How can I ask single question across more than one stack?

Question: I have a question that I believe would be best served with collaborative input from multiple disciplines.  How can I ask a single question across more than one stack?
Answer: That's not something you should do. Each site has a specific audience so the same question is very unlikely to be answerable by multiple site audiences.
If you have a situation that may be solved by multiple sites then you should create a specific question on each of the sites, uniquely catered to that site audience.
For example if you wanted to create a fixed header on a Drupal website as part of the site template then you could ask a question on here about whether the logo should link to the homepage or not, then ask on GraphicDesign.stackexchange about what the colour combination between logo and background would be, and finally ask a question about how to integrate the template HTML/CSS into your Drupal website on Drupal.stackexchange.
The questions may all be related to the one issue that you have, but they are all separate questions so should be asked separately and to the right audience.
Further information about cross-posting questions can be found on the main meta.Stackoverflow website: Is cross-posting a question on multiple Stack Exchange sites permitted if the question is on-topic for each site?


Why bring steaks to room temp before grilling

Question: It is standard advice to bring steaks to room temp before grilling.  (Actually meat generally, and I absolutely agree w.r.t. roasts etc, but I am talking aout steaks on the grill here).
I like a pretty hard sear on the outside and almost rare inside ... well-rare as opposed to medium-rare.   I find it easier to do this (without ending up with well-medium) if I start with the steak at a cooler temperature.
Is this wrong?
Comment: Not if it's working for you.
Comment: It's a clever idea, but your doneness naming system is not well-known.  *Medium-rare/medium rare* does not describe two properties of the meat (outside and inside). It merely means that the internal temperature of the meat is between *rare* and *medium* (130–140 °F).  The idea of describing the exterior and interior with one term is interesting, but you should probably use language that doesn't overlap so much with the common doneness terminology.
Comment: America's Test Kitchen had similar success to keep the inside nice and rare.  They were even cooking frozen steak : https://www.cooksillustrated.com/how_tos/8741-the-science-of-cooking-frozen-steaks
Answer: Giving your steak a hard sear in a ripping hot cast iron pan (which usually is heavy enough to hold a lot of heat) probably takes a minute or two on each side. I personally find that throwing steak directly from the fridge into the pan, seasoning before I put it in the pan, will give me a sear no problem, but the interior won't have time to come up to the temperature I want - about 55-57 °C (130 to 135 degrees F)for medium rare, 49-51 °C (120-125 F) for rare. That's why I rest it for about 20-30 min before searing, during which I do my other prep work. If your method gives you the internal temperature you want, no problem.
I think you will get a steak that is cold in the middle though if it's too big, i.e., if it is heavier and thus needs more time to warm up internally, even in a very hot pan.
Comment: Sorry I should have explained this is using a gas grill which does not get to quite that heat.   I normayuly get my steaks 1.5 inches thick.
Comment: Temperature control on a grill is generally trickier, lttle easier with gas than charcoal. One problem here is that the only direct heat comes from the grate on the grill, the rest is hot air basically. Still, if you can make the steak as you like it and it's not cold on the inside, go for it.


Is there a difference between 'steigen' and 'steigern'?

Question: Are 'steigen' and 'steigern' alternative spellings, or is there some difference in meaning?
Comment: "steigern" is the so-called [Kausativum](http://de.wiktionary.org/wiki/Verzeichnis:Deutsch/Kausativ) of "steigen". So "steigen"="go up", "steigern"="make go up".
Comment: @Chris...why not make that an answer
Comment: @Emanuel: There are enough answers that give essentially the same answer as I would do. I only wanted to provide a technical term.
Answer: They are two totally separate verbs. Steigen means to rise, climb, ascend, soar, etc. whereas steigern means to raise, boost, augment etc.
Answer: An aspect not yet mentioned: *steigern" (increase somthing) is transitive, so you necessarily have to specify, what to increase. *Steigen" as in "Die Benzinpreise steigen" (the fuel prices increase) is perfectly happy without additional specification.
Answer: 1. steigen (Verb)
The word "steigen" is often used to describe a physical activity for climbing up somewhere.
For example: Den Berg besteigen.
However, there are several other possible usages for different scenarios.
2. steigern (Verb)
The most common usage for this Verb is in the sense of increasing or enhancing something.
For example: Den Umsatz eines Unternehmens steigern. or Der Sportler steigert das Tempo.
There are other possible usages.
I hope this helps. :)
Comment: Why are you using a completely different word ("besteigen") in an example to show the meaning of "steigen"? Even if the words are related, they do not necessarily have a related meaning, see for example "sitzen" and "besitzen".
Comment: Oh, yes. Thanks for the hint. I intended to write: "Ich steige den Berg hinauf."
Answer: No, they're not equal in meaning. Off the top of the head I cannot come up with an example where you can replace one for the other without changing the meaning. I'm sure there are some examples, though, since the two words have a tiny overlap. Sometimes you get a similar meaning with just a subtle difference:

Die Gehälter steigern: the act of increasing the salaries
  Die Gehälter steigen: the fact that salaries increase

Steigern in general mean: to improve, to get better/more/higher.
Steigen, in contrast, mean: to climb, to get on a higher level.
So, the only overlap is "to get higher" which is covered by the "salary"-example.


Is it possible to store air compressor filled without damage from water?

Question: I'd like to keep my air compressor filled for quick tire top-offs, like at gas stations.  The manual says to empty the tank after 4 hours.  How do gas stations avoid draining this often?  Is it possible with a consumer compressor?
Answer: Pressure tanks are usually steel, steel is somewhat flexible, it stretches a bit when filled, if the tank is left full it can shorten the life of the tank, I used to have a small scuba shop and did tank inspections as required annually, with hydrostatic testing every 5 years , the recommended pressure for long term storage for all tanks was 500 psi this is for tanks that range from 2200-3500 psi working pressure. I once purchased 4 steel tanks that had been sitting for close to 15 years at 3300 psi they were 3000 psi tanks, I dumped the air and had them hydrostaticly tested in fact all 4 tanks passed by enough to get the + rating that allowed them to get the 10% over fill. After that I did not pay much attention to that guide line but did tell my students the guideline and my experience so Can it be left full sure it may shorten the life of the tank , just make sure to blow the water out of the tank prior to letting it sit full of air.
Comment: Help how? You still have to drain it occasionally. What's more work, dragging your compressor around or spending 60 seconds draining it?
Comment: Does this apply at 120PSI, though?
Comment: Same thought after running the compressor, blow off the water in the tank, my 60 or 80 gallon 150 psi air compressor was purchased new in 2000 or 2001 it has been full almost the entire time, I always blow the water off the tank after running, I do this on my 5000 psi compressor that has 3 water separators it is amazing how much water is left in the tanks , if there is a lot of moisture the higher partial pressure of o2 in the air will rust out the tank faster even at 100 psi, there fore draining the water is important (and the reason SCUBA tanks require annual Visual Inspect procedure or VIP)
Comment: Would it help to pump up the tank inside in a relatively dry air-conditioned space?
Comment: After the tank cools I just crack the drain open and let out the water this actually provides a fairly low dew point, industrial dryers work on this principal the cool the air and the water condenses then it is drained, some go a step further and run the still humid air through a mocular sive , I know the spelling is wrong but a desiccant that removes additional water, then when that bank is full it is shut off and heated with dry air purge until it is dry again , the largest systems I worked on like that had 4 drying tanks after the Freon based cooler
Answer: That statement means after four hours of run time. Storing air doesn't cause water accumulation.
I'd drain it every few months if you only use it occasionally. The fact of the matter is that there will always be water in it, and when it rusts out you can't do much about it.
Industrial compressors have air drying mechanisms upstream of the intake air, so they mostly eliminate the problem. Either that or they drain them nightly.
Comment: We do have air dryers prior to our holding tanks but even the large tanks have float type water dumps or electronic timers at the bottom of each tank.
Answer: Automatic blowdowns
This taps the bottom of the tank where water would accumulate.  At intervals, it blows some air out of the tank. PSHHHHHT!  This ejects most of the water and some air.
This operates at time intervals, when the compressor cycles on or off, or when water is detected.
Your electric bill will not like this
In real world practice, compressors are not leakproof. It will cycle randomly at all hours.


Gratuitous use of magic: poor writing and/or unenjoyable?

Question: Many of my characters, main, side, and recurring all have a suite of magic abilities. So will them constantly using magic be annoying? Will it make the magic stale? What tips should I follow and what should I avoid?
Comment: Rowling certainly seems to have figured out the recipe; make everyday magic seem like exactly that. Don't have the characters draw attention to anything they're doing with magic that would seem ordinary to them. The more spectacular or difficult stuff, sure, go into some detail including character reactions, but pulling out plates or silverware from the drawer with a wave of a hand or wand, just say they do it and move on. This may require, as in Rowling's universe, not using magic in front of people who don't know magic exists.
Comment: It all depends on how talented the author is.
Comment: Is this low-level magic like turning on lights and staying dry in the rain, or high-level magic like teleporting to work to avoid traffic?
Answer: You might want to check out Brandon Sanderson's Laws of Magic. His tips were a great thing to consider when I was writing my story.
They are in summary:

An author's ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic.

This means that if magic is used often, the mechanics of it need to be well understood by the reader, and if magic is used rarely then there's no need to go into in-depth explanations.

Limitations > Powers.

Interesting characters are made by what they can't or won't do, as opposed to what they can and will. Omnipotent beings rarely make interesting characters.

Expand, Don't Add.

It's better to have people with a few well-known and understood magical abilities than people who can do anything they want.
These are obviously very much shortened, he goes into a lot of detail on these points, so the links are well worth a read.
You can obviously choose not to follow these points, and in order to create a work of fiction that is unique to you then it is likely that you will need to break these rules somewhere, but I'd say that it's a great jumping off point.
Comment: The "Limitations > Powers" point is probably the single thing that will keep the OPs use of magic from feeling like a "Deus Ex Machina". If magic can solve any problem, what's the point of reading the book if all conflict is resolved by literally waving a wand?
Comment: This is the truth, gratuitious use of magic isn't annoying, gratuitious cognitive load is. So as long the use doesn't require the reader to understand something new without improving the story, there is no problem.
Answer: My largest magic pet peeve is when a character uses a previously unintroduced magic for every sticky situation they find themselves in. So, if a character has to defy death 10 times, and then they have 10 unique ways to get out of the death trap and the reader has never seen that magic before that comes across as a lazy author using magic to keep a character from suffering any actual detriment.
Magical surprises are okay, but not an array of new ones, especially at just the serendipitous last minute.

A character shouldn't always be able to rely on magic to solve problems
A character should have a predefined list of magical talents, and then stick to those... UNLESS, the story involves learning new ones
sometimes a character has a magical ability to disarm a bad situation in a subtle and elegant way, but many authors will write a lavish and dramatic magical moment to show off the awesome magicalness of magic magickery.
Characters that can use their one trick, but in a variety of ways, are very interesting magical characters because they show cunning and skill instead of always being lucky or being perfect without having to try
magic characters necessarily will have a trade off with their magical skill. What regular-joe type of thing does this magical character not know about or had to learn because they're magically gifted? How does the lack of those every day sensibilities hurt the character? How do they make up for it?
Magic shouldn't be used to keep your character from harm's way, or to keep them from having to develop as characters
Magic should also allow the character to develop in ways that non-magical beings couldn't
The character's magic has to have limits in strength and endurance. You don't always have to show us the limits, but the reader needs to know that the character could suffer if they're not well matched to the task.
Also, it helps if there's some code to how the magic works... even if it's not clear at first or loosely defined. It's more fun to know that magic has a back story and a root, instead of being an omni-present force with no internal mechanics
I'd say create some rules for how magic in your world works, and bend them when you want or need to, but don't break those rules without very good reason. You don't have to tell the reader what you're rules are.
If your magic does have rules, it is sometimes more fun if the reader has to slowly learn what the rules are by reading how magicians follow or break the rules. Much better for the story than putting all the rules in a single expository chapter; that would get boring.

This is all I can think of for now. Good luck!
Post your finished work if want.
Comment: All for it. People tend to do the easiest thing at hand. I would totally magic the hell out of dishes if I could. So I say go for it.
Comment: @JustinAlexander Mage who always magics the dishes: character trait. Remove his ability to do dishes with magic: interesting conflict. Does he pout? delegate? brain-lock? grit his teeth and wash by hand?
Comment: So what do you think about a character using an ability often for mundane things just 'cause they feel like it/it's easier/that's the kind of person they are?
Answer: The main way to make magic "not annoying" it to make sure it follows the rules of magical physics, if you will.
Magical acts require energy (fuel). The energy has to come from somewhere to be expended in an act or a spell. It can be extinguished and replenished. It's not endless.
Magical acts have consequences beyond the immediate result. Shooting something with a levinbolt will also raise the ambient temperature in the room and temporarily blind onlookers; using sound waves will burst eardrums.
Even people born with magical talent have to learn how to use it: how to cast a spell, direct energy, form a shield. It takes time and effort to learn these things.
Just because everyone has magic doesn't mean that they'll use it for everything. There will be times when it's easier, safer, or quieter to do something by hand.
For homework, read the Harry Potter series, play some D&D or read some of the D&D/Forgotten Realms etc. novels, and watch the BBC show Merlin for starters. Mercedes Lackey has about two dozen sword-and-sorcery books which show the learning process and consequences of magic in great detail.
Answer: IMHO, characters who have magic powers are tricky, because:
(a) If the character can solve all his problems by just waving his magic wand, the story is boring. Problem comes, the hero waves his magic wand, problem solved, end of story.
(b) If the character doesn't solve his problems with his magic powers for no apparent reason, as a reader I just wonder why not. Like I know Tolkien was wildly popular but I found his stories boring and frustrating. Why couldn't Gandalf just use his magic to destroy the rings? Or magically teleport them all to the place where they could destroy the ring rather than having to make a long and tedious trip? All the problems the characters faced in the stories: why couldn't they just fix them with magic?
Sure, you could say, Well, magic doesn't mean the character can do ANYTHING. He's not all-powerful. Well fine then, you have to describe to me just what he can and can't do. Otherwise it sounds like you're just making it all up as you go along, letting his magic powers get him out of situations when that's convenient for the story and not being of help when it isn't. Frankly, I think a lot of authors of such stories DO just make it up as they go along.
Which leads to (c) You say how amazingly powerful this person is, and then you have to start coming up with limitations of his power. Often this seems very contrived. Like I always found Superman stories rather contorted: first they tell us how he's super strong and can fly and all these amazing powers that make him invincible. But then no enemy is any threat. So they have to come up with "kryptonite" to give him a weakness.
Not to say that it's not possible to write stories about people with magic powers that are interesting, just that there are pitfalls.
Comment: Eddings, a frequent best seller, has the character UL as an all-powerful god, but he chooses not to intervene. I would also add the show LITTLE CHARGERS (Nickelodeon) to the list of good views (I'm serious!). They bumble their spells and then have to get rescued by stronger spells, which can run itself in circles.


What chords should accompany descending bass notes in a scale?

Question: Using the key of Bb for example. In a bass walk down and starting from Bb and descending from Bb the sequential descending bass notes are A, G, F, Eb,D and finishing on F. Now if l used Bb Major, A minor, G minor, F Major, Eb Major, D minor, F Major - it doesn't sound as good as Bb Major, F/A, G5, F5, Eb5, Bb/D and F5! The question is why does the latter sequence sound better? Can anyone explain why this is so?
Answer: It might sound better to you, but won't to everyone! And if the first set of chords was to be voiced differently, it might sound 'even better'.
It's unusual that a chord sequence will follow a walking bass line chord for note. Yes, it does happen, but more often the walking bass line is four notes to each chord.
The 5 'chords' may have a slightly better fit with the genre in question, and they also take away the maj/min feel of each chord. Both slash chords are first inversions, which again may suit the genre better. There are literally hundreds of combinations for this sequence, and I'd be surprised if you'd tried them all. Listen to some others, then decide.
Answer: In academic circles we call this a "step-descent bass," and there are a few common patterns from the classical tradition. (I know you may not be interested in that musical tradition, but you can always snag some good ideas from it!)
Here's an excerpt from Fauré's "Pavane." Note how he just uses descending root-position triads: F♯ minor, E major, D major, C♯ major. (But he spices it up a bit; these chords appear in the first halves of the measures, and he puts intervening chords in between them.)

And here's an excerpt from a famous Rachmaninoff prelude; the step-descent bass begins in m. 3. In Roman-numeral notation, the chords he uses are i–III64–iiø43–V.

In addition to these, the other very common pattern is I–V6–IV6–V.
In your key of B♭ major, these progressions would be (and I'll take some liberties with chord qualities):

B♭–A♭–G♭–F
B♭–Dm/A–Cm7/G–F
B♭–F/A–E♭/G–F

As for why you don't like your original choice of B♭–Am, it might be because of the presence of E♮ in the second chord. But if you change that E♮ to E♭, suddenly you're playing an A° chord, which would also be pretty rare in this still. Try playing the second chord as A♭ and seeing what you think.
Answer: In more concise terms, the main reason your first progression doesn't sound right is because of the A minor chord. A minor chord has the notes: A, C, E.
E nat doesn't fit into the key signature of Bb, the chord you would be using (if 'restrained' to the key of Bb) is A dim.
A chord progression you could always try is Bb, Dm, Gm, F, Eb, Bb --> F. (with the bass notes you have spoken of).


Interconnecting two networks connected by two linux routers on Raspberry Pi

Question: I have a peculiar problem as described below.
Two sites with a linux (Raspbian Jessie Lite) based routers each having network as stated below
Site1
Raspberry Pi Router 1
eth0 192.168.1.101/24
eth1 192.168.230.1/24
Computer1 connected to above router with address 192.168.230.103
Gateway is 192.168.230.1
Site2
Raspberry Pi Router 2
eth0 192.168.1.102/24
eth1 192.168.231.1/24
Computer2 connected to above router with address 192.168.231.103
Gateway is 192.168.231.1
Router 1 configuration
/etc/iproute2/rt_tables on Router 1
.
.
.
1     eth0
2     eth1
/etc/network/interfaces file on Router 1
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
allow-hotplug eth0
auto eth0
iface eth0 inet static
hwaddress ether b8:27:eb:89:27:4f
address 192.168.1.101
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
up ip route add 192.168.1.0/24 dev eth0 table eth0
up ip route add default via 192.168.1.101 dev eth0 table eth0
up ip rule add from 192.168.1.101/32 table eth0
up ip rule add to 192.168.1.101/32 table eth0
allow-hotplug eth1
auto eth1
iface eth1 inet static
hwaddress 00:e0:4c:53:44:58
address 192.168.230.1
netmask 255.255.255.0
network 192.168.230.0
broadcast 192.168.230.255
up ip route add 192.168.230.0/24 dev eth1 table eth1
up ip rule add from 192.168.230.1/32 table eth1
up ip rule add to 192.168.230.1/32 table eth1
I also applied IP Forwarding through following commands as a root user
echo 1 > /proc/sys/net/ipv4/ip_forward
Also, in the /etc/sysctl.conf file , I set net.ipv4.conf.all.forwading=1
Configuration for Router 2 is exactly same with appropriate addresses set.
In effect, the setup is
Computer1<------>Raspberry router1<------->Raspberry Router2<------> Computer2
Configuration is a simple lab setup without internet and NAT
Problem
From Computer 1, I can ping router 1 interfaces 192.168.230.1 (No problem) and 192.168.1.101 and I can ping Router 2 interface 192.168.1.102. But I cant ping the LAN side interface of Router 2 that is 192.168.231.1 and obviously, I cant ping computer 2 at 192.168.230.103. Same problem occurs from Computer 2. Both Computers run Ubuntu 16.04 LTS.
I alternatively also tried adding routes on each router (Route of Router 1 specified below)
route ip add -net 192.168.1.0 netmask 255.255.255.0 eth0
route ip add -net 192.168.230.0 netmask 255.255.255.0 eth1
route ip add -net 192.168.231.0 netmask 255.255.255.0 eth0
However, the result is the same. Can anyone give me working configuration for the same.
Thanks and regards in advance
Answer: Your routes are missing a Gateway. The Routers do not know how to reach the LAN network of the other router.  Specifying only the device as you did is not sufficient as there are 253 possible gateways to reach the other LAN.
Try setting a route on Router 1 like this:
route add -net 192.168.231.0 netmask 255.255.255.0 gw 192.168.1.102 dev eth0

On Router 2:
route add -net 192.168.230.0 netmask 255.255.255.0 gw 192.168.1.101 dev eth0


Where did the term "garage band" originate from?

Question: Apart from the video game, the term has been in use amongst musicians for years - where did it come from, documented listings?
Comment: Uh, from wannabe rockers playing in garages?
Answer: As Robusto comments, it's probably just an obvious turn of phrase that could easily have been "re-coined" repeatedly.
As Google NGrams shows, the term had no real currency until the 1980's, but that certainly doesn't mean such bands didn't exist (see this site).
Personally I think that it's quite possible many parents of wannabe rockers (esp. perhaps West Coast Americans) may have used it to describe what their kids get up to on the weekend, even back in the 50's. But it didn't really gain traction until the post-punk era, when the type of music associated with it started to become commercially significant.
Comment: @Mari-Lou A: Nah. I'm not *that* into "garage bands", and I'm pretty sure the term originated in the US, but I'm also pretty sure I was familiar with the term long before the millennium. Besides, even after discounting the misdated entries in my NGram, it's obvious it was being used freely by the 80s.
Comment: The Google Books hits available from NGrams shows the term first being used in publications in 1976 (Stereo Review, Rolling Stone, Mother Jones).  Although it may have been coined and died several times before, I think mid-70's is indeed when it came into any noticeable use.
Comment: The site you mentioned was set up in 2002, it could very well be the owner(s) coined that title, *60s garage bands*, for commodity.
Comment: I didn't mean to imply the expression, *garage bands*, was created in the noughties just that the "word" didn't exist back in the 60s. Although Tokyjose found a reference dated 1971
Comment: I would guess that I first heard the term used in the 70s.  The meaning was immediately obvious to anyone hearing it.
Answer: Garage band
The first documented reference I found with the modern meaning is from 1975's Stereo Review, Volume 34:

There's many more 1976 examples:

Mother Jones: "Sounds pour in from surrounding areas: the tabasco-hot rhythms of Clifton Chenier, Lightnin' Hopkins's gritty Houston blues, Flaco Jimenez' polka-powered Tex-Mex con/unto, or a teenage garage band that dresses in cowboy drag simply for ..."
Rolling Stone: "The B-side 'Off The Hook' is a great mid-tempo garage band song with a shuffle beat and one of many Jagger, Richard compositions concerned with hard-as- nails teen queens. "
High Fidelity Musical America: "His rhythm work on "Jump on It" is merely of the garage-band variety, and those songs that could have proved passably interesting inevitably flounder. "
Rolling Stone: "... the local equivalent of a garage band began to play an almost perfect carbon copy of "In the Midnight Hour.""
Stereo Review: "Although practically every garage band in Christendom tithes (spiritually of course) to the King, his influence on Bob and the Mop Tops is perhaps the most clearly documented, not only in living memory but in the rock press, ..."

(There's a possible listing of a band called Tom and Jerry Smith's Garage Band in a 1971 JEMF quarterly, but this can't readily be confirmed, nor whether it's related to practising in a garage. There was also a Smith's Garage Fiddle Band, also known as Smith's Garage Band, who recorded in 1928 but we can't easily link this to the modern usage.)

Garage rock
How about the related garage rock? A 1978 Billboard announces the opening of the Paradise Garage Rock 'N' Roll Club:

There's more examples two years later in 1980:

Stereo Review: "Don't, in other words, hold your breath until, say, the Masses of Josquin des Prez reach videodisc, and don't expect to see any fresh-from-the-garage rock groups so honored either."
Billboard: "The store carries vintage rock and current new wave, with a strong emphasis on tough, energetic "garage rock.""
Contemporary Music Almanac: "Australians AC/ DC play garage rock at excruciating volume with a self-parodying pan-ache epitomized by guitarist Angus Young's schoolboy-gone-mad schtick and original songs like "Rock 'n' Roll Damnation" and "She's Got Balls"."
Answer: Garage band -- revisited
The earliest examples of the term "garage band" that I could find are from two articles printed in Rolling Stone magazine in 1971:
1) "The Faces" Album Review by John Mendelsohn, Rolling Stone, March 1971:
"On the former the group is content to faithfully recite the original arrangement, which act, in these dark days of Blood, Sweat & Tears, Keith Emerson, and every last punk teenage garage band having its Own Original Approach, is awfully refreshing."
Read more: http://www.rollingstone.com/music/albumreviews/long-player-19710318#ixzz2ZwTptbut
2) "The Grateful Dead" Album Review by Lenny Kaye, Rolling Stone, November 1971
"It can't quite be called bad, since it's pretty clear that the Dead have progressed so far beyond your average garage band that there's no danger of them ever slipping back, but it still can provide a bit of a letdown for those who have come to expect only great things from the grate."
Read more: http://www.rollingstone.com/music/albumreviews/grateful-dead-19711111#ixzz2ZwU66zos
(The second reference is particularly interesting, as it's written by Lenny Kaye, who would produce the 1972 compilation album, Nuggets, which is typically cited as the album that kicked off the garage rock revival. By the late 1970s, the term "garage rock" would come to refer to this particular brand of 60s rock and roll, although the Nuggets album does not use the term at all--confusingly referring to the bands featured in the album as "punk rock". Of course, punk rock would eventually come to refer to an entirely new, still burgeoning genre of rock music.)
Comment: +1 for research and for finding the earliest recorded document of "garage band" (so far).
Answer: The Clash's self-titled debut album released in 1977 features the track Garageland with opening lyrics,

We're a garage band/ We come from garageland.

Though not the first published reference of the term garage band, it is a significant example of the popularization of the term.
The inspiration of the song as recounted by Joe Strummer[1]:

...After our second gig a critic in New Musical Express wrote that we
  should be returned to the garage and locked in with a motor running so
  that we died. "Garageland" is about that. I was trying to say that
  this is where we come from and we know it, and we're not going to get
  out of our depth. Even though we've signed with C.B.S. we aren't going
  to float off into the atmosphere like the Pink Floyd or anything.

[1] Coon, Caroline (1977). 1988: The New Wave Punk Rock Explosion. London: Hawthorn. ISBN 0801561299. OCLC 79262599


Can a sharingan be regenerated?

Question: I remember that Naruto healed Kakashi's eye. If he did that to Sasuke if he lost his eye, would the Sharingan regenerate along with his eye, or would he be left with just a regular eye?
Comment: Naruto didn't "healed" Kakashi eye but made another from his cells, it's not good example for your question.
Answer: By "regenerated" you mean like Sasuke could get his rinnegan back after Boruto stabbed it out then no, But if you mean if kid Kakashi had a Sharingan, and then got his eye slashed then yes. What I mean is that if an eye is slashed and not stabbed out, a strong medical ninjutsu specialist could heal it.

Can a sharingan be regenerated?


Keeping fingers close to frets when playing barre chords

Question: The problem I am faced with while playing a barre chord is that the finger i use to make the chord behind the finger that's barring has to be place very far from the fret so the sound it makes is always muttered.
Is there a way to avoid it ?
Comment: Help ! what chord, what fret is it, please?
Answer: Although you are referring to barre chords (E Minor "shape", by the look of it), I think of this as being the classic "A-chord-problem".
Often, one of the first chords a guitarist will learn is A (finger 1, fret 2, string 4; finger 2, fret 2, string 3; finger 3, fret 2, string 2), and although this is quite a basic chord, and a simple shape, it is actually quite hard to play. Why? Because you have to squeeze all three fingers onto fret 2 on adjacent strings. So, it is really hard to get the first finger note to sound well, as it is further from the fret. You often have the same problem with the kind of barre chords you are playing here.
For your chord, you need to do two main things to make the third finger note sound as good as possible:

get the third finger as close to the fret as possible. You can do this by straightening it a little, so it "pushes" towards the fret. You can also get it closer to the fret by having it as close to the fourth finger as possible; these two fingers can be pressed together, with the third finger almost curved over the fourth finger, so that they almost work as one "unit". (This works well with finger three and four because finger three is just the right length to curve over the fourth finger.) You'll often also find it useful to move between barre chords keeping these two fingers locked together as a unit.
Apply a little more pressure with finger three than with finger four. You can help to do this by pushing your wrist forward just a little.
Comment: But ur not using the fourth finger?
Comment: Aren't u referring to the pinkie?
Comment: Hello @user139024. It's hard to tell which fingers you're using on your picture. I assumed you were using 1 for the barre, and then 3 and 4. If instead the fingers showing on your picture are 2 and 3, I would use 3 and 4 instead - this will make the chord easier.
Answer: As I've got older, my fingers have got fatter - or the fingerboards have shrunk. So, with the 'A' shape in particular, at the nut end, I may use middle/ring/pinky, by 5 or 6 fet I've only put 2 fingers on strings 2,3 and 4, and by about the 9th fret, it's ring finger across 2,3 and 4. Yes, all 6 strings sound clear (I tend to barre bottom also), and it's a lot more comfortable.
Answer: It is hard to tell without seeing your whole hand and arm, but I would say that problem could be avoided by lifting the guitar neck as much as needed and repositioning your wrist. Many people tend to play with the wrist laid back and then the fingers seem to be not long enough. In particular folk and rock guitar players tend to play with the guitar neck lower than they should therefore limiting their reach and risking tendon injuries.
When playing chords that need wide stretches there are two main things that can help. First, most of the times finding the right position for your wrist and thumb (thumb might also be positioned too high or too close to your barring finger), and second stretching exercises.
One good stretching exercise I have been doing almost daily for many years is:

Position your left hand fingers

Pinky on 1st string, 12th fret
Ring on 3rd string, 12th fret
Middle on 2nd string, 11th fret
Index on 4th string, 11th fret

Play an ascending arpeggio once SLOWLY! (8th = 70 Beat per minute with your metronome)
Slide your index finger to the 10th fret and play an ascending arpeggio again
Slide your Middle finger to the 10th fret and play arpeggio again.
Slide ring finger to 11th fret and play arpeggio.
Slide pinky to 11th fret and play arpeggio.

Repeat the process moving one more fret to the left, and continue to do it until your index reaches the 8th fret, and then go back sliding your fingers to the right in reverse order. If at some point you feel like you are stretching too much then don't go that far. The 8th fret is normally a good initial limit unless your hands are too small.
Do this exercise a couple times a day. After a few weeks (I would say 8 to keep it on the safe side, although supervision of a trained teacher is advised) you can go to the 7th fret, but always being careful of not stretching too much, and not applying too much pressure on the fret board. Just enough to keep the notes sounding good and not even a tiny bit more. If it doesn't feel comfortable you are going too far.
You can progressively go lower, but I wouldn't recommend it without professional supervision. I normally don't go under the 5th fret.

One trick to reduce stress on your barring finger that could also help to increase your reach, is to place your barring finger on the strings in a way that your articulations fall on top of a string. If you choose to use mostly the fleshy part of your finger you will need more pressure, which will lead you to place your thumb closer to the barring finger.
Hope this helps.
DP


Export/Import Glabal term store

Question: We are migrating Global term store from SharePoint 2013 to SharePoint Online. Can i get the scripts to export term store from SharePoint 2013 in a text file and then import that in SharePoint Online? We want to upload/download using CSOM script.
Answer: You can use PowerShell command to export the term store in SharePoint 2013 into CSV file, and then import to SharePont Online.
More information and PowerShell command check the article:
PowerShell for SharePoint 2013: Export TermSet to CSV
Migrate SharePoint 2010 Term Store to SharePoint Online with PowerShell

Export/Import Glabal term store


What are good options for hosting video that give you privacy and control (not youtube or vimeo)?

Question: I have used http://www.longtailvideo.com/bits-on-the-run,http://www.influxis.com/, wistia for video hosting. Wistia didn't allow the finer control that we wanted to have. Influxis doesn't have the features that Bits on the Run has but platform usage for BOTR gets expensive. I was thinking of moving the videos to Amazon CDN. What are your thoughts and experiences with video hosting and are there any recommendations? Videos will be privately streamed to 100's of doctors offices.
Answer: Not all of these apply, but you could also take a look at these:

livestream
Ustream
justin.tv
blogtv
vodpod
hulu (ent)
kaltura (foss|commercial)
metacafe
monetizemedia
Brightcove
Kyte
BestTV (--Brightcove reseller)
vbrick (--ent)
kit digital (ent)

These are from my personal notes. The "ent" means the service is aimed at the enterprise market only; "foss" means it's Free and Open Source Software; and the "--" just means I didn't like the site much.
Answer: If you don't mind paying, there's always Vzaar. Last company I worked for used them a lot and it didn't seem too expensive.


Use ethereum address from ledger nano S for participating in ICO

Question: I want to know if I can use the ethereum wallet addresses that come with the Nano S. I have eth on it and used this to participate in an ICO. Is that ok as it is first time using this address as it doesn't have a private key?
Thanks
Answer: The list of all supported ERC20 tokens by the Ledger Nano S is at this page
I'm not quoting this page because it is often updated, therefore my quote would be quickly missing important information.
If you just want to receive some ERC20 tokens you actually don't need to do anything special. Every Ethereum addresses have the same properties, no matters what wallet you're using.
With the Ledger Nano S and the Ledger App you won't be able to manage (to send) some non-supported tokens but don't worry, it doesn't mean you lost them. They are still there and you can check it by viewing your Ethereum address on etherscan.io for example.
In order to send non-supported tokens you must connect your Ledger Nano S to MyEtherWallet as described here


Do I require a South African transit visa when traveling to Botswana?

Question: I'm Algerian citizen, traveling to Gaborone Botswana via Johannesburg (Algiers-Doha- Johannesburg-Gaborone). Do I need South African transit visa?
Answer: Per TIMATIC, the database used by airlines:

Visa required, except for Passengers transiting through Cape
  Town (CPT), Durban (DUR), Johannesburg (JNB) or Lanseria (HLA)
  with a confirmed onward ticket for a flight to a third
  country.

So if Doha-Johannesburg-Gaborone is in a single booking, you do not need a visa.


What does Yuuma want to do on Earth?

Question: I want to know what does Yuuma want to do on Earth. Wherever I see it, it's not full episodes so I couldn't see if he knew he was dying, or there are other reasons he came to Japan?
Answer: Yuma is a Neighbour form another world.
He comes to Earth (also named otherwise in the multiverse used in World Trigger) searching for a friend of his father.

as his father gives up his life to save Yuma, granting him a constant trion body and producing a black trigger at the same time, Yuma remembers his father speaking very fondly of a "friend" on Earth, which he helped to turn away other neighbours...
Comment: FYI, you can hide spoilers but putting ">!" before the appropriate section.
Answer: Yuma comes to Japan not only because his late father told him so

But also for his personal reason:

 He wants to resurrect his father

Sources: Volume 3 Chapter 18 & Chapter 20

What does Yuuma want to do on Earth?


Electronic voting UI - got any (good) examples?

Question: I can't seem to find any screenshots of (preferably good) electronic voting systems. I mean the kind that's used in elections. Any ideas where I can find one?
Comment: This is not a question that can have a definitive answer in the format we're looking for here. Please rephrase.
Answer: If you want to read research on and analysis of the design of user interfaces for voting systems, I recommend reading the work of Mike Byrne (at Rice), Whitney Quesenbery,
Dana Chisnell,
Ben Bederson (U Maryland), Juan Gilbert.
Also, you can take a look at Votebox, Pvote, and Prime III, which are research voting systems that you can run and take a screenshot of.
I can also highly recommend the Usability Professionals' Association Voting and Usability Project.  They've done some great work on usability of voting systems.  Between the above resources, you should be able to find a great deal of information on UIs for voting machines.
If you really just want some screenshots, googling the name of the voting machine should find you screenshots.  Some popular electronic voting machines include Diebold AV-TS, Diebold AV-TSX, Sequoia AVC Advantage, Sequoia AVC Edge, Hart-Intercivic eSlate, ES&S iVotronic.  Verified Voting has a guide  to the most widely used electronic voting machines that may be helpful.
Comment: Thanks for the wonderful links and info! Very much appreciated :-)
Answer: Please note that in the context of elections, all electronic voting solutions have one important drawback: they obscure the process that by the very nature of it should be as transparent as possible. It becomes impossible to follow your individual vote and see that it is handled correctly, while still keeping that vote anonymous. At least, not without very complicated technical solutions. That does not really add transparency, as the point of the transparency is that the average voter can understand and verify the process.
No user interface, no matter how sophisticated, will solve this basic problem.
Comment: I would rephrase that as 'all _deployed_ electronic voting solutions'. There are some excellent solutions that have been offered that meet all the needs of a secure, verifiable, and anonymous voting system. 'Not in use' is not the same as 'doesn't exist'.
Comment: If you can point me to one that is also _understandable_ by a lay person, I'll make the edit. So far, the ones I've seen rely on complicated cryptographic schemes, and to me, that defeats the purpose.
Comment: [This paper](http://www.constitution2.org/wiki/files/2004_chaum_secret_ballot_receipts.pdf) covers a voting method that is essentially impervious to malicious manipulation, even if the software or the results afterward have been tampered with. While *why* it works is not obvious, the fact that it does without any trust needed in any portion of the voting system can be proven. Bad software or malicious intent will be found, provably.
Comment: I'd like to note that the above method allows users to be sure their vote was counted (and to prove they voted), without the possibility of voter coercion. The receipt cannot provide who they voted for without the other half.


Animal equivalent for "as _________ as humanly possible"

Question: Phrases like, "as fast as humanly possible" are pretty well understood, but what about when you're not talking about a human? A dog can run faster than a human, for instance. How would you express that a dog arrives as quickly as can possibly be expected of a dog? Perhaps a rabbit can't get as close as a human can to say, a high shelf. Is there a way to fill the blank, in that example, for "as close as _________ possible"?
Comment: He was as determined as doggedly possible. She was as snide as cattily possible. He was as suspicious as fishily possible.  She was abashed as sheepishly possible. He was as clever as foxily possible. She was as lascivious as wolfishly possible. Please stop me.
Comment: If you are specifically looking to describe a dog perhaps ['doggishly'](https://www.merriam-webster.com/dictionary/doggish) can work. His dog ran 'as fast as doggishly possible'.
Comment: "He'd chuck as much wood as a woodchuck could."
Comment: As fast as doggedly possible.
Answer: I would use "physically" here, rather than attempting to create new words from each individual.
To me, 'the dog ran as fast as physically possible' sounds better than 'the dog ran as fast as doggedly possible' given the fact that 'doggedly' is already used as an adjective/synonym to tenacious. This can also be applied to other animals that do not lend themselves well to such structure, eg "The rabbit reached as high as physically possible" sounds much nicer than "The rabbit reached as high as rabbitly possible."
EDIT
You could also use "naturally" in this sense, eg, "the rabbit reached as high as naturally possible," meaning as high as it could do without artificial assistance.
Comment: Then just say *as fast as possible*.
Answer: One option might be to use adjectives associated with certain types of animals, e.g. canine, feline, etc. You could append -ly to make them adverbs like humanly, like, "It ran as fast as caninely possible." While these aren't quite as natural as humanly in everyday speech, I think you'd be unlikely to confuse people with such terms.
Comment: Would those make valid words? It might be fun to be responsible for a neologism, if there's no existing better option.
Answer: In the context of the question we probably deal with real animals (a running dog), then it is possible to consider: "as fast as nature made it possible".


Insensitivity of MEG to inhomogeneous conductivity

Question: Why MEG is not sensitive to inhomogeneous conductivity profile of different brain compartments (scalp,skull and brain) but EEG is sensitive to that?
Answer: MEG measures magnetic fields and EEG measures electrical potentials.
One property of magnetic fields is that organic matter (scalp, skull, and brain) does not block them in any significant way.
Electrical potentials measured on the scalp, on the other hand, are definitely affected by the matter between the source of the signal and the location they are measured. This is because the scalp, skull, and brain provide significant resistance to the flow of electrons.


What is the difference between fractional shares and unit linked investing?

Question: As the title says, I am confused about the difference. From my understanding both allow you to own a share of a company without owning a full share.
Comment: I don't know what country you're in, but in the US, there are some brokerages that allow you to buy fractional shares (Motif Investing and Folio Investing are two examples). Behind the scenes, they are buying full shares, and pooling money from multiple customers who want fractional interests in those shares).
Answer:
unit linked investing

As an individual to mitigate risk one would invest in Mutual Fund, ETF or similar constructs [unit linked Life Insurance, etc].
The concept being you invest in small amounts and the fund then invests into actual shares. In theory you own a fraction of all such shares.

fractional shares

This is slightly similar concept, but works on single share. If one does not believe in any of the Mutual Funds and their underlying stocks but want to invest directly into shares; the funds required would be large. So if you want to buy something, you pool your money with other like minded individuals and buy a fraction of the share.


Can I visit India for 2 months with an extension on I-94 and an expired L1B visa?

Question: My L1B visa expired February 2014, and I got an extension on I-94 till January 2016. I have a new petition valid till January 2016. My son was born here in the US August 2013. My wife also has the same expiration dates. Can my son and wife travel to India for 2 months and come back? Will there be any problem in stamping in India?
Answer: Your extension on I-94 allows you to remain in the USA. I believe when you leave the USA, your I-94 will get an exit stamp. When you leave the USA your I-94 is over, unless it is a short-trip (up to 30 days) to Mexico, Canada or adjacent islands, in that case they will re-validate your existing I-94.
Leaving the USA for any other country, like India will result in your I-94 showing an exit stamp. When you return they will have to issue you a new one, however you will need to have a valid visa to get one.
Without a valid visa they probably won't issue you a new I-94, and on the Indian side you probably won't be allowed to board the flight.
Your son will be allowed to re-enter as he should be a USA citizen by birth (you may need documentation to prove that). Your wife will not be allowed back in without the appropriate visa.
Comment: Actually, without a valid visa, I'm not sure the airline in India will even board him for the trip back to the US.


What's the earliest source for the Third Temple?

Question: I know Yechezkel writes about a Temple which is generally considered to be the Third. Is this explicitly identified as a Third Temple anywhere there? Otherwise, what's the earliest source that explicitly says there will be a Third Temple?
Comment: It needs to be unambiguously referring to the third one or unambiguously claiming there will be a third one. In particular I want to know whether there are any such sources before the second was destroyed, but I made the question more general to ask for the first source.

So if there's a source after the second was destroyed saying another will be built, it would count.
Comment: Does it have to specify how many Temples there were prior? Or is reference to a Temple which isn't destroyed sufficient?
Comment: Very interesting question!   I know the Rambam talks about renewal of korbanot, but that's waaay later than what you are probably looking for.
Answer: There is no 3rd Temple in a religious sense. It's a rebuilding of the second. The holiness of the second Temple is "sanctified for its time, and sanctified through to the future to come" -- ie all eternity. Just as we don't consider Herod's rebuilding and enhancement of the Second Temple to be a 3rd Temple, technically the messianic one will be a rebuilding of a Temple whose holiness is already there. Not a new Temple. It's only the nearly 2 millennial gap between them that make the language of "Third Temple" (בית שלישי) useful. But despite common usage, even in very notable primary rabbinic sources, it's not really meaningful on halachic or aggadic levels.
As to actually answer the question you were obviously trying to ask...
When neither the Great Assembly when they first built the second Temple, the Maccabbees and Herod when they rebuilt it conformed to Ezekiel's description, the notion that it must be rebuilt again became compelling.
So, aside from people deducing as much during the 2nd Temple, it was enshrined shortly after in the siddur. The prayer on Divine Service, said in the Temple (Tamid 5:1, quoted in Berakhos 11a), was adapted for the Amidah as the blessing that begins "Retzeih". In it, and many equally ancient quotes from the siddur, we ask G-d to restore the Temple and its worship. The request to return the service to the Sanctuary of Your House might date back to the Second Temple era, a request to restore those elements of First Temple worship that were impossible in the second. But more likely the words were inserted at the time it was adapted for post-temple use.
In addition, and codified in text only a couple of centuries even later, the laws of kings require that restoring the kingship would obligate him to make sure a Temple exists. Since there is none now, unless one comes down from heaven (Midrash Tanchuma, Pekudei 11), the messianic king would be obligated to build one (Jerusalem Talmud Megillah 1:11, Pesachim 9:1).
Comment: Can we source Retzeih to before the Second Temple's destruction?
Comment: @ike: Does this change to that paragraph clarify or confuse?
Comment: It sounds like you're tracing it to after the Second's destruction. Is that correct?
Comment: Tracing what? The insertion of a request in "Retzeih" to restore the service? Yes, I think that's more likely. The belief there would be a third Temple? No, that I date to each attempt to build the second using a design that isn't based on interpreting of the prophet's description.

But I think that from a halachic perspective, we should remember it's really a refurbishing of the Second Temple after a very long down time. Which is why the Temple Mount currently has the Temple's holiness. More in kind to what Herod or the Maccabees did than what Ezra did.


Help to remove handles from leaky bathroom faucet

Question: I have a leaky bathroom faucet. There are no screws on the sides of the handle or escutcheon. I cannot figure out how to pry off the top without causing some damage. Maybe someone can look at the picture I've attached and make a suggestion on how best I can fix this thing?
Answer: Usually with that type you pry off the cap on the top and find a screw underneath which holds the handle to the stem of the valve. Probably you pry off the entire cap but it could be only the white center.
Answer: yep the screw is under the cap. If you look closely around the edge of the cap, there should be a slot for a small flat head screwdriver to fit into to pry it off.
Comment: Hello, and welcome to Home Improvement. The OP already guessed that the screw was under that cap; any suggestions for how to remove it without causing damage? (Please edit your new information into your answer.)


How do you show that $e^{-1/x^2}$ is differentiable at $0$?

Question: Define the real valued function $f(x)$ by $f(x) = e^{-1/x^2}$ if $x \ne 0$ and $0$ if $x = 0$.

How do you show that $e^{-1/x^2}$ is differentiable at $0$?
How do you show that this function is infinitely differentiable?
Answer: It should be clear that for $x \neq 0 $, $f$ is infinitely differentiable and that $f^{(k)}(x)$ is in the linear span of terms of the form $f(x) \frac{1}{x^m}$ for various $m$. This follows from induction and the chain and product rules for differentiation.
Note that for $x \neq 0$, we have $f(x) = \frac{1}{e^{\frac{1}{x^2}}} \le \frac{1}{\frac{1}{n!}(\frac{1}{x^{2}})^n} = n! x^{2n}$ for all $n$.
In particular, for $n=1$, we have $f(x) \le 2 x^2$ for all $x$. It follows that $\lim_{x \to 0} \frac{f(x)-f(0)}{x-0} = 0$, and so $f$ is differentiable at $x=0$, and $f'(0) = 0$.
Now suppose that we have shown that $f^{(k)}(0)=0$. As mentioned above, for $x \neq 0$ we have $f^{(k)}(x)= f(x) \sum_{i=0}^N c_i \frac{1}{x^i}$. Choosing $n$ suitably large above shows that $f^{(k)}(x) \le C x^m$ where $m \ge 2$, from which we get $\lim_{x \to 0} \frac{f^{(k)}(x)-f^{(k)}(0)}{x-0} = 0$, and so $f^{(k)}$ is differentiable at $x=0$ with $f^{(k+1)}(0) = 0$.
It follows that $f$ is infinitely differentiable at $x=0$, and $f^{(k)}(0) = 0$ for all $k$.
Comment: Use the Taylor series for the exponential.
Comment: Why the downvote?
Comment: How do you show the first inequality?
Answer: The essential thing to know here is that $e^x$ swamps out any polynomial as $x \rightarrow \infty.$  The usual way to see this is by expanding $e^x$ in a Taylor's series and observing that this series always has more terms than any polynomial, so it will always go to $\infty$ faster.  Alternatively and equivalently, you can use L'Hospital's rule many times and come to the same conclusion.
$x \rightarrow \infty$ is the same as 1/x $\rightarrow$ 0.  Either way, the exponential part of the expression will control what happens.
No matter how many times you differentiate $e^{x^2} $ you will get $e^{x^2}/x^k $ (times various constant terms which have nothing to do with the limit) for some k > 1.  Taking the limit as $x \rightarrow 0$ the $1/x^k$ factor will head toward $\infty$, but the $e^{1/x^2}$ will head for zero faster. In every case the exponential term will govern what happens and that term is going to zero, both from the right and left.  So you can conclude that all derivatives exist and are 0 at x = 0.
This function is a cumbersome construct whose purpose is to show that a function can have infinitely many derivatives at a point and not be "analytic" there.  Analytic can be defined for real functions as meaning that the Taylor's series converges to the original function.  I mention this in case you are wondering why anyone asked you this question.
Answer: You want to compute $$\lim_{h \to 0}\frac{\exp(-1/h^2)}{h}$$ Show this is equivalent to computing
$$
\lim_{k \to +\infty}k{\exp(-k^2)}
\qquad \text{and} \qquad
\lim_{k \to -\infty}k{\exp(-k^2)}.
$$
and show they are equal. Then things get easy.
For your second question, see this.
Answer: Hint:
You can prove by induction that there exists polynomials $P_n, Q_n$ such that
$$\frac{d^n}{d x^n}  e^{-1/x^2} = \frac{P_n(x)}{Q_n(x)} e^{-\frac{1}{x^2}}$$
You can also show by the change of variables $t=\frac{1}{x}$ that, for each $m$ you have
$$\lim_{x \to 0} \frac{e^{-\frac{1}{x^2}}}{x^m}=0$$
From here you can deduce both claims.


Differences between System.Linq.Dynamic, EntitySQL and Expression Trees

Question: I am currently working on a large project that uses Entity Framework extensively. Part of the functionality we have implemented is dynamic querying (Filter/Sort) of the various data models based on user-supplied filters.
To achieve this I ended up using System.Linq.Dynamic which allows me, through various means, to create string-based filters like like "SomeProperty.StartsWith(@P0)" and so on, and then pass these strings (and attendant parameters) to the Dynamic Linq extension methods for IQueryable<T> (Where, etc) so that they get executed against the database and everyone is happy.

I didn't know any other way to do this at the time except for a vague
  notion of Expression Trees and to be honest, I just could not get
  my head around them - I spent several weeks poring over a decompilation of a component that used expressions to implement dynamic querying and I balked :)
Plus it felt like I was reinventing the wheel when the functionality I needed effectively was already written by far cleverer people than myself, in the System.Linq.Dynamic extensions.

Now the current code all works quite well as a generalised solution for filtering, sorting, etc, on any of my entities, and I'm happy enough with it however as I became more and more familiar with E.F. I started to come across things like

ObjectQuery
EntityClient
EntitySQL
Expression Trees

And I started to wonder, given that System.Linq.Dynamic is nearly 6 years old, and hasn't really had anything done with it in that time, am I missing out on anything? or, have I missed some fundamental point?

Should I bite the bullet and move my codebase over to use EntitySQL? (I assume this is like the spiritual successor to System.Linq.Dynamic, or am I wrong?)
Or should I go back and learn how to use Expression Trees because they are the way of the future/all the cool kids do it, etc? I'm not a fan of change for changes sake, and I like code that works, but I am worried that at some point in the future string-based dynamic linq becomes a dead-end and I'm stuck using it.

If anyone can help to clarify the differences between System.Linq.Dynamic and EntitySQL, or can identify any good reason for moving to Expression Trees I'd really appreciate it.
Answer: We are using Dynamic Linq extensively in our project...
Its clean and it works well, but its very complicated if you would want to peep into or change anything its code.
One of the problems what I found using a combination of Dynamic Linq and EF 6 is
EF 6 uses query caching to perform faster retrieval of data and the way where query that is built in Dynamic Linq does not use this feature of EF 6. So we have to change the where to use query caching.
This is just a small example to say Dynamic Linq is not meant for newer EF versions.
Dynamic Linq is a wonderful solution if you want to work with un-typed collection like IQuerable, but its very difficult to maintain.
I am hoping you would work in a typed environment(IQueryable). Otherwise essentially you would need to modify Dynamic Linq to really take advantage of EF 6.
Comment: Thanks for the insights. We are looking to upgrade to EF6 so I guess I'll need to have a closer look at Entity SQL.
Comment: How did you go about getting EF6 to cache queries generated using compiled expression trees?


What is the meaning of "Rumgejuxe"?

Question: Does anyone know what the meaning of "Rumgejuxe" is?
I assume it is related to "juxen" or something, but I'm not sure.
I googled it, but it does not have many matches.
Comment: Closely related: https://german.stackexchange.com/questions/5684/pejorative-gerund
Answer: There are a few nouns of the form Ge- + -e derived from verbs:

das Gebrüll(e), Gehabe, Gelaber(e), Geklopfe, Gelache, Gerede, Getue, Gezanke, ...

The meaning is pejorative, i.e. the activity denoted by the noun is perceived as being unpleasant.
So Gejuxe is a noun derived from juxen (to joke). The prefix (he)rum literally means around; here, it denotes an activity without a goal (as it can in English as well). Which leads us to Rumgejuxe ~ the act of joking around.
Comment: "Durch ihr Herumgebrülle hat Sonja wahrscheinlich die Hyänen vertrieben." "Sein Herumgejuxe hat einen Headhunter für die Comedybühne aufmerksam gemacht." Ich würde sagen die Bedeutung des Wortes ist neutral - erst der Kontext macht eine Unterscheidung in abwertenden Gebrauch oder nicht möglich.
Comment: Ich sehe die Grundbedeutung durchaus als abwertend. Daß negative Dinge auch positive Effekte haben können, steht außer Frage.
Comment: Weil es beim Hörer eine andere Erwartung wecken würde. Deshalb würde derjenige, dem es gefällt, vielleicht von einem *Heidenspaß* sprechen. -- Um die Einstufung als "abwertend" plausibel zu machen, schaue man sich die Kollokationen von *Gerede* an: *leeres, sinnloses, dummes,* ... . Dagegen *Gespräch*: *klärendes, konstruktives, gutes, nettes, ...*
Comment: Abgesehen von Abstrakta wie "das Negative" oder "der Schaden" usw. glaube ich nicht, dass es objektiv negative Dinge überhaupt gibt. Wenn 2 Personen Zeuge eines Rumgejuxes werden, einer findet es schlecht, einer gut, wieso sollten unterschiedliche Begriffe dafür verwenden? Was spricht für den, der es gut findet, dagegen, das auch Rumgejuxe zu nennen?
Comment: A) Ein Heidenspaß hat man, Herumgejuxe ist dagegen ein Verhalten. Das sind nicht Synonyme nur mit unterschiedlicher Bewertung. B) Gespräch und Gerede auch nicht. Ein Gerede kann man alleine ausführen. Dass es meist abwertend benutzt wird macht nicht jedes Herumgerede abwertend. Zwei Marketingleute etwa können sich über erfolgversprechende Kundeninteraktion unterhalten. "Dem Kunden schmeicheln, Ersparnis herausstellen, etwas Herumgerede - schon hatte ich den Vertrag in der Tasche".
Answer: In addition to David Vogt's answer: Some of the verb + Ge constructs in popular speech combine with Rum, some not:
Verb + Ge + Rum

Rumgelaber
Rumgejuxe (obviously)
Rumgeschreie (Hört endlich mit dem Rumgeschreie auf!)
Rumgesumme
Rumgebrumme
Rumgezanke
Rumgelache
Rumgehüpfe
Rumgehopse
Rumgetolle
Rumgerenne
Rumgedudel (typically with a musical instrument, or a radio)
Rumgeklimper (on a piano)
Rumgefuhrwerke (rare, rather: das Rumfuhrwerken)
Rumgeklopfe (here start craft trades or home improvement activities)
Rumgehämmere
Rumgesäge
Rumgeschleife
Rumgefeile
Rumgeschnipple (with scissors, also: Rumgeschnippel)
Rumgesauge (with a vacuum cleaner; could also refer to a suckling)
Rumgetue
Rumgekaspere (difficulties to find the correct spelling show us that all these words are never used in writing)
Rumgeknutsche
Rumgehure
Rumgebumse

Contrary to that I am not aware of a popular Rum prefix for

Gehabe

If one searches for reasons of semantical logic, I would suggest: all the Rumge- words refer to activities of a person that create noise or motion suitable to annoy others. Gehabe, in contrast, refers rather to a posture or attitude not actually emitting noise or motion.
The Rumge- double prefix is very productive. You can use it on any verb fitting the above description. So, you could try to use

Rumgeföhne

if your girlfriend does not stop blow-drying her hair for hours. But I have never met that word in actual use.
Note that all these words are pretty much restricted to oral, casual communication. You would not find them in written communication (unless of course in literature depicting oral speech as in drama). Using them correctly in oral communication, however, would be an indicator of a high level of command of German. (Not least because they would be hard to find in a dictionary.)
Comment: Rumgehabe obviously refers to a person who owns ridiculous amounts of rum. "Sein Rumgehabe ist nicht mehr erträglich, er sollte lieber Whiskey kaufen."
Comment: I should have mentioned the pun was intended.
Comment: @infinitezero  In my understanding ***Rumgehabe*** is rather a word for the behaviour of a person who has been having too much rum, as *Gehabe* is posture or attitude. (Compare to ***Bierlaune***, the joyful mood of a person who has had a certain amount of beer.) The circumstance of owning a lot of rum (and being bold about it) would rather be ***Rumhaberei***.
Comment: @infinitezero: no, it never comes from a noun (Rum) - "Rumgehabe" is a coincidence purely because of its (almost illegal) shortcut - remember that "Herumgehabe" is the full version. This meaning of "Rumgehabe" practically only appears in (word) jokes. One would rather say "sein Gehabe über Rum" or "Rum-Gehabe".
Comment: Do these words all have the same gender? If so, what is it. Plus can they ever be plural?
Comment: @Wilson: Yes, all substantives are neuter. None of these has a valid plural since it is an abstract process description (as *das Hören*), the official term is [Singularetantum](https://de.wikipedia.org/wiki/Singularetantum).
Comment: "Rum-" stands for "herum-", which can be translated as "around, about", I think. dict.cc has an example here: https://www.dict.cc/german-english/ich+kaspere+herum.html  (herumkaspern = rumkaspern = to clown about)
Comment: @infinitezero  Continuing this line of thought, ***Rumgejuxe*** can of course also be understood as a joking attitude under influence of rum, as ***Schnapslaune*** refers to people being loud and either funny or agressive after consumption of brandy.
Comment: @AmigoJack : He was probably just rumgejuxing.
Answer: A "Jux" is a joke or a prank. "Rumgejuxe" is the act of joking around, not necessarily in a nice way. If some people want to work seriously and others just fool around, the serious guys might say: stop that "Rumgejuxe". "Rumgejuxe" is rather colloquial.
Answer: The closer your word is to the proper, correct, precise, formal word for the action, the more respect you have for the way it's being done.
If the word you use is close to, but not exactly "correct", you're just being casual (and as somebody pointed out, you're probably speaking, not writing).  If you get further away, you're being disrespectful or downright insulting.
Example: your Rumgejuxe.  Juxen is a correct, formal word for joking, and rum is short for herum (around), so juxen means you're joking around, casually, like with your buddies.  Juxerei is another version.  These are not insulting, merely casual.
Now, if you use a word that could be applicable, is more generic and further from the proper word, e.g., getue or rumgetue (doing around), it starts to get into the realm of serious disrespect. You're saying what's being done might not even be  recognizable as joking, it's so bad.  If you were to use geschrei (screaming), this is a flatly incorrect description of the action, and thus very far from correct, and definitely insulting.
In English this is sort of like saying you saw someone's trumpet performance vs show vs messing around vs screeching.
Comment: I would inject that this differs from region to region. While getting away from the proper formal form of a word has a meaning, this is not always disrespectful or insulting. In Vienna, for example, using dialect forms of a term often denotes that it's meant less serious and also less insulting. So for example calling someone an "Idiot" is really insulting, since it is High German and thus meant seriously. Calling someone a "Wappler" for example, which is a Viennese word with a similar meaning, is often meant more jokingly. You would use that when messing around, for example.
Comment: So in one region Rumgejuxe might be used by someone who can't stand the noise and bother that someone creates. In Vienna you wouldn't use the word "Jux", but Rumgekaspern would mean something very similar. But because it uses multiple casual markers it would be something a parent might use towards their child, that they love, when it's joking around.

What is the meaning of "Rumgejuxe"?


Cut strand of hair longevity?

Question: Quick and useless question : what can be the longevity of a cut strand of hair, assuming we kept it in (good) normal conditions ? Any idea ?
Comment: "assuming we kept it in (good) normal conditions" - your definition of normal matters.I recently read that some of the dead from Herculaneum had intact hair. That was more than 2000 years ago. And that's far from the oldest hair specimens.
Comment: Fossilised hair can last over 200,000 years. http://www.telegraph.co.uk/news/earth/environment/archaeology/5299352/200000-year-old-human-hair-found-in-dung.html
Answer: In order to keep the hair from decomposing, my first assumption is you'd need it in an environment that inhibits decomposers, e.g. dry. We can see in the mummification process that hair may be preserved for hundreds of years. Hair is also composed largely of keratin, however, and in my own search of the literature: (1) we need microbial (bacteria, fungi) keratinases to decompose the keratin in hair [source], and (2) this process is slow. There's a really old article here, from the abstract:

Keratin, prepared from horn meal, was added to moist field and garden soil and allowed to decompose in the laboratory. The keratin was found to undergo a decomposition resulting in a slow, but steady accumulation of ammonia and nitrate. 35–40 per cent, of its nitrogen was transformed into nitrate after 120 days.

More recent numbers to shed light on a rate of degradation for keratin are either obscure, or untested. This is more so for hair specifically as I couldn't find much more.

Cut strand of hair longevity?


Does an urn's probability distribution change as you draw from it without replacement on average?

Question: Suppose I have an urn containing N different colours of balls and each different colour can appear a different number of times (if there are 10 red balls there need not also be 10 blue balls). If we know the exact contents of the urn before drawing we can form a discrete probability distribution which tells us the probability of drawing each colour of ball. What I am wondering is how the distribution changes after drawing k balls without replacement from the urn on average. I understand that as we draw from the urn we can update the distribution with the knowledge of what has been taken out, but what I want to know is what we would expect the shape of the distribution to be after we have removed k balls. Does the distribution change on average or does it remain the same? If it does not remain the same can we write down some formula for the what we expect the new distribution to look like on average after making k draws?
Comment: i might be wrong - but this feels like that one knows the prior distribution, but has no informatoin about the likelihood (besides that k balls are removed). in that case - i would assume that the posterior is equal to the prior. To be fair - there is likelihood information that the number of balls has decreased, and that (for one ball removed) the distribution is hence e.g. bimodal between 50% possiblity of 9 red and 10 black and 50% possilbiity of 10 red and 9 black. i mgiht be wrong here though
Comment: My intuition is that it is like the latter case which you described. I cannot find anyone speaking about this sort of process though.
Answer:
"Direct calculation": Let there be $n$ balls of $m$ colours in the urn. Let us focus on the probability of drawing one particular colour, say white, on the second draw. Let the number of white balls be $n_w$. Let $X_i$ be the colour of the ball obtained at the $i$-th draw.
\begin{eqnarray}
P(X_2=W)&=&P(X_2=W|X_1=W)P(X_1=W)+P(X_2=W|X_1=\overline{W})P(X_1=\overline{W})\\
&=&\frac{n_w-1}{n-1}\frac{n_w}{n}+\frac{n_w}{n-1}\frac{n-n_w}{n}\\
&=&\frac{n_w(n-n_w+n_w-1)}{n(n-1)}\\
&=&\frac{n_w}{n}\\
&=&P(X_1=W)
\end{eqnarray}
Of course this same argument applies to any colour on the second draw. We can apply the same kind of argument recursively when considering later draws.
[One could of course perform an even more direct calculation. Consider the first $k$ draws as consisting of $i$ white balls and $k-i$ non-white balls (with probability given by the hypergeometric distribution), and perform the corresponding calculation to the simple one above but for the draw at step $k+1$; one gets a similar simplification and cancellation, but it's not especially enlightening to carry out.]
A shorter argument: consider labelling the balls randomly with the numbers $1,2,...,n$, and then drawing them out in labelled order. The question now becomes "Is the probability that a given label, $k$, is placed on a white ball the same as the probability the label $1$ gets placed on a white ball?"
Now we see the answer must be "yes" by symmetry of the labels. Similarly, by symmetry of the ball-colours, it doesn't matter that we said "white", so the argument that label $k$ and label $1$ have the same probability applies to any colour. Hence the distribution at the $k$-th draw is the same as for the first draw, as long as we have no additional information from the earlier draws (i.e. as long as the earlier drawn balls are not seen).
Comment: Closely related to your 2nd way, is another short argument: imagine the set of all possible sequences in which the balls can be removed (e.g. blue first, then white, then white, ... might be one such sequence). If for each sequence in this set we swap the $1^{st}$ and $k^{th}$ elements, we simply permute the set. So for every sequence with a white (or whatever) ball in position $k$, there is exactly one corresponding sequence with a white ball in position $1$. Hence the probability of a white ball in position $k$ or position $1$ must be the same. I think this is essentially Neil's argument.
Comment: @Silverfish  Yes, looking at it, my second argument is essentially the same sort of argument as Neil's permutation argument.
Comment: Thanks for the explanation. It was exactly what I needed to see!
Answer: The only reason it is not perfectly obvious that the distribution remains unchanged (provided at least one ball remains) is that there is too much information.  Let's strip out the distracting material.
Ignore, for a moment, the color of each ball.  Focus on one ball.  Assume $k$ balls are about to be randomly removed (and not observed), and then a $k+1$st ball will be drawn and observed. It makes no difference what order the selection occurs in, so you might as well observe the very first ball drawn (and then remove another $k$ balls if you insist).  The distribution obviously has not changed, because it will not be affected by removing the other $k$ balls.

This argument--although perfectly valid--could make some people feel uneasy.  The following analysis might be accepted as more rigorous, because it does not ask us to ignore the selection order.
Keep focusing on your ball.  It will have some probability $p_k$ of being selected as the $k+1$st ball.  Although $p_k$ is easy to compute, we don't need to know its value: all that matters is that it must be the same value for each ball (because all balls are equivalent) and that it be nonzero. But if it were zero, no ball would have any probability of being selected: so as long as at least one ball remains, $p_{k}\ne 0$.
Pay attention to the colors again. By definition, the chance that a particular color $C$ will be chosen (after $k$ balls are randomly removed) is the sum of the chances of all the original $C$-colored balls divided by the sum of chances of all original balls.  When there originally are $k_C$ balls of color $C$ and $n$ balls total, that value is
$${\Pr}_k(C) = \frac{k_c p_k}{n p_k} = \frac{k_c}{n}.$$
When $k\lt n$ it does not depend on $k$, QED.
Comment: Thank you for the comment. It helped me understand the underlying processes more!
Answer: Let the distribution of drawing a single ball — after having already drawn $k$ balls without replacement — have categorical distribution $E(D_k)$ given the distribution over such categorical distributions $D_k$.
I guess you are asking whether $E(D_k)$ is constant.
I think it is.  Suppose that you eventually draw all of the balls.  All permutations of the balls are equally likely.  The probability of drawing initially is $E(D_0)$.  You could rearrange your choices to an equally likely permutation whereby your first chosen ball was chosen last, and your second chosen was chosen first.  That ball has expectation $E(D_1)$, which must be equal to $E(D_0)$ due to symmetry.   By induction the $E(D_i)$ are all equal.
Comment: You mean that I am asking whether $E(D_k)$ is constant for every k, right?
Comment: @mjnichol right
Answer: The "expected distribution" do not change.  One could use a martingale argument! I Will add such to the answer later (I am travelling now).
The distribution, conditional on the earlier draws (for the later draws) do change only when you actually observes the draws.  If you draw the ball from the urn with a tightly closed hand, and then throws it away without observing its color (I have used such theater effectively as class demonstration),  the distribution do not change.  This fact has an explication: Probability is about information,  Probability is an information concept.
So probabilities do change only when you get new information (conditional probabilities, that is).  Drawing the ball and throwing it away without observing it does not give you any new information, so nothing  new to condition upon. So when you condition on the actual information set, that has not changed, so the conditional distribution cannot change.
<code> EDIT
</code>
I will not now give much more details to this answer, only add one reference:  Hosam M. Mahmoud:"Pólya Urn Models" (Chapman & Hall), which treats urn models like the one in this question, and also much more generalized urn schemes, also by using martingale methods for obtaining limit results.  But the martingale methods are not needed for the question in this post.
Comment: @Neil I think kjetil is referring to the distribution *conditional on the observed draws*.
Comment: The distribution (for the later draws) *does not* change even when you actually observe the draws. Why should observing anything change anything?
Comment: @Silverfish: Ah I see.  You're right, my apologies.
Comment: I Will edit to make clearer when at home in some two weeks. For now vacation in Venezia...


How to print a regular file to pdf from command line

Question: In gedit, printing a file gives an option of printing to file where the file can be saved as a pdf. How can I do the same thing from the command line?
Comment: Cross-site link: same question on Unix.SE [text processing - How to convert TXT to PDF? - Unix & Linux Stack Exchange](https://unix.stackexchange.com/questions/17406/how-to-convert-txt-to-pdf)
Answer: Here's a solution that doesn't involve OpenOffice:

sudo apt-get install enscript
enscript my_text_file.txt -o - | ps2pdf - output.pdf

There are more options to enscript, e.g. -B to omit the page header. See man enscript for all of the options.
Comment: Good alternative Stefano especially for anyone not using open/libreoffice as unoconv is dependent on either of these being installed.
Comment: Thanks! It works for most texts, however enscript only works with old encoding, it doesn't work with UTF-8 for instance so you can't convert a text if it includes the euro symbol (€) for instance...
Comment: +1 for the nice answer, the one I was about to give, I just decided to give one I think will add something to what is already here.
Comment: Isn't there any inbuilt bash programme or command to do this?
Answer: without installing any of the above mentioned  software, one can simply do the following with already installed cupsfilter:
cupsfilter foo.txt > foo.pdf

(for options etc. please refer to cupsfilter man pages :-) )
Comment: The only answer here that handled my UTF8 text files without problems :) plus easier to do with virtually no dependencies
Comment: Unfortunately this solution generates unsearchable PDF [How to copy/paste text from PDF generated by cups-pdf? - Unix & Linux Stack Exchange](https://unix.stackexchange.com/questions/335848/how-to-copy-paste-text-from-pdf-generated-by-cups-pdf)
Answer: THE SIMPLE ENSCRIPT WAY

sudo apt-get install cups-pdf enscript

Then run enscript on your file with the -P switch and the printer description PDF in this case.

enscript -B -PPDF test.txt

A printer with description  PDF was created when you installed cups-pdf, when you use enscript with that printer your document will be sent to the PDF printer and will be printed to file, created as .pdf in your /home/PDF directory, the command above will print the text file test.txt as a pdf in the PDF directory.
USING UNOCONV

sudo apt-get install unoconv

You can use unoconv in standalone mode, this means that in absence of an OpenOffice listener, it will start its own:
In the directory where your file is located run:

unoconv -f pdf test.txt

this will create a nice looking pdf of test.txt. in the current directory
Comment: `enscript foo.txt -o bar.pdf` works quite well; thanks!
Comment: Actually, this generates postscript instead of pdf. Need another ps2pdf pass.
Answer: There is a command line program that can convert between all of the formats supported open/libre office called unoconv  so if you need to batch convert with a script it will come in handy.
sudo apt-get install unoconv

Unoconv Homepage
Answer: Pandoc is a must have swiss knife tool when it comes to conversion between various markup languages. To get you started first install pandoc converter:
sudo apt-get install pandoc

General and most frequently used syntax for pandoc is:
pandoc -f <from format> -t <to format> <source file>

Please note that you need texlive-latex-base package to be installed first, before you can convert to PDF format. Otherwise you will get a following error:
pandoc: pdflatex not found. pdflatex is needed for pdf output.

To install it:
sudo apt-get install texlive-latex-base

Now you can easily convert any file to pdf.
pandoc -t txt -t pdf source.txt

replace txt with your text format(odt - html - ....)
Comment: Compared to the other answers, pandoc plus texlive produces bad output (not respecting newlines), and is overkill and confusing to boot.  Lots more packages are needed, pulling in texlive, texlive-fonts-recommended, ruby, etc.  E.g. I get `pandoc: Unknown writer: pdf` until I install texlive-latex-base.   This is on trusty.  See https://github.com/jgm/pandoc/issues/1155  Then I got an error about a missing font, then one about url.sty, etc.
Comment: Did you mean for the first `-t` in `pandoc -t txt -t pdf source.txt` to be `-f`?
Answer: paps is a better alternative than enscript
paps file.txt | ps2pdf - output.pdf

Comment: Welcome to Ask Ubuntu hwc! While your post does answer the question, it's always better to include more information. For example, why is `paps` a better alternative? And if `paps` is not installed by default, what is the command to install it? You can always [edit] your answer by clicking on `edit` right underneath the body of the answer. Thanks!
Answer: I had some issues with german Umlaute (ÄÖÜ) with the above mentioned solutions. Or, in the case of paps, the resulting PDF does not have a text layer.
The best solution for me was to use wkthmltopdf. It seems to be not documented, but you can easily convert text files into PDF files by using this syntax:
wktmltopdf <textfile> <pdffile>

wkhtmltopdf can handle UTF-8 files (unlike enscript). All problematic chars like ÄÖÜß etc. will be displayed correctly.
Comment: This has been fixed in the latest version of paps, which is able to output selectable pdf. See: https://github.com/dov/paps .
Answer: As posted above, enscript is a popular way to convert text to postscript, which can then be further converted to PDF.
A similar tool, which has been around for a long time, is a2ps.  It has a large number of options, including putting multiple pages on a physical page.  Install ap2s with
sudo apt-get install a2ps.
AFAIK, enscript and a2ps do the same job, but their interface is different and YMMV with each of them.
Comment: An example of using a2ps would help.  The --delegate option seems to be needed for pdf, but the man page doesn't really help there.
Answer: You can use    a2x

a2x - convert Asciidoc text file to PDF, XHTML, HTML Help, ODF,
  manpage
          or plain text

To install a2x:
sudo apt-get install asciidoc

for example:
 a2x -f pdf testfile.txt

Answer: You can use u2ps too.
This generates both ps and pdf.
This accepts UTF-8 text, and supports syntax highlighting through Pango markups.
Answer: Here is a modern alternative that does not require installing unoconv:
libreoffice --headless --convert-to pdf myfile.txt

This will create a file in the current directory just like unoconv. Since LibreOffice is installed by default on Ubuntu, this solution has the benefit of not requiring additional software.


Webhook activates only on certain action

Question: My scenario is i have a list of folders representing companies,each time i have to create a new folder(company) a webhook event is triggered and it call an azure function that assign permission to that  folder and create some sub folders. I noticed that if i do upload a file in the subfolders the webhook is triggered!!!
Is there a way that it trigger the webhook only on creating a new company? or an alternative way to achieve the same result apart from using webhook
Answer: As of now SharePoint Webhooks respond to any action within a list. Also only Asynchronous events are being taken care of. We really dont have the flexibility to isolate the events.
The only option would be to write your logic within the Azure function where you will get the item ID using (change as ChangeItem).ItemId} . Now create a list item object using this ID.
Once you have the list item object, check if it is a file or folder using the CSOM code. This was you can run your logic only if the item that caused the event is a folder
<code> if (listItem.FileSystemObjectType == FileSystemObjectType.Folder)
{
    Console.WriteLine("Folder item ");
}
else
{
    Console.WriteLine("File item ");
}
</code>
Comment: possible workaround but not a good business solution,each time this check is performed the azure function is working and it cost money for the client,If not webhook is there another alternative ?
Comment: i dont think this solution will work in my case,you are just verifying if the changeitem is a folder!! but in my case a new company is a folder but am creating subfolders also,won't they count as folder??? my initial logic should affect only the company folder not the subfolders in it. @Priyaranjan KS
Comment: With webhooks you are left without any other options. The only options then would be to use Remote Event Receiver using Provide Hosted Add-Ins
Comment: what if i replaced my inner folders by document set,do the above code still works? @Priyaranjan KS


Go and Apache2 license compatibility

Question: Is it fine to use a Go-licenced 3rd party library (https://github.com/google/re2j) within an Apache2-licensed code?
Answer: The license of the re2j project you linked to is a 3-clause BSD license. This is perfectly compatible with Apache 2.
This 3-clause BSD license requires that you do not remove the license notice from the source code, that you include the license notice in your documentation, and that you don't use Google's brand to promote your software (duh!). None of these requirements conflict with Apache 2, which essentially requires the same things.
The Apache 2 license uses a NOTICE file mechanism for acknowledgements and upstream licenses.
If you include the re2j software into your project, you should probably add the re2j license to your project's NOTICE file. If you merely declare re2j as a dependency that's not necessary for your source code, but note that these requirements still trigger if you distribute a binary (like a jar file) that includes the re2j software.

Go and Apache2 license compatibility


Assumed level of safety on the Home Experiment Tag?

Question: In our comments and Answers Should we assume a proper level of safety precautions being taken?
Answer: I've been trying to keep in mind my own mixture competence and insane lack of regard for personal safety around my fourteenth birthday.
More specifically I look for work that can be done safely in a home environment and I try to specify what safety gear you should wear and/or have on hand.
Answer: It's not our job to explain safety precautions to people, if that's what you're wondering. The answers here, when they describe experiments, are meant to be read as "this is basically how X might be done" rather than "here is how to do X" - in other words, we're just conveying knowledge about what is involved in running a particular experiment, not providing instructions on how to actually do it. If someone wants to carry out an experiment described in an answer, it's their responsibility to do whatever additional research is necessary to find or develop a proper set of instructions, including safety precautions.
As sort of a corollary to that, if someone asks whether some particular procedure or effect is safe, or about how to do something safely, it's off topic for the site. We can answer questions about the effects of a certain amount of a physical phenomenon, though. For example, "What are the effects of running current through a human body?" is a fine question, but "How much current can safely run through a human body?" is not. If someone asks in a comment whether something is safe or not, it's best to either not answer, or just say you can't address that.
Comment: I've down voted this because the idea that asking for safety considerations of an experimental procedure is off topic is a massive disservice to experimentalist users. It is also bizarre to anyone who works in a lab. Physics courses contain safety information on included lab experiments. To an experimental physicist safety considerations are an *integral* part of daily life in the lab.
Comment: Furthermore, asking about safety considerations of e.g. lasers, cryogenic liquids, or certain compounds are questions *only a physicist can answer*. As such, these questions have the same relevance as math questions that only physicists can answer, which we obviously allow.


If all intermolecular forces are electrostatic in nature, why don't large non polar molecule dissolve in water?

Question: If I have a large non-polar substance A that forms strong dipole-induced dipole force (DIDF) with water, with strength comparable to that of H-bonds between water molecules, will A dissolve in water?
Comment: If you have a cockroach with strong hands, comparable to those of a man, then yes, your hypothetical cockroach could probably beat a man.
Comment: The point is that non-polar molecules form only much weaker bond with water because they can form only dipole -induced dipole interactions (which are way weaker than hydrogen bonds in water).
Comment: Solubility is strongly dependent on entropic concerns.
Comment: @Zhe - solubility at low solute concentrations is strongly dependent on entropy. High solute concentrations (such as in solid alloys) have significant enthalpy contributions.
Comment: @JonCuster If we're concerned about something being soluble at all, then we're clearly working in the low concentration regime.
Answer: Dipoles can be induced, but they are not permanent. You're basically asking why a spring doesn't like to stay compressed when you push on it—it's because that's not its most stable position. The electron density around  hydrogen in a $\ce{C-H}$ bond is much higher than the hydrogen in a polar $\ce{O-H}$ bond, so electrostatic repulsions overwhelm any attractions that may be induced. See the diagram below$[1]$:

$[1]$ Bond polarity diagram - Iverson Group UT Austin
Answer: Don't confuse the strength of interactions with the underlying nature of the interactions
Yes, intermolecular forces are all caused by electromagnetic fields (your title says "electrostatic" but this is slightly wrong as some forces are also caused by interactions you might call magnetic. But the underlying forcefield is the same either way.)
But just because the forces are electrostatic doesn't mean they will be strong. Some interactions involve oppositely charged ions interacting  and they are usually strong (this is easily visible in bulk electrostatic experiments like charged balloons sticking to a wall). Next in strength are the interactions where molecules are not charged but have strong dipoles because of (to simplify a little) some degree of charge separation internal to the molecule (these are caused because some elements hog their electrons much more strongly than others). Some of these are so strong and unusual we give them special names: hydrogen bonding (basically a strong and directional dipolar effect with some extra pixie dust because hydrogen is such a light nucleus). Essentially every molecule that is not symmetric will have some dipole, though many will be very weak (asymmetric hydrocarbons have very small dipoles but chlorocarbons have relatively strong ones). But non-polar things (even atoms of noble gases) eventually stick together enough to liquefy. The dominant forces here are van Der Waals forces. These are still electromagnetic attraction based on dipoles but the dipoles are caused by quantum fluctuations in the electron density in the atoms or molecule's bonds. These forces are fairly weak compared to ionic or dipolar interactions.
It is also worth remembering that everything has van der Waals forces but in polar molecules they are just a lot weaker than the dipolar interactions.
So, although the underlying cause of attraction is always something to do with electromagnetic forces, sometimes those forces are very weak. Crudely, they may be too weak to make something soluble.
But solubility is a little more complicated than that. It isn't just about the nature of the force it is also about the detailed mechanism of solubility. For something to dissolve in water you don't just need a strong attraction between the molecule and water, the interaction has to be strong enough to compensate for the inherent attraction of water molecules to each other (which is pretty strong). van der Waals interactions are usually too weak by themselves (even when induced by a strongly dipolar water molecule) to create a strong enough attraction. And, when you take the loss of water-water hydrogen bonds into account if you stick a large non-polar thing into the middle of a bunch of water molecules, the whole equation looks even less favourable for solvation.
If you had something where the induced attraction was as strong as water-water hydrogen bonds, it might well be soluble in water. But that hypothetical compound is extremely unlikely to exist because of the relative strengths of the induced versus the inherent dipolar interactions (which is even worse when you take account of the large number of hydrogen bonds you have to break to fit a large molecule into solution).
Answer: Answer edited; In a polar solvent non-polar molecule will have dipole - induced dipole energy as well as some induced-dipole, induced-dipole energy which is smaller. The enthalpy of dissolving a non-dipole molecule in water, such as cyclohexane, is small, some types of molecules have have a small negative or some a small positive value, so the fact that these type of molecules do not dissolve to any great extent is due to entropic effects because $\Delta G = \Delta H-T\Delta S$ depends on entropy change when $\Delta H $ is small.
Mixing is always entropically favourable ($\Delta S$ positive) so something else must be causing the entropy to become negative. This is due to the fact that water has  hydrogen bonds and these are used to bridge any 'intruder' molecule. This limits their geometry and hence make entropy negative and so $-T\Delta S$ positive and free energy positive.

If all intermolecular forces are electrostatic in nature, why don’t large non polar molecule dissolve in water?