half step on any given string.  I know this is true because I have had numerous guitars set up for lowest action without buzzing.  I like to tune my guitars a half step flat (D#).  I tell my luthier that - but if he forgets and sets up my guitar for standard tuning, I get buzzing and I have to go back and have it adjusted again for the drop tuning I use.
Having said this, you can have your guitar set up with higher action, and it will play buzz free in many alternate tunings with no further adjustment between tunings.  I know several guitarist who regularly use four or more different alternate tunings on the same guitar in a live show.  They only change the tuning between songs - not the set up.
As far as what it can do to your truss rod - if every time you change tunings, you adjust your truss rod for that specific tuning, you could in fact wear out the adjustment mechanism by adjusting it back and forth too often.  It's mechanical and can wear out if adjusted too often.  But it is unlikely that you would be adjusting the truss rod between tunings.
If you do find that for your playing comfort and to keep the action as low as possible and not have any fret buzz, that you are feeling a need to adjust the truss rod between alternate tunings, I would definitely recommend a second guitar for the alternate tuning.
Again, many professional performing guitarist get away with one guitar and use that guitar for many alternate tunings during a show.  Other professional guitarist prefer not to take the time to change the tuning - so they have two or more guitars on stage for their show - each tuned differently.  In the extreme, there are a few artist that almost use a different guitar for every song in their show - but they are at a popularity level where they get their guitars for free and they have a person whose job is to bring them the right guitar for each song and they use a wireless instrument receiver.
If there is nothing wrong with your guitar, you should be able to find a compromise set up that will work for any of the tunings you use.  If you want the lowest possible action for each tuning, I recommend using multiple guitars.  I don't think it makes sense to adjust your truss rod every time you change tuning.
Good luck.
Answer: Switching tunings will not effect it as much as people think, but that's not to say it cannot or will not.
You do hear that if you tune your guitar to, oh let's say Open E, that it can hurt the guitar if left in that tuning. This may be true depending on the type of guitar, and if the guitar is left in Open E.
The more imminent issue will be string life. Constantly changing tunings will shorten the life of the strings. It's like anything metal. If you bend a paperclip back and forth it will eventually break. Changing tunings, stretches and relaxes the strings. Granted the effect isn't as quick as bending a paperclip back and forth until it breaks but each stretch weakens the tensile strength of the string.
That being said, I assume this is why some artists will pick one instrument, and leave it in the alternate tuning they use the most. An electric guitar can handle constant tuning changes better than an acoustic guitar. The strings will still have the same issue as acoustic guitars.
If you use lighter strings on the acoustic guitar, that will help reduce any possible guitar issues. Another thing you can do, instead of tuning to Open E, a lot of guitarists will tune to Open D, and then use a capo at the 2nd fret. This method puts less tension on the strings, and you get 2 different tunings you can use. I have one of my electric guitars tuned to Open E. I use lighter strings anyway so that combined with it being an electric guitar, seems to have eliminated any possible guitar issues. I haven't had an issue with it yet.
As far as action goes, the action can be affected by changing tuning: for example if you go to a tuning where, you are tightening, 3 of the 6 strings to get the desired notes for the new tuning, you are placing more tension on the neck, and it can increase the bow. This can be countered with a truss rod adjustment in most cases.
Which is another reason some guitarist will chose one guitar, and leave it in the desired tuning. If your a gigging musician, you don't have time to make truss rod adjustments between songs.
Answer: To answer the question in the title: Yes, somewhat. The truss rod wants to pull back. The strings want to pull forward. But the changes should be slight.
But the answer in the question text: Different styles of playing require different actions, and with loud strumming of cowboy chords, you want a higher action so the strings don't rattle against the frets. It can go too far, and it sounds like your guitar has gone that way.
If you can capo at the first fret and fret the last, there should be some room at say the tenth fret between the fret and the string. This is called relief and it should be small. IIRC  about a dime's worth, but look online for guitar setup guides for more info, and turn the truss rod a quarter-turn at a time.
If that's about right, your guitar neck is fairly straight and the problem is your bridge. You could try to sand down the bottom of the saddle to bring it closer, or find a better repair shop than the one you used.
You say it's a two-year-old Ovation, and while even great guitars can need some adjustment to get it right for you, I'm frankly surprised that a new guitar from a reputable brand is so unmanageable. Good luck.


Why do only ketones exhibit keto-enol tautomerism?

Question: Why can't esters or acids or their derivatives exhibit tautomerism? I mean if they did, then there would be a conjugation between lone pair electrons of oxygen and pi electrons adding to their stability. Then why don't they exhibit similar tautomerism?
Comment: Though I do not have a reference, I believe that some esters would exhibit similar or the same behaviour as ketones. At least $\alpha{}$-protons of esters are far more acidic than their esterless counterparts, which proves a similar effect is applicable on esters.
Answer: Esters, amides and acids do exhibit tautomerization to the enol form, but the enol content in these compounds is just much less than that found with aldehydes and ketones. Why?
The keto-enol process is an equilibrium; to understand where an equilibrium lies, we must compare the relative stabilities of the products (enol) and reactants (carbonyl compound).
Let's compare some resonance structures for an ester and a ketone and their corresponding enols.

The ester is stabilized by resonance structures such as A, whereas in the case of the ketone, the analogous resonsnce structure A' contributes, but not nearly as much; so ester carbonyls are stabilized compared to ketone carbonyls.
In the enols, the ester resonance structure B is not particularly favorable due to the negative charge on carbon and positive charge on oxygen, just the reverse of what we would want based on electronegativities.  At least in the ketone case resonance structure B' has a positive charge on hydrogen, so resonance structure B' contributes more than B (this is why carbon-carbon double bond stability increases with increasing alkylation).  As a result the enol resulting from the ketone is stabilized compared to the enol resulting from the ester.
Just where the carbonyl-enol equilibrium lies will depend on the relative stabilities of the carbonyl compound and the enol.  As we've just discussed, the ester carbonyl is stabilized relative to the ketone carbonyl, this will push the equilibrium further to the carbonyl side for the ester.  Also, the enol from the ketone is somewhat more stabilized than the enol from the ester, this will push the equilibrium to the enol side for the ketone.
So both factors, starting material (the carbonyl compound) stability and product (enol) stability will work to increase the enol content for ketones and reduce the enol content for esters.
Comment: In esters why can't the positive charge be on adjacent carbon instead of oxygen? That way the newly formed pi bond and the lone pair electrons on oxygen would be in conjugation adding to the stability of ester. Why isn't that possible?
Comment: To draw a resonance structure for the ester with the positive charge on the carbon adjacent to the carbonyl carbon you would need to have hydride ion ($\ce{H^{-}}$) as part of the resonance structure.  Hydride ions are very high energy, consequently resonance structures involving them are very high energy and do not contribute significantly to the overall description of the molecule.  BTW, if the above answer was helpful, please mark it as accepted. Thanks.
Comment: Pardon me but I didn't understand why an hydride ion comes into the picture. Just like in keto-enol tautomerism a H+ ion will come out and then later form a bond with oxygen, right?
Comment: You commented, "Just like in keto-enol tautomerism a H+ ion will come out and then later form a bond with oxygen, right?".  Yes, that is right.  But in your first comment you asked, "In esters why can't the positive charge be on adjacent carbon instead of oxygen?"  Try writing a mechanism to create such a structure, I think you will find that a hydride ion is required somewhere in the process.
Comment: Yeah you are right about the +ve charge on the adjacent carbon issue. But can there be a double bond between ester carbon and the adjacent carbon due to tautomerism between those 2 carbons and oxygen?
Comment: Yes, that is the enol form of the ester.
Comment: Good answer, I would have written something similar myself if you had not done it first.


Retrieve parent and child objects with minimum DB hits using Dapper

Question: Object hierarchy may be like Customers and Orders, and I want all customers with orders as List property. Typically, in ado.net, we loop through each customer and load their orders which might result it N number of DB hits with N customers. So, is there are any way to achieve this directly in Dapper, if not, is there better way to achieve this.
Edit
I've idea of retrieving all records at once using join but customers get duplicated. And again, I need to construct the required object from resultant DTO. But I don't know if it is best possible way or there may be any other approach which I might be missing esp. w.r.t Dapper.
Answer: You can write a query joining customer and order tables. That will reduce the no of calls to DB but it will increase the amount of duplicate data you fetch from db. But that depends on the number of columns that you fetch from customer table.


Is it legal to use a chess database in correspondence chess?

Question: Someone told me that you can use a chess database for correspondence chess, but this seems a little like cheating. Does anyone has some information on this subject.
Comment: What kind of correspondence chess do you play?
Answer: According to the official rules of the International Correspondence Chess Federation, you are allowed and encouraged to. It is regarded as learning an opening. Of course, there are different rules for some sites, but most sites follow the ICCF rules.
Comment: At ICCF even engine use is fine.
Answer: In accordance with the reference to the ICCF, I think that it's also placed upon you and your correspondent to agree to such things: It's not something that should be kept secret from your opponent.
Comment: I don't agree at all. If something is allowed by the rules, the assumption is that everybody will make use of it. If you want to restrict yourself voluntarily and the game isn't competitive, you may ask your opponent if he wants to as well, but there's no reason for him to agree.
Comment: Fair enough. In my correspondences, we usually have a very simple preamble where we set color, time limits on responses, and the like. In the past, my usual consensus is that you can consult theory (openings, etc) but not feed the board to a chess engine. I could do that on my own, so why would I need/want someone else to do that? Perhaps I misunderstand the use of a "chess database" as an engine.
Comment: I'm not forcing anything with my statement, just saying that some open communication can be a welcome avenue for agreeing about terms. Think of them as "house rules" among gentlemen/women. It's more for further clarification of details and not a base set of rules. And this person asking obviously has some fine tuned questions of said established rules, so a quick banter back-and-forth can easily and quickly set one's mind at ease.
Comment: I took "placed upon you" to mean it was something people should normally do. Nobody starts a normal competitive chess game with a debate about the choice of house rules, and that doesn't happen in correspondence either, in my experience.
Answer: My teacher always said that using engines and suchlike didn't matter, as generally players in correspondence chess can analyse deeper than a computer can. That was a few years ago, so the state of technology might have changed now. Also, this probably only applies if you are above certain level of ability.
Comment: Everybody in serious correspondence chess relies heavily on computers, but on the other hand, people who *only* rely on computers don't get very far.
Comment: So if I relied solely on Stockfish with really good hardware while playing correspondence chess, I would not do well?
Comment: @wired_in It depends on how good you and your opponent are, how long you have between moves, and how much time you spend on computer analysis. If you have a grade of 1000, and spend 30 hours on computer analysis per move I'd imagine you would do quite well.


Hypernym of "movie" and "play"

Question: I'm looking for a hypernym to replace "movies and plays" in "Some movies and plays ...". I think that there's a word that describes both but I just can't remember it.
Comment: Perhaps "some shows" . "Shows" was traditionally used for both and, while it might be a little like calling a "soft drink" a "soda" I don't think it's shockingly dated.  "broadway show" (still common), "motion picture show" (not so common)
Comment: Drama, Thespians, players.
Comment: Theatrical performance.
Comment: Some ***entertainment*** perhaps?  Unfortunately, there is much that makes movies and plays very different; it might be too much for them to share a word.
Comment: Might you be thinking of the word **productions**?
Comment: Are you including documentaries in the category "movies"? If not, several of the suggestions here work.
Answer: A Show or a Performance I believe would fit.
Comment: We're looking for long answers that provide some [explanation and context](//english.stackexchange.com/help/how-to-answer). Please explain why your answer is right, ideally with [citations](//english.stackexchange.com/help/referencing). Answers that don't include explanations may be [removed](//english.stackexchange.com/help/deleted-answers).
Comment: Unfortunately, I am my own resource having had a conversation with a professor on the exact topic. EMBARRASSING. I realize I should have looked up and cited something a bit more concrete. But, I tried..  Should I delete? I respect your site very much. I apologise.
Comment: at least mention that in the answer
Answer: I suggest aiming a bit more narrowly than Jezebelisgone's suggestion of show or performance and using the two-word term scripted performance, where scripted refers to the following sense of script (as defined in Merriam-Webster's Eleventh Collegiate Dictionary [2003]):

the written text of a stage play, screenplay, or broadcast; specif : one used in production or performance

As the terms stage play and screenplay suggest, films and plays have in common that the performers generally work from a carefully developed script of speeches that the actors memorize and recite in character. Many types of shows and performances (dance recitals, juggling acts, etc.) do not do this. Nevertheless, scripted performance does not apply exclusively to films and stage plays. TV shows, radio broadcasts, comedy routines, and even political speeches (for example) could be categorized as scripted performances as well.
Answer: As suggested in a comment: entertainment, according to Cambridge Dictionary:

shows, films, television, or other performances or activities that entertain people, or a performance of this type

Attribution: (Definition of "entertainment" from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

Hypernym of "movie" and "play"


Canceled claims considered prior art?

Question: If the application for US 7,156,537 B2 was rejected on two occasions during examination and two claims were canceled from the patent, then why is the figure associated with the canceled claims still in the published patent and are they considered prior art?
Answer: The figure associated with the canceled claims is in the published patent because the patent was never amended to remove it. There is no requirement to remove material not claimed from a patent application.
Yes, everything disclosed in the published patent is available as prior art.
Answer: Everything in the published patent along with everything in the publicly available file history associated with the application is considered prior art.
Documents are eligible for use as prior art as of the date they are publicly available. In this case, all versions of the application, even canceled claims (and even if some parts of the specification and/or drawings were canceled) could still be prior art because they remain part of the public record.
Regarding the claims and related description, everything in the claims must be within the scope of the application specification and/or drawings. However, everything in the specification and/or drawings does not need to be within the scope of the claims. In other words, there can be (and typically there is) lots of subject matter described in the specification and/or drawings that is not covered by the claims.

Canceled claims considered prior art?


Turing machine and coming up with an idea

Question: I read many things about the Turing machine and understand how it works but what I can't get the grasp of (and what none of the books seem to try to teach) is how should I approach a problem I am given to solve? I mean: checking if a word is a palindrome, for example, consists of 11 states in the book I'm learning from. For my current state of knowledge, just sitting over an empty sheet of paper and coming up with all these states seems next to impossible, to say the least. When I try to do something like this, I get stuck immediately since I don't know what should I do to make these states work somehow "together". I don't have such problems when programming in some prog languages but here, I just can't figure out how I should approach something consisting of some n-teen states. Could you please point me some direction to learn about it?
Comment: I don't think states are where you should be starting. Write down an example input. Think of how to move the head and what values to write. Then figure out what states you need to enforce such movements.
Comment: Karolis' comment above is essentially what programming is about in general. Decompose a problem into smaller pieces which you think are easy to implement, and then compose those pieces together in an appropriate way. Writing a Turing Machine to solve a problem gives some insight into how small those elementary pieces can be made.
Comment: This is just to show that humans are not universal Turing machines ;-)
Answer: Just to expand the comments above, you should try to find a high level algorithm, and then refine its steps in smaller pieces.
For example, if you want to recognize palindrome words, a high level agorithm can be:
1. check if the leftmost symbol is equal to the rightmost symbol
2. if they are not equal reject, otherwise delete them
3. if there are other symbols then goto 1, otherwise accept

That can be refined in the following way:
1.1 move the head on the leftmost symbol
1.2 "store" its value
1.3 if it is the only symbol left then accept (w has an odd length)
1.4 otherwise move the head to the rightmost symbol
2.1 compare it to the "stored" one
2.2 if they are not equal halt and reject, otherwise
2.3 delete the rightmost symbol
2.4 move the head to the leftmost symbol
3.1 delete it
3.2 if the tape is empty halt and accept, otherwise
3.3 goto 1.1

The steps are "implemented" using the internal states of the Turing machine.
While designing the Turing machine you can name the states with labels instead of "q0, q1, q2" to make the design process easier.
If you have a single tape Turing machine, the step [1.2 "store" its value] means that you must use the internal states to "remember" the symbol read while the head moves to the rightmost one.
Suppose you have two input symbols $a,b$ and $-$ is the blank symbol, then you can use a set of states La,L'a,CMPa and Lb,L'b,CMPb to represent (store) the leftmost symbol read; so steps 1.1, 1.2, 1.3, 1.4, 2.1, can be implemented in this way:
     |  a      |   b     |   -
START| a,R,La  | b,R,Lb  | -,R,START << move right until you find a symbol
La   | a,R,L'a | b,R,L'a | ACCEPT    << step 1.3
Lb   | a,R,L'b | b,R,L'b | ACCEPT    << step 1.3
L'a  | a,R,L'a | b,R,L'a | -,L,CMPa  << step 1.4
L'b  | a,R,L'b | b,R,L'b | -,L,CMPb  << step 1.4
CMPa | -,L,MVL | REJECT  |           << compare to a
CMPb | REJECT  | -,L,MVL |           << compare to b
MVL  | .......                       << move left

As you can see after reading the leftmost symbol the states are doubled:
Lx we are on the first symbol after the leftmost one (which is symbol x)
L'x we are moving rightward from the leftmost symbol x
CMPx we are comparing the rightmost symbol with the leftmost symbol x

Comment: Yes, the head is usually on the leftmost input symbol (unless problem description states otherwise); so in my step list the step 1.1 is a little bit redundant and you can ignore it. Furthermore if you try to complete the Turing machine description that I sketched in the answer you'll realize that the START state can be modified to "ACCEPT" on the blank symbol, and in this way it implements the two steps 1.2 and 3.2 at the same time (the "goto 1.1" is implicit).
Comment: Great explanation, thank you :) Also, I have a question - can I always presume the head is on the leftmost element unless problem description states otherwise? I see some problems in my textbook have information about the initial position of the head - does that mean that when it's _not_ stated, I can always think of it as being on the leftmost end or I can presume nothing and always have to write something that works regardless of the initial position?
Answer: Try using visual designers like this or turingkara-en, which also contains exercises.
Keep in mind that the TM is meant to be a theoretical, minimalistic model to simplify proofs. Programming on the other hand will get nasty fast. So don't think it's a shame to have problems with programs requiring more than half a dozen states.
Answer: Suppose you're given some string over a three-character alphabet $\{0,1,\,\_ \}$, where the latter is the blank character. You'd like to know if the input consists of a single "word" over $\{0,1\}$, ending with one or more blank characters, which is a palindrome. (There could be multiple words later on the tape, but you're not paid to care.) How could you figure this out?
A word $W = a W' b$ is a palindrome if and only if $a = b$, and $W'$ is also a palindrome. To find the end of the word, you'll need to look for the last character preceding a blank; and whether or not $W$ (or $W'$) is a palindrome, you don't really need to hang onto that first input character $a$ for very long.  So you can probably proceed by blanking out the first character (while "storing" what value it is in one of two branches in the program code, using some of the states as a limited memory), and basically shuttle back and forth between the left- and right-hand sides of the string, checking whether the two ends of the word are the same. This is basically the same as working it out for a two-hundred long string of characters over the alphabet where you might scratch out letters on either end (rather than blanking, but it's basically the same) until you found a mismatch, or made your way to the middle.
Generally when designing a Turing machine to solve some problem, you have to find some way to break up the problem into little pieces that can be easily solved by either making local changes to the input, or by recording some piece of information in some long branches or decision-tree-like structures in the state transitions while the machine head searches back and forth for the information that it needs to solve the problem. The challenge in solving problems on a Turing machine is to find a way that involves little to no local memory at the machine head, because it has no stored memory of its own aside from what state it is in; and so it's a sort of a challenging parsing problem. But in the end it's doing basically the same thing — in an extremely primitive way — that you do when you solve a problem involving a long input: it simply reads and rereads the input as it needs to, going back and forth. For simple problems such as this, if you think very carefully about how you personally would go about solving such a problem (perhaps while sleep deprived and therefore not having the sharpest memory), you can start to figure out how to write the state transitions for the problem.
Now, if you're told to do it in a specific number of states, that can be difficult, but certainly you can start by trying to find a straightforward way of doing it first, and then thinking (if you've used too many states) if there are any simplifications or optimizations that you can apply, by taking advantage of the structure of the problem somehow. There isn't any sort of general procedure that you can apply to do this, so it's basically down to whether or not you can find the essential structure of the problem (and whether or not your exercise is free from typos).


Madhab of the salaf and the 4 madahib (Maliki, Shafi'i, Hanbali, Hanafi)

Question: Salamo3alaykom, I don't understand when scholars refer to something as "madhabu as-Salaf u Saalih". Aren't the Madahib 4 which are already known? I don't want to discredit the biggest scholars of this Ummah, but why don't they say "manhaj salafu saalih" instead of madhab salaf as saalih? I don't understand because the madahib came after the three early generations and therefore those 3 generations didn't follow a madhab (please correct me if I made a chronological mistake, I'm definitely not good at Islamic sciences unfortunately). Can someone clarify and especially not put this question on check as unclear? Jazakom Allah
Answer: What does madhhab as-Salaf mean?
First saying madhhab(u) as-Salaf as -Saalih is suggesting that the early generations of Muslims had a (single) madhhab which is wrong.
Secondly madhhab in the context of as-Salaf as-Salih or in general is a term that can be used in at least two different Islamic topics:

'Aqidah (belief) and
fiqh (jurisprudence)

and in both there are different madhhabs in Islam.
Basically most people when referring to the madhhab as-Salaf as-Salih mean 'Aqidah as at least in this the Salaf rather had an agreement on what and how to interpret even if we will find differences of opinion in the details (for example will we see our Lord or not). And this is a topic where the scholars of the four madhhabs clearly followed the mainstream.
When it comes to fiqh they had different madhhabs and the fact and reasons why the four madhhabs remained is explained in a lot of posts on the site.
Who are meant by "as-Salaf as-Salih"?
Note that Salaf in Arabic refers to all kinds of predecessors! So my father/mother/grandfather etc. is "my Salaf". Therefore by adding the adjective as-Salih the meaning is more restricted.
The definition of as-Salaf as-Salih which is the well-known is that it includes the three first centuries not generations so it certainly covers the four madhhabs and even al-Bukhari, Muslim and many more. Nevertheless there's a difference of opinion based on the interpretation of the word "Qarn" "قَرْن" in the sahih hadith which literally means century while others interpreted it as generation (note that the referenced links show differences in the hadith):

The Prophet (ﷺ) said, "The people of my generation are the best, then those who follow them, and then whose who follow the latter. After that there will come some people whose witness will go ahead of their oaths, and their oaths will go ahead of their witness."
  Ibrahim (a sub-narrator) said, "We used to be beaten for taking oaths by saying, 'I bear witness by the Name of Allah or by the Covenant of Allah."
  (On the authority of 'Abdullah ibn Masu'ud in Sahih al-Bukhari 1, 2 and 3 and in Sahih Muslim 1, 2 and 3 expressing a doubt whether he referred to three or four generations and in Sunan ibn Majah)

Imam an-Nawawi favored the interpretation of generations and said it refers to the Sahabah (companions), the Tabi'yn (followers) and the Tabi' at-Tabi'yn (the followers of the followers).
But anybody following their path counts or can be referred to as among them by the wider definition and therefore one could safely say that this term can be used for the good people of the three first centuries which makes both coexisting definitions alike. As Allah the almighty says:

And the first forerunners [in the faith] among the Muhajireen and the Ansar and those who followed them with good conduct - Allah is pleased with them and they are pleased with Him, and He has prepared for them gardens beneath which rivers flow, wherein they will abide forever. That is the great attainment. (9:100)

Note that some sources consider imam abu Hanifa as a Tabi'y.
What is the difference between "madhhab" and "manhaj"?
As for whether madhhab or manhaj these terms can be regarded as synonyms madhhab means path, way or could be explained as the choice or opinion while manhaj means the way and is more related on the methodology. Both terms are valid and can be used to express the view of scholars of the early 3 first centuries.


Why are Fauxwood vertical blinds not as thick as Fauxwood horizontal blinds?

Question: Why are Fauxwood Vertical blinds not as thick as Fauxwood Horizontal blinds? I received a lot of samples. Is it because vertical blinds structure rail cannot hold something as heavy? I buy blinds, not only for lighting but as slight protection against window insulation during the winter months.
Comment: Ask the company. They would know what, if any, reason there was for the difference. Unlikely that anyone here does.
Comment: hi @Ecnerwal this is for many different types of brands, I asked customer service, they didn't really know either
Answer: It is just a guess, but something held vertically from the top and still be straight, doe not need to be thick at all. Now take the same piece of material used horizontally and it will potentially sag between supports. Thicker material will withstand sagging over a given distance, especially over time where gravity will deflect an item that may have been straight initially.
Answer: At the first glance, there seems no logical reason for them to use two different thicknesses for horizontal and vertical blinds. For vertical blinds, thicker material will cause more sag and increased difficulty in open-close the blinds due to more friction, but these are not problems usually associated with the horizontal blinds, then, why use thicker material for horizontal blinds? My guess is that because of exactly the same reason - to prevent sagging, but of different parts. While the horizontal blinds need more rigidity to span the opening without the blind leaf from sagging, the vertical blinds need to reduce the hanging weight of the vertical leaf that causes sag to occur.


What does 1 Corinthians 1:27 mean?

Question: What does is it mean that God used the foolish in the world to shame the wise?
Comment: You would need to give us some context. What is it that you do not understand about the statement of fact : that God used the foolish in the world to confound the world ? Paul's discussion of the subject, in the quoted chapter, is fairly clear, I would have thought.
Answer: 1 Cor 1:27 cannot be understood in isolation.  This part of Paul's argument begins in V18.  In this passage is at pains to pint out two things:

V18 - the Gospel appears foolish to the Jews and the Greeks, for largely the same reasons - the Messiah was born illegitimately, and died as a criminal - Some hero!!  A stupid idea to non-Christians that made no sense whatever.  Paul then quotes Isa 29:14 in support of this obvious conclusion and then pivots to the next point;
V20 - the greatest intellectual human efforts are miniscule compared to the wisdom of God.  (Recall Isa 55:9, As the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts.)  Paul expresses it this way, (v25) "For the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength."

Conclusion: V21 - God uses what looks stupid (= "foolish") in the world's eyes to do great things for those who believe, namely save hopeless sinners.
Paul then elevates ordinary people to something greater than nobility by saying (V26), "Not many of you were wise by human standards; not many were influential; not many were of noble birth."
Next Paul makes a series of parallel statements that all say the same thing:

God chose the foolish things of this world to shame the wise (V27a)
God chose the weak things of the world to shame the strong (V27b)
God chose the lowly things of this world and the despised things--and the things that are not--to nullify the things that are (v28)

That is, what the world things is stupid (= foolish, ie, an illegitimate crucified criminal Messiah) is the very thing that saves us.  Jesus appeared weak because He allowed Himself to be killed; But the forget the best part of the story that Jesus rose from the dead and now reigns with God in heaven!
Thus, it is true - "But God chose the foolish things of the world to shame the wise" (V27).
Benson observes:

In this passage the apostle imitates the contemptuous language in
  which the Greek philosophers, and men of learning, affected to speak
  of the Christian preachers: yet, as he does it in irony, he
  aggrandizes them. The first preachers of the gospel, as Bishop Newton
  observes, "were chiefly a few poor fishermen, of low parentage, of no
  learning or eloquence, of no reputation or authority, despised as Jews
  by the rest of mankind, and by the Jews as the meanest and worst of
  themselves. What improper instruments were these to contend with the
  prejudices of the world, the superstition of the people, the interests
  of the priests, the vanity of the philosophers, the pride of the
  rulers, the malice of the Jews, the learning of the Greeks, and the
  power of Rome!" But the weaker the instruments who converted the
  world, the greater was the display of the power of God by which they
  acted.
Answer: Many Greek intellectuals considered that the Christian message was a foolish superstition. Rather than argue with them, Paul accepted, for the sake of argument, that they were right. Thus, God had chosen a "foolish" message to shame the "wisdom" of the World.

What does 1 Corinthians 1:27 mean?


Can Emrakul's Evangel save me from "destroy all creatures"?

Question: My opponent played a "destroy all creatures" card. But I have Emrakul's Evangel on the field. Is there any way that if I use his ability so that some creature will survive?
Answer: Unfortunately, no. If you use that ability in response to their spell, you still lose everything. Here's how it works, assuming nothing else happens:

They cast Wrath of God (or some other card that destroys all creatures). It goes on the stack.
You respond by activating Emrakul's Evangel's ability, sacrificing some number of creatures. It goes on the stack on top of the spell.
The top thing on the stack resolves. That's Emrakul's Evangel's ability, so now you get your 3/2 Eldrazi Horror tokens.
The next thing on the stack resolves. That's the Wrath of God. It destroys all creatures, including the 3/2 tokens you just created.

If you want something to protect you from that kind of situation by giving you replacement creatures, it generally needs to be a triggered ability. For example, Abzan Ascendancy gives you Spirit tokens when your nontoken creatures die.
Answer: No you can't use Evangel to end up with any creatures:

Do not use Evangel - Evangel and all other creatures die when the destroy effect resolves.
Use Evangel - All creatures you sacrifice die and leave 3/2 horrors behind, then all of these tokens die along with all other creatures when the destroy effect resolves.

What you are looking for is to be able to activate the Evangel and have the effect resolve after the desroy effect. The only way that would happen is if the Evangel was activated and in response the destroy effect was put onto the stack, something like Rout could cause that.


How do purely mechanical (early) automatic transmissions know when to shift?

Question: How do early transmissions know when to shift? How do they go to the right gears for the right conditions (heavy acceleration, going up a hill etc.)? I cannot imagine how it is done without electrical components, but it seems like they were purely using hydraulics.
Comment: Yes, with hydraulics. Here is a [description](https://www.defensivedriving.com/blog/understanding-your-transmission-part-2-automatic-transmissions/) of how it used to be done.
Comment: As an interesting source check out Lanchester...
Comment: @WeatherVane Thank you! The link is really helpful!
Comment: The governor controls shift points.
Comment: I think I'm confused. Have you meant "purely mechanical" as in "without electronics" or "purely mechanical" as in "only gears shifting, no torque converter". Because torque converter doesn't shift at all, it's continuous.
Comment: @Agent_L As I said in the description, I meant without electronics.
Answer: //edit: This answer is based on assumption that "purely mechanical" excludes torque converters and we're talking about actual gears shifting, as in "manual gearbox with a mind of it's own".
RPM alone.
When RPM goes beyond certain range, it's a cue to shift up. When RPM drops below another threshold, to downshift. That's all.
The whole point of a gearbox is to maintain engine RPM in optimal range. All other things are just tweaking this match in anticipation of a future change Eg. going uphill you're mentioning is merely a prediction that the speed of the vehicle won't actually increase enough to make the most out of upshift. By applying this prediction you defer shifting - but disregarding the condition and shifting as usual will not make the gearbox unusable, it'll just have to shift down again soon.
Also keep in mind that the bigger the engine, the more the power margin the system as a whole has. So while a tiny, overworked engine needs a lot of skillful shifting to stay in this one tiny rpm spot where it can manage, a big, overpowered engine will easily cover for any shifting mistakes. (That's the original reason why automatics are ubiquitous in USA but unpopular in Europe: US engines are bigger, so the gearbox has so much less work to do.)
Also, as some early mechanical automatics still depended on driver pressing the clutch, all the sophisticated decision making on "when to shift" was still done by a protein-based electrical computer. The gearbox only had to decide if and which way to shift, which is a very simple decision to make based on - wait for it - RPM alone.
Comment: There is no such thing as "economical gear". There is only "economical RPM", and the proper gear is one that matches vehicle speed with this RPM. The "need to accelerate fast" is done by notching into higher RPM, with more power but even more fuel usage. But it's still "keep shifting until desired RPM reached", just the target RPM is different.
Comment: I wouldn't say point of a gearbox is to maintan engine RPM in an optimal range. In my opinion, the point of a gearbox is to have 99% of the time the most economical gear, while providing high RPM for 1% of the time when needing to accelerate fast. It's not thus only RPM, it's also the throttle position that matters.
Answer: Hydraulics or vacuum. Engine spins torque converter and pump, fluid flow directed by valve body for shifting.
Comment: The first automatic transmission was GM's Hydramatic and I don't think that hydraulics are strictly categorized as 'mechanical' but they are 'non-electric'.


Doesn't reduction unnecessarily waste resources?

Question: A moderator closed Doesn't reduction unnecessarily waste resources?. How can I make it not opinion-based pls?
Comment: Hi, it is important for us to have visibility of what has been asked and answered. Please don't delete questions once you don't need them any longer.
Answer: Seems like you're fine at this point.
While it may seem like a small detail, asking words like "unnecessary" and "waste" tend to invite a lot of opinionated debate about what exactly constitutes waste, what's necessary, and so on. The edits that removed that sort of thing, and focused on the factual portions, make it far more likely that you'll get solid, less-opinionated answers.


Fallout New Vegas Hidden Weapon Extra Ammo

Question: Somewhere along the road to Jacobstown in FONV, if you turn right and keep walking, you will find a crashed UFO. There are aliens and if you kill the alien captain and loot him you will find an extremely powerful energy weapon. There is a special type of ammo used only for this plasma weapon. If you know what I'm talking about, is there any more of this special ammo anywhere else in the game?
Answer:
The gun you have found is the Alien Blaster.
The alien blaster has been a unique energy weapon found in several of the Fallout games, and is arguably the best weapon in the game, as you can one-shot almost anything with it.
The trade off is that the ammo you pick up for it is the only ammo available in the game.
That said, you can find ammo across all the aliens you encounter. I ended up with about 200 cells.
As a final note, the Alien Blaster will only appear in Fallout: New Vegas if you have the perk "Wild Wasteland". If you do not have this perk, you will instead encounter a different scenario, and find a unique variation of the Gauss Rifle.
Comment: Thanks. But it's kind of a bummer knowing there isn't any more ammo.
Comment: That it is. I always make a "back up" save immediately after getting the alien blaster in a fallout game. You can bet it will make a return in the new fallout, and the "no more ammo" rule is kind of staple for the weapon.
Answer: No.
Alien Power Cell –Fallout Wiki

The cells obtained from the captain are the only alien power cells in the game. Once they are used up, it is no longer possible to use the alien blaster, one of the most powerful energy weapons in the game, EVER again.


OFDM demodulation time

Question: How much time does it take to demodulate one OFDM symbol? In 802.11a standard the Symbol Interval Time is 4us. Does this mean that each symbol is demodulated within this period or there is pipelining involved? I understand that the answer may depend on the hardware platform, but I would like to know the range (us/ms) in the fastest implementation. Moreover, a breakdown of time needed at various steps would be nice.
Comment: You seem to be asking about latency (rather than throughput), but to get a meaningful answer, you need to specify what you consider the "start" and "end" of the specific process you're interested in. Certainly, pipelining is involved, and some of the pipelines associated with filters and channel equalizers can be fairly long. Also, once a "raw" symbol has been decoded, additional stages associated with error correction are used before you have the actual payload. Please clarify the specific issue you're trying to address here.
Comment: Thanks a lot for the reply. You are right, I am asking about the latency of demodulating one symbol. The 'start' in my process would be the end of the symbol period. And the 'end' would be the decoding of the raw symbol, before error correction.
Answer: Once you have the various I+Q samples, you need to execute an FFT. Plus other "cleanup" steps.
The Wikipedia page states 20MegaSamples/second for 4 us, thus 80 samples. Round up to 128 samples.
If I recall rightly, the computational load for FFT is 4 * N * log2N, thus 4 * 128 * 7 ~~ 3,500 operations. At 1 nanosecond per multiple/accum/butterfly, the time is 3.5uS.
https://en.wikipedia.org/wiki/IEEE_802.11a-1999
Comment: Thanks a lot for the reply. I have few confusions. Is computing the FFT time enough to estimate the total time? Moreover, is the "1 nanosecond per multiple/accum/butterfly" a practical assumption or just an example?
Answer: There is a lower limit to the time it takes, which is the 4uS it takes to collect all of the data. Obviously you can't start handling the symbol until all the data is in.
There is an upper limit to the time it is allowed to take in a conforming implementation. This is the turn-around time associated with ACK/NACK response. It will be specified in the physical layer protocol somewhere, but I don't know it off the top of my head, and am not about to go digging. At least you now know what you are looking for if you can access a copy.
In between those limits, any time is permitted, and, given the large number of different implementations using FPGAs, DSPs, and custom hardware that exist out there, you can be assured that most possibilities will have been covered.
A better question would be 'how much time does this particular implementation take'? A more meaningful question would be 'how many operations is needed for a symbol decode'?
Comment: Thanks a lot for the reply. I have been trying to find the turn-around time associated with ACK/NACK response as you have mentioned. Not much luck yet, but I will keep digging.

OFDM demodulation time


Mead and the balloon

Question: When my husband gets up in the morning, the balloons are deflated. When I get up 3 hrs later, the balloons are inflated. They stay inflated all day. It has been more than 3 weeks. Is the mead ready to rack? How do we know?
Comment: Why are you using balloons? Are you making prison wine? They are bi-directional, not uni-directional. So, bacteria in the air can get back into the must. Certain types of mead, especially chocolate recipes, will actually suck air back into the carboy and drain the airlock if you agitate it enough. Please invest in a proper airlock, or device a blow off tube (ie: have a tub from the top of the carboy run into a large bucket of sulfite-treated water).
Answer: This sounds like a common issue, If I were to guess your fermenting in a gallon or half gallon jugs? and where your fermenting your mead is in an area where the temperature fluctuates (by a door or window?). If this is close my suggestion would be to find a place where you think the temperature is Ideal and wont fluctuate put a thermometer there for at least 24 hours and check as often as you can or at least morning, day, evening, night. Short story short, consider your thermal mass (amount of liquid fermenting), and the temperature fluctuation where your fermenting. Basically your fermentation temp needs to be more constant then not (and at an appropriate ferm temp). Cheers and good luck

Mead and the balloon


Is it safe to cook food during a hike (on trail) when bears are possibly around?

Question: I'm going to the Rockies (trails in Jasper and Banff). Would it be safe for me to cook food while on the trail? Won't bears be attracted towards the smell of the food?
Comment: The Rocky Mountains are more than 5,000 km from north to south.  You need to be a lot more specific .
Comment: I don't understand the question. Are you talking about literally cooking in the middle of a trail, where people will have to step over your stove? Why would you not get off the trail? Are you asking about cooking as opposed to eating food that doesn't require cooking? I don't see why that would matter; I would think that a bear could smell either type of food. Are you asking whether it's even possible at all to go on a multi-day backpacking trip in the Rockies? Are you asking about whether it's better to cook near a trail than at some distance from the trail?
Comment: Would you be continuing on, after cooking, to a campsite?
Comment: @gerrit, I added locations
Answer: Many people travel for days or weeks in bear country. Several existing questions on this site address bear and camp/food related issues. If you've never traveled in areas with bears before, you should definitely give these a read:

What are the proper precautions/protocols for storing food while car camping in an area with bears?
What precautions should I take to protect myself and my camp from bears?
where is the optimal place to do dishes in the backcountry

It is recommended to cook and store at least 200 feet away from where you sleep. Assuming you'll be moving on after eating, as you asked "on the trail", then as long as you aren't stopping to eat in the middle of a frequently used camping location it should be fine. If actually cooking, as in pulling out your stove and not just eating a snack out of a bag, you should also be at least 200 feet from water and trails to minimize impact and follow Leave No Trace principles.
Bears are attracted to food, and you do need to take special precautions when you stop to camp to protect your food and the bears from each other. There are both legal requirements, such as use of bear-proof storage containers, as well as best practices, which depend on your location. If you want to know more about the specifics for the area you're visiting, I would suggest calling the relevant land management agency for wherever you'll be - e.g. the Park Service, Forest Service, etc.
Answer: I think part of the answer to your question relates to WHERE in the Rockies you'll be visiting.  Will you be in an area that is not visited much by humans, or will you be visiting a high-traffic area such as a national park or other popular tourist destination?
If you will be hiking through an area that has few or sporadic hikers, then you really have nothing to worry about.  Black bears, in most of the mountain west, are not accustomed to humans and their fear of man is firmly intact - especially in areas where they are hunted a little each year.  They do an excellent job at staying away from humans, no matter how yummy we might smell.  So fire up your stove and cook whatever you want.  Now, that being said, do take precautions.  Clean up after yourself.  Don't leave garbage in the woods.  Hang your food at least 100 feet away from your campsite.  (A few tiny bread crumbs on the ground won't matter; the mice, birds, and chipmunks will clean them up pretty quick.)  You'd hate to acclimatize a bear to humans and have it become a problem to others.  Someone, the bear included, could end up getting hurt.
I have spent a LOT of time in areas that have plenty of bears but not a lot of people: backpacking, hunting, fishing, dayhikes.  Sometimes I ate food that I'd prepared at home, while other times, I cooked in the mountains.  I have NEVER had a bear problem.
On the other hand, I have not spent much time in areas with lots of visitors.  In these areas, I would still cook my food, but I would be more cautious.  Bacon and foods that have tons of sugar in them are especially enticing to bears.  Go ahead and cook them, but then get them cleaned up ASAP.  NEVER store your food in your tent.  Be serious about hanging it at least 10 feet above the ground and more than 4 feet from any tree trunks.  Better yet, use a bear resistant container, if you can afford it.  Some campsites in high traffic areas have metal, bear-proof food containers.  Use them.  Especially in areas that might have grizzlies - anywhere near the borders of Idaho/Montana, Idaho/Wyoming, and Montana/Wyoming.
As an extra precaution, carry a canister of bear spray in a spot that is accessible - not inside your backpack.  Be sure you know how to use it.
Answer: I'll add to the existing answers by saying that the time of year likely does matter.  I've been the Canadian Rockies up by Banff and some of those trails are heavily traveled.  But, during the berry season (autumn), that doesn't stop bears from coming around even when you're not cooking something delicious.  If you talk to folks who have hiked up there a lot, they may have stories of close encounters.
If you're hiking around trails that are frequently used, you should cook far away from the trails so as not to unnecessarily attract bears to the trails.  If they are out roaming about in these areas (e.g. during berry season) they already exhibit some brash behavior and I would be careful about enticing them.
Answer: It is important to never let a bear get any of your food. Do not cook and eat in the open outside your shelter. You would be foolish to try to defend your food in the open. You can cure a bear from trying to steal any camper''s food if you cook and eat inside and give him a good dose of pepper spray. Your shelter should have a peek out vent on every side. Every side should be free to allow a hand with the spray can to be pushed under to get an accurate shot of spray in the bears face.
Comment: This is both wrong and not an answer to the question. Bringing food inside your test is exactly what you should *not* do.
Comment: Hi, this is good as general advice when camping with bears around. However, this question specifically asks about advices on whether one should be cooking during a hike when bears are possibly around. An answer is expected to be addressing this specific point. While *"Do not cook and eat in the open outside your shelter. You would be foolish to try to defend your food in the open."* tends to provide and answer, I personally think this can be made better to pose as an answer.


How can i add stylized cracks on my sculpture?

Question: How can i add cracks on my stylized game asset sculpture ? And how to get a good result without having to increase the polycount? Also how can i get a non-destructive workflow where i can continue to sculpt without the cracks and then edit the cracks?
Answer: Most artists are dragging an alpha of a stylized crack on their sculpture, you can find a set of popular alpha on the Gumroad page of Michael Vicente aka Orb here: https://gumroad.com/l/nOkHw
You will also need an high polycount to apply the alpha's details.
But the best way to apply cracks is by creating a mesh that you will use to cut your mesh with boolean, you will get more realistic cuts and non-destructive (with Modifiers and BoolTool brushes). You can use the BoolTool to work faster, you will have to select your crack mesh (completely closed) first then the mesh to cut and use the Difference operation.

If you use the Brush Boolean menu in the booltool you will be able to edit the cracks. Add an edge split modifier with a 30 degree angle to display your cracks correctly, sometimes the smoothing appears badly arround booleans.
Comment: "sometimes the smoothing appears badly arround booleans" - 30° edge split won't save you, there will be always a bad smoothing after boolean on low or mid poly curved areas on mesh. That takes a lot of work to clean up. Booleans on high-poly in Blender are very slow and not feasible. That's the reason to prefer those alphas or to do booleans in ZBrush or other apps. I also don't see why those slash marks are called "incorrect cracs" - there is nothing incorrect about them.
Comment: On low-poly booleans are fast, but they also destroy shading. You are misleading by only showing perfect examples on flat surfaces - booleans have to be cleaned if you want quality. If you add non-destructive into the equation and you want fast quality low-poly booleans you have only one option and that is to use Houdini.
Comment: I think you should post screenshot from Blender window, not from ZBrush. As you don't mention that, this might cause some misunderstanding.
Comment: Booleans are fast because we don't need to get millions of polygons to project the cracks details, you can even project a clean crack on a face with no subdivision. But Blender is slow in high poly and the drag stencil is very laggy and work well only on flat surfaces, using boolean is the only option for Blender users. Also with Boolean cracks applied as modifiers or BoolTool Brushes it is possible to edit them and have a non-destructive workflow.


Smallest PIC which the TCP/IP stack can be implemented

Question: What is the smallest (size) PIC with internal oscillator available which the TCP/IP stack can be implemented (and used) successfully? Also, what is the smallest (size) PIC with internal oscillator and Ethernet stack implemented?
Comment: You should define your question little bit more. For example by smallest, do you mean smallest footprint, cheapest or you refer to amount of ram?
Answer: If you're going to use Microchip's TCP/IP Stack, the PIC18 is the 'lowest-end' family of PICs that the software stack supports.
On their Ethernet page, Microchip recommends the PIC18F97J60. It has MAC and 10BASE-T PHY integrated.

IEEE 802.3 compatible Ethernet Controller
Fully Compatible with 10/100/1000Base-T networks
Integrated MAC and 10BASE-T PHY
Up to 128KB Flash
8 KB Ethernet Buffer
Support for Unicast, Multicast and Broadcast packets
Programmable wake-up on multiple packet formats,including Magic    Packet®, Unicast, Multicast, Broadcast,specific packet match or any
  packet
64/80/100-Pin TQFP Package
Comment: As far as I have seen both PIC18 and PIC32 families have the same minimum size, 10mm x 10mm x 1mm. Is there any other encapsulation with smaller size?
Comment: @Frederico So you're interested in the physical size of the chip (package). I couldn't say.
Comment: The chip may have an internal oscillator, but I think you need an external 25MHz crystal to get the required clock for the Ethernet controller.
Comment: @Robert that might be true but there is no sense put an internal oscillator that can't provide all the features that the microcontroller has
Answer: You may want to explore the ENC28J60.  It's an external chip from the PIC that handles all the Ethernet.  It interfaces to the PIC via SPI bus.  Just choose a PIC that has enough flash and RAM for the TCP/IP Stack.  You can download and compile to a simulator to see how much space things take.
Answer: On the link provided by m.Alin you can see in the right bottom corner a button named See all  Ethernet PIC MCUs which lead to here where you can see different characteristics, including packaging in the most right column. By the look of it, the smallest PIC32 with Ethernet are 64/QFN 64/TQFP
Comment: I couldn't find any one smaller than 10 mm x 10 mm x 1 mm, am I missing something?
Comment: Not sure if it is any help, but 64QFN have 9x9x0,9 mm. Albeit 10% shorter side it is still only a 1 mm difference and I have a feeling you looking for something much smaller.
Comment: as small as possible. I found the ENC28J60 which has a 5.3 mm of length and other encapsulations with 6x6 mm. I just don't know exactly what I can do with them, I mean, I just need ethernet, I don't need any other functionality of a PIC, so maybe that's the smallest CI I can find


In ASP.NET which event fires when page is loaded in clients browers?

Question: In ASP.NET which event fires when page is loaded in clients browers. Init, Load, PreRender event fires when page is not loaded in clients browser. Basically I have to some work when page is displayed in client's browser..
Answer: Instead of ASP.NET (server-side code) you might be more interested in Javascript (perhaps using jQuery's document.ready() which runs when the page has completed loading.)
Edit: The best answer I can come up with using only ASP.NET is OnLoadComplete()
Answer: There is no event like that. To understand why you have to understand how a web application works. The ASP.NET code runs on the server to build the contents of the web page, then the server sends the contents down to the browser which is running on the user's machine.
So the document being opened in the browser isn't even part of the ASP.NET page lifecycle. As far as ASP.NET is concerned, that page is now the browser's problem and it has already moved on to something else.
To make an analogy, it is like wanting to be notified when someone receives a letter that you (ASP.NET) mailed to them. Unless the recipient (the Browser) sends back some kind of communication there is no way for the sender (ASP.NET) to know what is happening somewhere else.
If you want to do something when the page is loaded in the browser, you need to write code that is run by the browser. Usually this is in the form of a script embedded in the page, usually in JavaScript.


Chromatic number of a graph with $10$ vertices each of degree $8$?

Question: I have simple graph G on 10 vertices the degree of each vertex is 8. I need to determine the chromatic number of G. I tried drawing and all but it seems there is a trick needs to be used.
Answer: Let $G = (V, E)$ be a simple graph like you described (which is unique up to isomorphism and known as the Turán graph $T(10, 5)$, by the way). Note that the maximal degree possible in a graph with $10$ vertices is $9$ and thus, for every vertex $v$ in $G$ there exists a unique vertex $w \ne v$ which is not connected to $v$ and the two vertices share a neighborhood, i.e. $N(v) = N(w)$. Therefore, $v$ and $w$ may be colored using the same color. This however implies that the chromatic number of $G$, denoted by $\chi(G)$, satisfies $\chi(G) \leq 5$ since we can take all such pairs $\{v, w\}$ as described above and assign every such pair a unique color (using 5 colors in total).
To see that $\chi(G)$ cannot be less than $5$ consider the (induced) subgraph $G'$ of $G$ that we get by removing one vertex of every such pair $\{v, w\}$ as described above (that means $vw \notin E$). We find that $G'$ consists of 5 vertices and is complete, therefore implying that $G$ contains a clique of size $5$ and giving us $\chi(G) \geq 5$.
Hence we have shown $\chi(G) = 5$.
Comment: Sorry, but I do not understand what you mean here. As I remarked briefly, $G$ is isomorphic to the [Turán graph](https://en.wikipedia.org/wiki/Tur%C3%A1n_graph) $T(10, 5)$ which has chromatic number 5.
Answer: Let $v$ be some node. then it had 8 neighbors, and there is exactly one node $u$ which is not connected to $v$. Notice that also $u$ has 8 neighbors, and thus $v$ is the only node not neighboring it.
We can partition the graph into 5 groups of 2 nodes $V_1=\{v_1,u_1\},...,V_5=\{v_5,u_5\}$, where every group's node's are not connected to each other (there is no edge $(v_i,u_i)$) but they are connected to everything else.
This is a 5-partition of the graph, and we can give a different color for each pair. Thus the chromatic number satisfies $\chi (G) \le 5$. But if we use less than 5 colors, say, 4 colors, then there must be two groups with a node that has the same color in both, but since that they are connected we get a contradicton to the coloring. Thus $\chi (G) \ge 5$ and finally $\chi (G) =5$

From here, it is a solution to the clique number, and not the chromatic number:
Since we have 5 groups, Then choosing one node from each group guarantees to give us a clique of size 5. So if we define $\omega (G)$ to be its chromatic number, then in this case we have proven that $\omega (G) \ge 5$.
Lets assume toward contradiction that $\omega (G) > 5$. Then there exists a clique of size at least 6. Let that clique be $\{w_1,..,w_6\}$. From the pigeonhole principle, we have  that there are two $w_i, w_j$ in the same $V_k$. But then there is no edge between them, in contradiction that this is a clique.
Thus $\omega (G) \le 5$ and finally combining those two together we have $\omega (G)=5$
Comment: The second part of this argument is not correct: the chromatic number is not a lower bound for the clique number of a graph. An example that demonstrates this is any odd cycle of size at least 5: They have chromatic number 3 but no cliques of size 3 (or larger). Also, the chromatic number of $G$ is usually denoted by $\chi(G)$ whereas $\omega(G)$ is used for its clique number.
Comment: to my understanding, its the maximal clique size in a graph... isnt it?
Comment: OHHhh i see..... i have misunderstood it
Comment: yea sorry i will fix it (even though its nice i found the clique number)
Comment: now its supposed to be correct (with the nice addition of clique number proof)
Comment: Your new answer is incorrect as well; the minimum degree of a graph is not a lower bound for its chromatic number. To see this, observe that a complete bipartite graph $K_{n, n}$ has minimum degree $n$ but chromatic number 2. But I first fell into the same trap, graph theory is hard :)
Comment: Oh you are right... Lol :0
Comment: Sorry for the confusion i had there... Now i hope its finally correct
Comment: As far as I can tell, it is (but the graph is 5-partite rather than bipartite).


What does "Passive" mean, when connecting to a server

Question: I'm using a client (AnyClient) to connect to a FTP server.  There's a checkbox specifying "Passive".  I can check this as Yes or No.  What does this mean?
Answer: Passive FTP is a method that assists you when connecting through firewalls or other security appliances. Since non passive (active) FTP connections require one connection from both ends, there is concerns with allowing connections in and out of the firewall on non-recognizable, higher port numbers that are used by active FTP. The return traffic from the client end will not be recognized upon the second connection, and is usually dropped. With passive FTP, both connections are initiated from the client end.
Most stateful firewalls today will deal with both methods of FTP very well since they are able to detect if packets are related to another connection.
Answer: It's FTP specific.
Active FTP means that the FTP server opens connections to the client for transferring data (downloads). This doesn't usually work too well with firewalls and NAT routers, so you can choose to use passive mode instead, where all connections are initiated by the client.
Answer: The FTP protocol has two connections.  A command channel, and a data channel.  In the original protocol (we'll call this Active FTP), the client will initiate the connection to the server on the command channel, then for any data passed, the server will actively create a connection back to the client. In the beginning, this was fine.
But then we got firewalls, which would block incoming connections.  And we also have NAT boxes on pretty much every home connection (and most work ones), which would block any incoming connections (well, unless you set your NAT to route beforehand, which is a pain in the ass). So, they changed the protocol some to allow the client to request passive FTP, which means for the data connection, the server is now passive, and the protocol handshake tells the client how to connect the data channel to the server.
It's a bit more work for the server, which now needs to remember which incoming connection is from which client (and therefore which command to answer to) but the only real way to get over the 'no incoming connections' rule.
TL;DR: Always select passive. Every server supports it, it will always work, and you never need to know why it will. Or just test the 'active' connection, if it works, mitzvah! If not, try passive.
Answer: This page claims to be the "Definitive Explanation" of passive vs active ftp.
The key difference between active and passive ftp is summed up at the bottom of the page:

Active FTP is beneficial to the FTP server admin, but detrimental to the client side admin. The FTP server attempts to make connections to random high ports on the client, which would almost certainly be blocked by a firewall on the client side. Passive FTP is beneficial to the client, but detrimental to the FTP server admin. The client will make both connections to the server, but one of them will be to a random high port, which would almost certainly be blocked by a firewall on the server side.

So with passive ftp you have to do a little more work on the server to allow connections on the high port number, but it should guarantee that any client can connect without problems as it knows which ports it has to open.
So if you have a server that will need to accept connections from a large number of clients passive ftp is the way to go. If you are only accepting connections from a small number of clients then active would be OK.


Blender crashes when rendering

Question: I've got a really big file to render, and I've played with render layers. But then I wanted to put everything back like it was before, to render everything in one piece, but now I have a problem because when I render the final object, the render doesn't stop. It says Freestyle:  Mesh loading 99% and no matter how long I leave it, it stays at 99% and after 15 minutes blender crashes. How to change that? I'm not sure how the render layers work right now, so I want to render everything at once like I did before.
Comment: It seems like you've hit the limits of what your computer can handle. Try breaking down the file in different layers and composite afterwards.
Comment: But before I've tried render layers, It was rendering fine..it just took really long, so I've tried render layers. But now when I want to change it back, it doesn't work anymore..And before that I've render with 100% resolution and 2500 samples..now I've just put 50% resolution and 100 samples and doesn't render till the end
Answer: When a render dies on Freestyle, it's usually a RAM issue. Freestyle takes a LOT of RAM (significantly more than Cycles for the same scene.) Once it runs out of your regular RAM, it will go into pagefile/virtual memory. This will slow your computer down to a crawl, because it's using your hard drive as memory. If it also runs out of pagefile space, it will crash. This is likely your issue.
The work around, if you were to attempt to still use freestyle, is to cut the scene down into more layers. Technically you can increase pagefile to give it more to work with, but even with a solid state drive this will be so slow as to be pointless.
Answer: Well I found out what was the problem..Accidentally I've activated Freestyle button in Render panel. Now that I've deactivated it renders as it should.

Blender crashes when rendering


How to include a new order status in between pending and processing in magento 2.1

Question: I want to include a new order status in between pending and processing.  i.e., after placing an order the status is pending and after this, I want to change to [New order status] and then processing status, when we click on a ship action, it changes. Suggest me, how to do this.
Answer: For this You need to create new status and assign it to State
go to admin panel Stores > Settings > Order Status
create  YOUR NEW STATUS
after that go to "Assign Status to State", here select YOUR NEW STATUS
and Set Order State "Pending" now save it .
so now when you will create new order then order status will be pending . after that you can view and changed it YOUR NEW STATUS


Water has H Bonds?

Question: So I'm studying for  a chemistry test and one of the practice problems is "What is the intermolecular force present in water?" We made handy flow charts for this and so I determined that it was polar. The next step asks me to use a Lewis dot diagram to find the shape; symmetrical means London Forces and Asymmetrical means either Dipole-Diploe or H bonds. Easy enough; it's bent, which would make it symmetrical, right? The answer key says it has H-bonds and that makes sense, but I concluded that it had London Forces because bent is symmetrical? What am I missing?
Comment: Whether it has symmetry or not is completely irrelevant. Everything has London dispersion forces but in some molecules they are masked by stronger interactions such as hydrogen bonds.
Comment: Even if it's the kind of bent where there are two extra electron clouds (which it is) that doesn't change the fact that it is symmetrical...
Comment: Strictly speaking, all: Lewis, dipoles, and H-bonding are present in water. I suspect that there's a item writing problem here (read=poor wording). If the question is about just IMF's, then all of them, if it asks for the $strongest$, then H-bonding.
Answer: Any answer to your question depends on speculations about what your "flow chart" specifically is. You seem to confuse molecular shape symmetry with H-bonding. There is no simple relation between them. HOH using Lewis octet rules, gives the O atom two lone pair and so a bent bond angle is predicted. This in turn would suggest that water has a large dipole moment and so is a polar molecule. This says nothing about whether the H atoms or the central O atom can hydrogen bond. Water has two planes of symmetry: all three atoms (by definition 3 points define a plane) are in a plane so are symmetrical about that plane, and the two H atoms are mirror images in a plane through the central O atom and perpendicular to the first plane I mentioned. But so what? None of this speaks to whether either the H or the O atom form H bonds. The ability of an H to form an H bond depends on the Z-H bond polarity, NOT the polarity of the entire molecule. (where Z is the atom the H is (covalently) bonded to). Some Z-H bonds, for instance in methane, the C-H bonds make the H atoms very unlikely to H bond. Consider the chlorite anion ClO2(-) we can correctly predict structure using Lewis dot rules, we can predict that it will be polar (not to mention being negatively charged), but what can we predict about each atom's H bonding propensity? Nothing as far as I can see. Will any of the 3 atoms H bond? Well, since it is negatively charged, I'd expect it will. So, which of the atoms will do so? Lewis structure and symmetry don't help, as far as I can see. What would your flow chart predict (and what is the correct answer) ? IDK.

Water has H Bonds?


.transfer question

Question: How does the transfer function behave? Was looking at a function I created, and saw that we transfer ether out of the contract, before deleting the data which determines whether or not it is allowed to. A lot of the code is hidden, because it's not really relevant.
Was wondering when does the transfer happen in user.transfer()? Let's say someone calls the function twice at the exact same time, so both calls enters the if statement, the user.transfer() are called twice, so the amount is transferred twice.
Afterwards, in the delete Bikes[_serialNo]; the call which is behind, will throw an error, because the information is already deleted. In the call, where delete Bikes[_serialNo]; throws an error, will the user.transfer still be executed? Or will it revert, hence eliminating the problem completely? If it was any other code, because of the error the whole transaction would be reverted and not executed, but does user.transfer() behave like that as well?
I know that I could just move delete Bikes[_serialNo]; over user.transfer, and there wouldn't be a problem, but it is more out of curiosity.
<code>func{
    //some code and checks whether the _serialNo, corresponds to a stolen bike etc.
    user.transfer(Bikes[_serialNo].insuredAmount);
    delete Bikes[_serialNo];
}
</code>
Answer:
Let's say someone calls the function twice at the exact same time, so both calls enters the if statement, the user.transfer() are called twice, so the amount is transferred twice.

This can't happen, because there is no concurrency. If two transactions are submitted, one will execute (fully) before the other.

.transfer question


Reliability and MTBF

Question: For an electronic device the the MTBF requirement is 4500 hours per year for 10 years, what does this MTBF mean and how to convert it into hours?
Comment: "hours per year" makes no sense here. If the client means he's operating the equipment 4500 hours per year and expects it to last (on average) 10 years, he may expect 45000 operating hours MTBF. Not 1.9 failures per year. Ask your sources to clarify the requirement.
Answer: MTBF means mean time between failures, so on average every 4500 hours there is a failure. This is for the first 10 years. Since there are about 365.25 * 24 = 8766 hours per year, this means an average of 8766/4500 = 1.948 failures per year.
Comment: @Winny ... from the Netherlands, and fixed (I should have known).
Comment: @RoyC Thanks, you are correct (and adapted the answer).
Comment: You from Germany? US English uses period comma instead of European (except UK) comma-comma.
Answer: The statement is rather ambiguous.  I think it says what the MTBF is supposed to be after 10 years if you operate the device for 4500 hours per year.  If so, that's a long-about way of saying the MTBF is supposed to be 45,000 hours.  Perhaps this is supposed to give some indication of both elapsed time and running time.  Some devices wear out due to time alone, but at a different rate when operated, so there is some sense to this.
MTBF means mean time between failures.  If you get a large number of devices, then on average that is how long each runs without a failure.  Conversely, if you get a large number of devices and run them for the MTBF period, half should have failed by the end of the test.

Reliability and MTBF


What Protocol is used in miner and Pool communication?

Question: I've been reading something about this, and I read about stratum, GBT, getwork. I wanna ask if what protocol are they using (HTTP?, TCP?). I am +1 to beginner so what I am asking now might be wrong please do correct me
Answer: Most use the stratum protocol which sends JSON data over a TCP socket. Some pools also support the getblocktemplate protocol which works over the JSON-RPC (i.e. it uses HTTP requests).