How to connect earth(grounding) that has copper wire attached?

Question: This is my first time doing a light fixture. In the ceiling, the wires are black, white and green wire with a copper wire attached to the green wire.
 In my light fixture, there is a brown wire, blue wire and a yellow wire with green stripe ( which is attached to the fixture housing). I went through online to figure out I have to connect (black with brown wire, white with blue wire) I am just confused how to connect the copper wire(from the ceiling), green wire(from the ceiling) and the yellow wire (from fixture). Do I connect the yellow wire to the copper wire or to the green wire? Hope I explained it clearly.
Comment: Where are you?  It sounds like you have an IEC color coded fixture and North American building wiring, which isn't *wrong* per se, but does raise some questions...
Answer: The bare copper wire is a "pigtail" that exists to make your connection to the light fixture easier. I'm guessing that you have a metal junction box (which requires its own ground connection).
Simply nut your fixture's ground wire to it. The key is that all grounds are connected to the panel. It's usually not critical what the actual path is as long as the connections are sound.
Answer: United States

Ground: Green, yellow/green stripe, or bare wire  (same)
Neutral: White or gray
Hot: any other color

Europe

Ground: Green, yellow/green stripe, or bare wire (same)
Neutral: Blue preferably light blue
Hot: Brown is first choice, then varies somewhat

All grounds should be joined together.  You are grounding to the supply, and the metal junction box, and the lamp proper, and the lamp shroud if any.


In Sicario, why did Kate pull a gun on Alejandro?

Question: Kate apparently went in the "wrong tunnel" and sees Alejandro holding a corrupt cop at gun point.  Since they had just shot their way through the drug mule tunnel, what surprised her to cause her to pull a gun on Alejandro?  It was obviously a big plot point as subsequently Matt (Josh brolin) explains the whole CIA plot to her.
Comment: Because she understands that he is a "double agent".
Answer: TLDR:
She doesn't know what Alejandro is, but she knows they're in Mexico, they've no jurisdiction whatsoever and she's just seen Alejandro hold a criminal at gunpoint, force him into a car and demand he drive him. She doesn't know what his motives are, but doesn't trust him and so doesn't lower her gun.
Answer:
Kate is trying very hard to do things by the book. She works for the FBI and in the film becomes increasingly concerned that the team is working outside of their jurisdiction. However, the very reason she and Reggie are part of the team is to give protection to the CIA unit. From the script:

REGGIE: What the fuck is he dressed for?
MATT: Relax. You guys will hang
  back when we get there, k?
REGGIE: Then why are we going?
MACY: Because CIA
  can't operate within US borders without a domestic agency attached.
  Right?
  At last. She gets it. He smiles.
MATT: Hey. All the drugs we find,
  you guys get to confiscate. Gonna be a big day.
He walks off.
MACY: That's why we're here. That's the only reason.

As they proceed through the tunnel, Reggie gets spooked, but Macy needs to continue to understand why they're there:

REGGIE: Fuck are we doing in here? Let's go back.
Machine gun fire
  erupts. The fight has begun.
REGGIE (CONT'D): We're in fucking
  Mexico!!
MACY: THEN GO BACK.

Macy finally reaches the end of the tunnel she's not supposed to go down:

MACY (O.S.): WHAT ARE YOU DOING??
Alejandro turns and sees Macy, her
  rifle trained on him.
ALEJANDRO: Put that down.
MACY: STEP AWAY. I mean it. Move away from him.
He looks at her.
The automatic fire from different
  tunnel shafts rushes in and out like blasts of hot air.
ALEJANDRO: We are
  in Mexico now. You have no jurisdiction.
MACY We can't be
  here
--Alejandro raises his pistol and fires six rounds into Macy's
  chest.

After that, as you correctly explain, the whole CIA plot is explained to her.
I've highlighted the relevant section in the passage above. Macy is completely out of her depth. At the start of the film, we see her operating in a house with bodies hidden behind every wall. She's supposed to be a tough, strong, powerful agent. But even with all those qualities, she's still completely out of her depth in this team.
She's told to stay away from this particular tunnel, that she doesn't want to know what's at the end. She has to know. So much has been kept back from her. And as she goes, she sees Alejandro hold Silvio at gunpoint, force him into a car and tell him to drive him.
Macy is terrified by this. As the highlighted line above shows, she's highly aware they're not in Mexico and have zero legal jurisdiction. She doesn't know if Alejandro is CIA or enemy. She doesn't know anything - except that this man has crossed into Mexico, is holding a criminal at gunpoint and demanding he drives him.
Macy doesn't deal with these things in her usual job. She makes arrests. She demands he steps away, with her gun trained on him, just like an agent is supposed to do in these situations. However, she is distracted by gunfire and shot herself.
Answer: Because in Kate's opinion EVERYTHING had done was illegal and she had no proof that THAT PARTICULAR Mexican cop was corrupt. However, as she saw it, her side HAD broken U.S.laws as she understood them at the time. That's why Graver choose Kate instead of Reggie since he was "a lawyer".


Dataset of historical economic forecasts

Question: Where could I get a dataset of economic forecasts made over years? For instance, the history of predictions for GDP, current accounts, and other key national variables by the World Bank and IMF? Or similar information from governments?
Answer: The World Bank provides an excellent overview and summary, as well as detailed current and historical data.
Additionally:

You can get information from individual government open data portals (scroll to bottom), but it's inconsistently formatted and may not be available from all governments.
Oxford Economics provides country economic forecasts.  There's summary information here, and an archive of free open data here. (Note that there is a fee to get access to all their data, although you can get a free trial.)
The International Monetary Fund has a summary of GDP and detailed data.
Answer: You may be interested in
Domenico Giannone, Jérôme Henry, Magdalena Lalik and Michele Modugno 2010), An area-wide real-time database for the euro area. ECB Working Paper Series No 1145 / January 2010 available at http://www.ecb.europa.eu/pub/pdf/scpwps/ecbwp1145.pdf.
There are some details of the data base on the EABCN web site and data can be downloaded by non EABCN members at https://www.ecb.europa.eu/stats/shared/download/stats/sdw/docu/databases/rtdb/rtdb_csv.html
Answer: Old question but I will throw in a secondary source:
http://apps.resourcegovernance.org/forecast-tracker/
On this site you can find, filter and download (+ visualize) aggregated data from multiple years of IMF World Economic Outlook forecasts (most recent here). The data is available on the IMF site, but not aggregated across years (so you have to download forecasts from 2015 in one file, 2016 in another, etc.).
The WEO covers nearly all countries, dozens of economic indicators as well as dozens of commodity price forecasts, all available on the site. Data is updated semi-annually, with the release of new data by the IMF.
[disclosure: I created this app]


Solr - character substitution

Question: I have Solr with indexed database. In my database all data is in Latvian. The problem is, I need to be able to search word Riga as if it is word Rīga. Of course, i can define synonym  - Rīga = Riga, but can i just define, that letter ī is letter i? I read something about solr.ISOLatin1AccentFilterFactory, but as far as i understood, this is not for UTF-8 encoding, right? Advices?
Answer: Used PatternReplaceFilterFactory with index and query. Seems to be working right.
Answer: ISOLatin1AccentFilterFactory is exactly what you are looking for... as long as the accent EXISTS in the latin-1 character set (lower 7 bits of UTF-8 are identical to latin-1).  The ī that you mentioned doesn't appear to exist in ISO-8859-1 so ISOLatin1AccentFilterFactory won't work in this SPECIFIC case.   I would still recommend that you use ISOLatin1AccentFilterFactory in addition to any exceptions that you take care of using PatternReplaceFilterFactory as there probably are some Latvian characters that it will help (assuming, I don't have experience with Latvian)
FYI, I did actually try the against my Solr setup with ISOLatin1AccentFilterFactory and it didn't help this case.
Answer: Look at ICUTokenizerFactory which provides Unicode character normalization.  Extremely useful and very easy.
http://lucene.apache.org/solr/api/org/apache/solr/analysis/ICUTokenizerFactory.html
http://site.icu-project.org/

Solr - character substitution


How many planes are there?

Question: I'm new to D&D and I thought I read about teleporting to different planes. How many planes are there and what are they like?
Comment: Related: [What are the full names of all the outer planes?](https://rpg.stackexchange.com/q/33354/33569) (3.5e), [What was behind the creation of the gods/planes?](https://rpg.stackexchange.com/q/30493/33569) (3.5e), [What are Planes in Pathfinder?](https://rpg.stackexchange.com/q/37157/33569) (Pathfinder), [What are the planes of D&D 4e? Where did they come from, and how are they connected?](https://rpg.stackexchange.com/q/41174/33569) (4e), [World Axis Cosmology](https://rpg.stackexchange.com/q/59848/33569) (4e)
Comment: ...And more: [Which Outer Planes are ruled over by a single god or entity in the Forgotten Realms?](https://rpg.stackexchange.com/q/121404/33569) (5e), [Are the Material Planes comprising the various campaign settings surrounded by a shared set of outer planes?](https://rpg.stackexchange.com/q/130507/33569) (5e), [Are the positive and negative planes inner or outer planes in the Great Wheel cosmology model?](https://rpg.stackexchange.com/q/141893/33569) (5e)
Comment: The previous comments helping to refine the question have been [moved to chat](https://chat.stackexchange.com/rooms/95408/discussion-on-question-by-john-stoneman-how-many-planes-are-there).
Answer: The number and arrangement of planes varies considerably between different D&D campaign settings, different editions of the game rules, and even individual players' games.
However, the most common cosmology is known as The Great Wheel, and is the default in the current D&D 5th edition (Player's Handbook p.300), in the World of Greyhawk and Planescape campaign settings, and in many previous editions of D&D including 3rd edition and earlier.
I recommend reading D&D 5e's Player's Handbook p.300, Appendix C, The Planes of Existence; Dungeon Master's Guide p.43, Chapter 2, Creating a Multiverse; and Wikipedia's entry on Plane (Dungeons & Dragons), which will give the information you need. However, the overview is as follows:

The world in which the player characters inhabit is the Material Plane.

Depending on your worldview, you can travel to alternate parallel material planes, or alternate worlds within the same material plane, by various magical means. You can canonically travel between the worlds of different campaign settings, or even to our Earth.
There are also the Feywild, an alternate Material realm where faeries live, and the Shadowfell, a dark and twisted version of our world.

There are the Inner Planes, which are made of pure energy:

The four Elemental planes of Fire, Air, Earth and Water
The Positive and Negative energy planes are counted Inner Planes, and comprise the source of all life energy as well as the anti-life energy which animates undead

The Outer Planes, the realms where the gods reside:

There are sixteen major Outer Planes, including the infinitely-layered Abyss where demons live, the 9-layered Nine Hells, and the realms where the good deities live
There are potentially other, less well known Outer Planes.

The Transitive Planes, which allow you to travel between planes:

The Astral Plane, allowing travel between the planes, traditionally including the travel of souls from the Material Plane to the Outer Planes where their gods reside
The Ethereal Plane, a foggy realm traditionally allowing travel between the Material and Elemental Planes

Other planes, including:

Demiplanes, small planes pocket which can be created by powerful wizards
The Far Realm, a truly alien landscape beyond the edge of time and space

One generally travels between planes using portals or plane-shifting magic.
However, there are potentially unlimited numbers of planes other than this, and even explaining the existing planes in detail would require multiple entire books. In practice, the exact detail of the planes is up to the individual DM and based on their interpretation of the lore available to them.

How many planes are there?


How to get Vietnam mainland visa in Phu Quoc?

Question: I got visa exemption when arrived to Phu Quoc. Now I want to fly to Hanoi and they want mainland visa in Phu Quoc because it is domestic flight. I have visa invitation letter for Hanoi but it's not valid. It is possible to get mainland visa from travel agent in Phu Quoc airport in 30min but it costs a lot, procedure looks very strange (although it worked for me) and seems to be the only way. Is there any other way to get mainland visa when I already have Phu Quoc visa exemption?
Answer: There is only 1 option for you in this case: you need to contact with either the Immigration Officer or the travel agent (as mentioned) to get them process the mainland Vietnam visa in Phu Quoc for you.
You can save money by getting Visa on arrival for Vietnam (with cheaper price) before departure to Vietnam, but once you enter Vietnam, you cannot use that method (source.)
Comment: Immigration office could sell directly with official pricing so this would look as more reliable process. Travel agent can say any price because there are no other options in that situation.
Comment: If time is not an issue, you can go to Cambodia and then fly to Vietnam mainland.


How can a military combat pilot indicate surrender?

Question: If a military pilot is captured by an enemy, how can he indicate that he has run out of ammunition to engage in combat or is not in a position to retaliate? Does he use lights, radio, and/or flares?
Comment: The question is stil unclear to me:
If a military pilot has been captured by an enemy, he/she's being held prisoner in a way or another.
On the other way, if the crew is still in the aircraft, the only scenario i can think of is a pretty large aircraft (transport/tanker, SIGINT/ELINT, AEW, ecc) being intercepted by one or more fighter aircraft like in event of an airspace violation.
In an event like that, I think standard signaling (like wings waving, nav lights flashing ecc.) can occur.
Otherwise, if I'm in a maneuverable plane, why not trying to go defensive and evade incoming threats?
Comment: It needs two for a successful surrender. You would need an [extraordinarily principled opponent](https://en.wikipedia.org/wiki/Charlie_Brown_and_Franz_Stigler_incident) - most enemy pilots would relish the chance of an extra kill with no risk.
Comment: just asked in Politics SE: [Can a jet fighter "wave a white flag"?](https://politics.stackexchange.com/q/71622/16047)
Answer: There is no universally accepted means of surrendering an aircraft. According to Humanitarian Policy and Conflict Research at Harvard University,

Aircrews of a military aircraft wishing to surrender ought to do everything feasible to express clearly their intention to do so. In particular, they ought to communicate their intention on a common radio channel such as a distress frequency.

They can do other things like rocking the wings, jettisoning the weapons, flashing navigational lights etc. However, none of these are universally accepted or even have a clear meaning in the heat of combat. So the best course of action will be to bail out.
If a pilot is captured by an enemy, there would be no need to surrender.
Comment: Lowering landing gear is also often considered a sign of surrender. A combination of dramatically slowing, turning navigation lights on, dropping landing gear and rocking the wings will likely signal clearly enough that you intend to surrender... if the enemy can see you. In the age of guided missiles, however, they probably won't. The best surrender is to be out of the aircraft and clearly no longer a threat.
Comment: And will likely get you shot!
Comment: I just had an idea: what about turning on the transponder? Provided the aircraft is equipped with one, of course. Surely, broadcasting "here I am, shoot me if you want!" is going to get the enemy pilot's attention, and hopefully in the right way.
Answer: If the pilot engaged in combat, and simply ran out of ammunition, surrendering isn't something that has to be accepted by the opposing party. The rule is, you need to surrender on first sight of the enemy. Once you engage in combat all bets are off and you can be destroyed even if you release the canopy and throw up your hands (not recommended!) See, people get a peculiar sentiment when you shoot at them. They appreciate that you missed, but they don't take kindly that you offered surrender after you go winchester on the missiles and bullets.
Also, while you are surrendering. Assuming you didn't engage in combat, consider learning the other side's language and make sure you surrender in a top of the line aircraft. For example, Viktor Belenko defected in a Mig-25 in 1976 by flying it to Japan. This was a very valuable aircraft which he traded for a carton of American cigarettes and a million dollars. (ok just kidding, but he did get a nice trust fund set up for him when President Ford accepted his asylum plea.)
Answer:
Generally theres no surrender bail out, In the pacific theater during the Second World War there was no aircraft surrenders. In fact even if the pilot chose to bail out of his aircraft (American Pilots) they would be strafed while in their parachute, and even if they had made it to the water. ( Japan did not sign the Genova accord) For this reason many American pilots returned the  favor and would go so far continue shooting at the already critically damaged Japanese fighter.
Comment: Hi and welcome to the site. Do you have any sources to back up those claims you make?
Comment: One reason to keep shooting at Japanese aircraft that were clearly damaged was that the Japanese had a tendency to suicide by ramming something as long as they had any control left, not because the Americans were cold blooded killers out for revenge.
Answer: In WW2, USAAF bombers would some times signify an intent of the aircrew to bail out of a shot up bomber, by dropping the landing gear. The hope was that the attacking fighters would stop shooting, and not kill more of a crew that was just trying to get out and would be captured upon reaching the ground.
This was not official policy on either side, but it was occasionally done, and occasionally respected.


Why do politicians create more advertising badmouthing their opponents, rather than promoting themselves?

Question: I live in Iowa and have been inundated with a lot of political advertising everywhere (TV, mail, internet) as the 2020 US election approaches. It seems to me that most of the political advertising from all side mostly focus on characterizing opposing candidates as evil rather than pointing out positive attributes of the candidate the ad is promoting. Why do politicians and their campaigns do this? Is it more effective? If so, why is it more effective?
Comment: Comments deleted. Please don't use comments to answer the question. Write a real answer instead which adheres to our quality standards.
Comment: I suggest it's partly for the same reason the media appears to concentrate on bad news… A house burning down concentrates into a few hours of excitement and risk roughly the same energy that was used to build it over tedious months
Answer: The United States system promotes a sharply divided two-party system. That's called Duverger's Law and like any such "laws" it is no ironclad automatism, merely a clearly observable trend.
So anything which is bad for the others is automatically good for the own side. The disadvantage of being seen with smear tactics and of wasting the advertising budget without promoting yourself if compensated by the smut that sticks (see the answer by Beginner Biker). If there were three or four parties and two of them got into a smear battle, the votes might well go to one of the others.

In my opinion, which is not directly part of the answer, the US had a great Constitution some 250 years ago, but it was so great that they got out of the habit of updating it when new developments came along, like the railway or the telegraph. They merely added patches on top of patches. There is a technique in fault analysis to ask "why" five times.
Why are they slinging mud? Because it sticks.
Why does it stick? Because there are just two candidates.
Why are there just two candidates? Because of the majority vote.
Why majority vote? Because individuals are running for separate offices, not political parties.
Why pretend that there are no parties if they clearly do exist?
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/115118/discussion-on-answer-by-o-m-why-do-politicians-create-more-advertising-badmouth).
Answer: Most people, most of the time, think that things are pretty good, or at least tolerable, the way they are.  As the US Declaration of Independence puts it "...all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed."
The logical consequence of this is that the majority of voters don't often want great change, which is a large part of the reason incumbents tend to be elected.  So as a candidate, you have several choices:

Portray yourself as just like your opponent, not wanting major changes but better looking, more likeable, charismatic, &c.  Not really a path to victory, unless the opponent gets involved in some personal scandal.

Portray yourself as the candidate of change.  But since unless things are really bad, most people don't actually want change.  You probably don't even get your party's nomination (e.g. Bernie Sanders); if you do, you wind up with a landslide loss, like George McGovern in the 1972 US Presidential election: https://en.wikipedia.org/wiki/1972_United_States_presidential_election

Portray the opponent as being really evil, and wanting to destroy (or having destroyed, if they're the incumbent) the system that people have gotten used to.  Instead of being an agent of change (which most people don't want), you portray yourself as preventing|undoing the nasty changes the opponent wants|was responsible for.

Number 3 is the tactic that is most likely to succeed, especially when (as in the current US elections) there really is some substance on which to hang the "really evil" accusations.
Comment: *incumbents tend to be elected* — that is certainly not the case in most countries.  The US is quite unique in that respect.  In much of Europe, governments are voted out of power at every election, because the government is at the major disadvantage that they have to defend actual policies, whereas the opposition can run on criticism and promises.  This is even more true in parliamentary systems where coalition governments are common. Your answer makes it sound like Biden presents himself as conservative, which I don't think is accurate.
Comment: @gerrit: Perhaps I don't know enough about European politics, but AFAIK a government can be voted out by flipping a handful of seats, much as the US House & Senate can change party majorities even though most of their members are regularly re-elected.  It's perhaps less obvious in the US, since there are three different things (including the President) that can be held by one or the other party, elected at different times, so it's unlikely for then whole government to switch parties in an election.  (And Biden is certainly more conservative than Sanders.)
Comment: @gerrit: The notion of "incumbents" is typically tied to single-seat districts, typical of the Westminster FPTP system, or the two-seat states in the US Senate. Mainland Europe often has nation-wide PR with party lists. In such a context, an elected representative has no direct relation with a particular subgroup of voters.
Comment: @gerrit even the European coalition goverments often get an "incumbent boost". Well, at least the German ones; perhaps that's an outlier.
Comment: @gerrit: In the US, you have a defeated or term-limited President, who almost always retires from political life, whereas in the parlimentary system the Prime Minister of the defeated party just goes back to being an ordinary MP.  (If they were not defeated in their run for their individual seat, of course.)  Although they may resign from party leadership, they don't have to.  And of course the party in power may win the election, so the PM stays in power.
Comment: @James_pic: Sure, but that is custom, not something required by law.  Just as no US President prior to FDR broke the 2-term limit custom set by George Washington.
Comment: @MSalters True.  I was rather thinking of U.S. Presidents, which are often re-elected, vs. governments in European parliamentary systems, which are often voted out.  Although presidential systems differ from parliamentary systems, in both cases you have a government which faces voters defending its actions of the past 4-5 years.
Comment: I think you do see strategy #2 used successfully from time to time, usually when the incumbent is unpopular but either not on the ballot (e.g. Obama vs. McCain) or too small-c-conservative for overt vilification to make logical sense (e.g. Clinton vs. Bush).
Comment: @jamesqf That differs per country and is not generally true in European parliamentary systems.  In the UK defeated prime ministers often go back to being an MP, but in The Netherlands, defeated prime ministers almost always retire from politics.  I'm not sure about other countries.
Comment: Even in the UK, whilst defeated prime ministers do automatically revert to being ordinary MPs, most step down from their seats soon after defeat. Theresa May is an exception to this, but Cameron, Brown, Blair and Major all left parliament soon after, if I recall.
Answer: Political ads cost money and have to be kept short.
It's pretty easy to pick one of your opponent's policy mistakes, flawed outcome or something they misspoke and weaponize that into a short, clear negative argument that can either strengthen the commitment of your voters or induce your opponent's voters to doubt and stay at home.
It's more difficult to pick to one of your positions and make a quick positive statement about why it's a good idea.  Short statement like "I will bring more jobs" will not convince undecided electors - they've heard that before.  Longer explanations risk losing viewers and will cost more money.  Regarding past outcomes, an incumbent may very well have some policy successes to point to, but a challenger doesn't have that.  Finally, even short policy statements may turn off some of your sympathizers:  "I will stop all immigration" will be a vote winner for xenophobes, but less so to some employers in low wage industries.
The negative soundbite about what an opponent said is uniquely well suited to the medium as it can strip away all the context around what they said.
Note that some countries have rules against negative advertising, whether in a political context or not, that preclude political attack ads.
Answer: Because  they work.
Source: Being a political strategist/local politician in a Western democracy.  Have had a lot of fun with highly effective negative campaigning.
it works.
But it works most effectively when you associate the positive elements of your campaign with the negative elements of what the opposition is (supposedly or actually doing).  E.g. if you're campaigning on the opposing party squandering the municipal authority's money through reckless spending, you emphasise that you are committed to bringing fiscal discipline to the authority.  Amateurs will just bash the opposition; pros will bash the opposition and promote themselves at the same time.
Comment: This is the right answer.  As I understand it (I've been a political junkie for decades), campaigns have tried just about everything, and they return to negative campaigns for the simple reason that they give you the best bang for the buck.  It works best when you can hijack your opponent's "narrative" by consistently painting them in the same negative color.  Ask any American about Hillary Clinton and the answers you will get will be about Benghazi, Emails and "Lock her up". Republicans in Congress painted her with Benghazi.  Wikileaks and Trump handled the emails and "lock her up"
Comment: Consider John Kerry's campaign for president.  Kerry came out of the Viet Nam war with three purple hearts, a bronze star and a silver star on his uniform.  He was running against George Bush who had spent the war in the Texas Air National Guard, so Kerry's military service was expected to be a big part of the campaign.  Knowing that, the Bush campaign preemptively began the Swift Boat campaign (https://en.wikipedia.org/wiki/John_Kerry#%22Swiftboating%22_controversy), painting his service as a liability.  Somehow, the Republicans were able to use his military record against him
Comment: It's particularly effective when campaigning for low-level, local elections that no-one really cares about.  You can work very hard to get people to care about your earnest attempt to improve parking facilities, or you can make people angry about some relatively unimportant issue like wasteful spending by the local authority and make it central to your campaign.

My limits (in terms of personal morality) were: never attack your opponent's character as individual people.  That's wrong.  And never tell lies or fabricate things. All of my attacks were absolutely legit.
Comment: In my case, the local authority was actually recklessly spending money, to an insane degree (e.g., spending more than the equivalent of twenty thousand US dollars on a set of folding chairs which were completely unnecessary, making multi-million dollar investments based on woefully inept financial planning), and jacking up taxes for local rate-payers. So this was absolutely a legitimate point to campaign on
Answer: While you did not put a country tag, I assume that you are asking about the US.
As an alternative perspective: I have never seen that in France and it would be at least weird here.
Sure, during direct interactions they will tell the other candidate(s) that they are the worst that happened on earth since the Permian Extinction but that would never go in an advertisement, posters, ...
Comment: @quarague It's also cultural.  The Dutch Socialist Party had a controversial (and quality-wise atrocious) very negative political ad in the EU 2019 elections, they were vilified for "American style campaigning", and lost all their seats in the subsequent elections.
Comment: @d-b this is somehow the case in France. See https://www.seban-associes.avocat.fr/wp-content/uploads/2015/08/pub_cdm271_50questions.pdf (in French), points 31, then 22. The content of the ad is left to the candidate, but there is regulation about defamation, insults, etc., with an emphasis on the campaign. How that would end in court is another story, but in any case such ads would be very negative for the candidate that would have used them.
Comment: That is because a) France does not have a 2-party system like the US does (see o.m. answer to why this matters) and b) there are much stricter laws about what can be said in a (political) advert in France than in the US. The vast majority of political advertising you see in the US would not be legal in France or most other Western European countries.
Comment: @WoJ Defamation can also get you into trouble in the U.S. It's not a crime (i.e. you can't be fined or go to jail for it,) but it definitely is a tort (i.e. someone can successfully sue you for it.) In particular, making a defamatory statement that you know at the time of making the statement to be false can get you successfully sued. However, politicians (and, for that matter, the media) frequently try to skirt this by making statements that might have a technically true interpretation, but which are intentionally horribly misleading.
Comment: @quarague Illegal? Let me doubt that. I have never heard of campaign ads in Europe being accused of crossing the line of legality, which should be common if there was such a line (that doesn't mean that they would be convicted in court but it should be a common accusation to throw at competitors).
Comment: @reirab: defamation laws are pretty different in France compared to the common-law countries https://journals.sagepub.com/doi/pdf/10.1177/0306422014537174
Answer: There are two reasons for this. The first as has been mentioned in other answers it is an attempt to get voters to change their vote from the opponent to the candidate who is running the attack ad.
The second and I think is to get the voter whose support you won't be able to win to not vote at all. I have heard the results of this both in 2016 and in 2020. In 2016 I was hearing that someone couldn't vote for either Trump or Hillary and the reasons for not voting for Hillary were based on the attack ads. I am hearing similar accounts this year for Biden which makes it seem the idea of costing your opponent is as good as getting them for yourself.
Comment: [Politico had an article "An Unsettling New Theory: There Is No Swing Voter" back in February](https://www.politico.com/news/magazine/2020/02/06/rachel-bitecofer-profile-election-forecasting-new-theory-108944) talking about your second point
Answer: Avoiding danger and "bad" outcomes is more evolutionarily important to any species than is achieving optimal outcomes. For that reason, people are just naturally more primed to respond to warnings and alerts of danger. Our eyesight, our hearing, our senses of taste, touch, and even smell all interrupt our activities and respond much more immediately to danger than to good things. So negative advertising against one's opponent is simply more effective (at an instinctual, subconscious level) at turning out voters in one's own favor.
Answer: Because they work. Voters like to take a rather holier than thou attitude to politics, but the reality is that politicians only reflect what voters want.
Negative ads aren't necessarily false. If the result of voting for party A is X, and X is regarded as undesirable, then why shouldn't  party B construct an advertising message around this? Do you not want to be informed of the undesirable consequences if you vote for party A?
I do think, however, that a negative adverts that aren't telling the true are morally repugnant.
Comment: I am not sure that is what voters want but it is what they respond to.
Comment: "but the reality is that politicians only reflect what voters want." On this point, I'd strongly disagree. If you want proof, look at the favorability ratings of both candidates in the 2016 Presidential election. Maybe they reflect what _some_ voters wanted, but certainly not a majority. In the 2016 primaries, in many of the early states that Trump won, he had numbers in the 20s or 30s, but there were so many other candidates that he ended up winning the primary anyway. Had Kasich dropped out before Super Tuesday, we'd probably have President Rubio or maybe Cruz.
Answer: Sorry to add yet another answer but...
The answer is simply that politics makes for strange bedfellows.
It's harder to campaign on your platform, because people who are nominally "on your side" are not going to support every aspect of your platform. It's much safer to lambast your opponent for the things that made the people on your side be on your side in the first place.
By way of example, how much do Hillary and Bernie supporters really agree on beside how much Trump sucks? I mean sure there are some things that anyone on the Left are going to agree on, but the fault lines are there and it makes way more sense as a political strategy to paper over them by rallying around hating Trump than having them register on the Richter scale the way they did during the last election.
Same thing plays out on the Right where you have an increasingly uneasy coalition of military-industrial complex neocons, religious fundamentalist tradcons, tea partiers, and (sometimes) libertarians. Oh, and that one guy who doesn't really belong in any of those groups...
The things you focus on are going to be the things everyone on your side agrees on, and those will be almost definitionally be the things that differentiate Right from Left in the broadest possible way, and it's easier to rally around those values by deriding your opponents for not having them (or for giving them less importance than you consider their due). Liberals think minorities are people too is page 12 news. "Liberals accuse Trump of being openly white-supremacist" is front page news. Conservatives want the government to spend less is page 12 news. "Barack Obama is a Socialist!" was front page news.
You can also take a controversial view that only a subset of people on the other side hold (e.g. communism on the Left, homophobia on the Right) and try to tar entire opposing side with that brush more easily that you can get your own side to rally around your (internally controversial) platform.
In our FPTP system it's the best way we've found so far to maintain party unity among diverse groups.
Comment: This answer could be improved by specifying which election you meant registered on the Richter scale.
Answer: Let's separate out the ideal of politics from the reality of it. On the ideal level, we like to think that we are choosing the person who will lead the nation in the best manner (meaning the most intelligent and wise). On an intellectual level that is precisely what we want from an elected official: sound leadership, reasoned use of authority, moral coherence, and civic responsibility. We want someone who will take charge and do the right thing in response to the curve-balls that life throws at us.
In reality, though, we don't make assessments of candidates in the kind of reasoned, deliberate way we like to imagine of ourselves. We assess candidates in terms of their attitudes (in the particular way that George Herbert Mead used the term): a pre-linguistic, quasi-biological blend of posture, movement, vocal intonation, etc, that projects strength and security on a primitive level, much the way that dogs sense power in another dog's stance, growl, or the focus of its eyes, and submit without a fight. Politics on this level comes down to projecting an archetypal image that people instinctively respond to. We respond more viscerally to someone who projects a strong character than to someone who presents sound ideas, because we intuitively believe that character is what brings ideas into fruition. And yes, there is some validity in that intuition: knowing the right course of action and bringing it to pass are two different skill sets, and the latter is arguably more useful for a leader in society.
In the era before mass media took hold (pre-1930s) this visceral, attitudinal evaluation only applied to the candidate selection process, in groups that were small enough to meet the candidate personally. General elections were far more focused on policies and issues, because most people only knew the candidates in terms of their public statements about policies and issues. But as mass media became widespread, it became politicized, and the focus shifted began to shift away from the platform the candidate was standing on to the character of the candidate. Running for office became performance art: a carefully constructed theatrical effort to portray the candidate as having the correct attitude to lead. But one of the consequences of this increased visibility and shift towards character assessment — and of the performative aspect in particular — was an increase in efforts at character assassination: of hecklers trying to disrupt a high-minded, noble performance with jeers and insults. The campaign experience became progressively more like a literal dog-fight, with candidates focused more on trying to make other candidates submit, than on trying to connect with and attract citizens/voters.
As we've progressed into the modern social media era, most political campaigns have recognized that expressing actual policies and platforms — that is, anything more substantial than offering vague moral postures — merely creates an angle for opponents to attack a candidate's character. Any attempt to expand on policy during a campaign will immediately be dissected by innumerable opponents looking for opportunities to attack the candidate's intelligence, credibility, authenticity, honesty, or other 'character' qualities that can be used (dog-fight style) to force the candidate into a submissive posture. Trumpism is perhaps the epitome of this. From Trump's pugnacious, bullying efforts to overwhelm Biden at the first debate, to the WWE style of Trump's general campaign (all the puffed-up, blustering, trash-talking elements of WWE short of bashing people with folding chairs), to the offensive and idiotic strains of QAnon conspiracy, to the overtly in-your-face attitude of Trumpists nationwide, Trumpism has made this election entirely about character assassination, so that there is literally no place for calm, coherent discussions of policy to take place. But Trumpism isn't the cause of this issue; Trumpism is merely the natural, (il)logical extension of the increased visibility of candidates and the consequent increased pressure of this visceral, attitudinal aspect of politics.
There are solutions to this problem — which I add because I don't want this to seem quite as jaded and hopeless as it might sound — but this is not the place to get into them. Perhaps on some other question...
Answer: At the expense of being tautological, because the point of political campaigns is getting more votes than the opposition.
Convincing people to expand the effort is usually very difficult because of the fact that any one person's vote doesn't swing the election.
Convincing the voters to vote requires providing enough impetus for them to galvanize them to vote.
There are 3 types of ads:

Negative ads (come slay the dragon by voting)
Positive ads (come hug the teddy bear by voting)
Policy ads (come participate in governing by voting)

Negative ads tap into the fight-or-flight response.  They create the perception of the opposing candidate as a monster who is attacking and can be fought with as little effort as casting a vote.

Positive ads create a perception of a politician being a lovable member of the family who can be "hugged" by simply voting.  These do appeal to the people who are unhappy to begin with.  It gives them a chance to express their love.  But they do little to animate anyone who is already happy in their personal life.

Policy-based ads appeal to the people with an intense sense of duty.  These are the people who believe that their own relationship to other people must be based on the desire to be useful.  Their desired solution to the prisoner's-dilemma-type problems is the cooperative one.

Getting back to the actual question at hand, do the ads work and why are the negative ads preferable to the other types of ads?
If they can get voters, who would not vote otherwise, to vote, then they work.  The types of people who are most susceptible to the negative ads are the ones who are content with where they are in life.  They are not looking for a new person to love (so type-2 ads won't animate them) and they are not looking to fulfill their sense of duty (so type-3 ads won't animate them).  But the negative ads create the perception that they may lose what they have (so type-1 ads will animate them).
Answer: An alternative theory:
Recent generations of politicians are increasingly the products of expensive political campaigns funded by powerful donors and parties.  Campaigning politicians spend a good deal of their time chasing and courting wealthy donors, and those donors usually expect something in return.  This environment obliges the modern politician, (however virtuous their intentions), to sometimes take on the role of corrupt sycophant.
Compared to normal people, corrupt sycophants have a fairly large attack surface, which leads to the modern comedy of political parties that secretly compel their own candidates' corruption, but take turns publicly advertising the opposing party's corruption.  That mutual and collective hypocrisy of opposing parties almost symbiotically balances each against the other and reduces both sides to a sort of crude sincerity.
But that balance requires that the general public become abstracted and disinterested enough to weigh their favorite candidates' broadcasted self praise against their opponents' broadcasted critiques.
Unfortunately, the recent confluence of advertising funded mass media consolidation and software filter bubbles tends to avoid such broadcasting, and instead narrowcasts to divided segments of the public attention, which atrophies these segments' capacity for disinterest and abstraction, thus breaking the mutually beneficial political party symbiosis, and replacing it with a competing and mutually unhealthy political party parasitism.
(Put another way, poorly regulated filter bubbles artificially turn otherwise normal people into paranoid bigots.)
Comment: I agree with what you are saying, but you take an awful lot of words to say it.  I do think the issue is more complicated than your long winded explanation though.  https://freakonomics.com/podcast/politics-industry/
Comment: @boatcoder, Thanks for the *Freakonomics* duopoly URL; there are commonalities, but this present SE question is focused on the abnormality of mutually adversarial campaign advertising, while an economic apologetic rather tends to *justify* it, hence my preference for a more neutral ecological analogy, (*i.e.* symbiosis).  If you have a specific suggestion, (like a before/after suggested revision), please send  it.
Answer: Psychologists tell us that fear and hate are two primordial feelings to which we readily react. The Nazis were most effective in using this tactic in the 20th century. Goebbels was a master of it.
But there is nothing wrong with pointing out the wrong doings of a politician.  It is the lying or the insinuations ("emails!") about the opposition that should be concerning.  Being informed is one of the cornerstones of citizenship in a health democracy in order to act/vote in our best interests, rather than being misinformed and mislead.
As you suggest indirectly, politicians should be focusing on arguments, ideas and policy proposals and how they will accomplish their objectives if elected, rather than just focusing on admonishing their opposition.
Btw, I would be suspicious of those who have nothing to offer but criticism of the opposition and little to nothing in the way of ideas, policies and proposals.  Where you find campaigns focusing on criticism you will often find a focus on rhetoric and slogans as a cover for their hidden agenda, which is usually more neoliberalism or corporatocracy.
Comment: Please, add a link/reference to the claim that "psychologists tell us" what you go on to claim that they tell us.  I am also not familiar with a good psychological definition of "hate" other than as a variation on disgust.  So if you could add a link showing that psychologists actually view "hate" as its own emotion, that would be informative.
Comment: @grovkin: this answer is too formulaic for me to upvote, but what you're complaining about is just silly; hatred is not the same as disgust in any serious psychological perspective and lots have been written about hatred separately  https://journals.sagepub.com/doi/full/10.1177/1754073917751229 (maybe "moral disgust" in one opinon/take, but there are plenty of other ways to classify/conceptualize hatred)


What is a reasonable, average file size of images edited with layers in Photoshop?

Question: When I edit photographs in Photoshop, I have noticed that the final file sizes average between 300mb and 700mb. I try to use smart objects whenever possible, and my files tend to have quite a few layers. I am a bit confused as to why my original 5mb .NEF raw images grow to several hundred megs as I edit them. Is this normal for .psd/.tiff files after edits have been made?
Comment: I haven't used photoshop in ages, but that seems quite large. Do you mean the size of the files on disk, or do you mean the memory footprint of the file when you're working with it?
Comment: The size of the .psd files roughly the image size * number of layers. If you have a lot of layers you will have large files, there's not a lot you can do about that.
Comment: So if you're using 60-140 layers on average, that makes sense.
Comment: Yes, size of the files on disk, and yes, I have quite a few layers
Answer: This is how big my .psd files are:

I have a lot in the 300-700MB range (mostly around 300MB). Some of these would be larger (probably a couple of gigabytes) but I flatten the layers occasionally to stop the files getting too large.
Is it excessive? I don't think so, if you have plenty of layers. Quite a few of my bigger files are panoramas. One thing I have noticed it that if you turn off "compatibility mode" when saving the files can be quite a bit smaller.
Comment: It also depends on what bit depth you work in. Working in 16-bit tends to help balloon your file size a bit as well. I would say I have had pretty similar experience to Matt here with Photoshop...400MB to 1GB files is not unheard of, and the more layer you add, the larger the files get.
Comment: Not being afraid of commitment is a big deal -- even a bit of merging and purging during a session can keep you out of the scratch disk while working on a big image or a complex comp. It helps a lot, too, to remember that PSDs are working files, not image archives -- if you spring out of bed at three o'clock in the morning on a random Tuesday twenty years from now thinking Uncle Fred's teeth were too white in that picture, you can fix a TIFF version (or rework the original RAW file). You don't need to hang onto the PSD forever.
Comment: Thanks for the feedback.  I do use a lot of layers, the images are big to start with, and I normally edit in 16-bit.  I try to be as nondestructive as possible; I used to merge occasionally, but I thought that might be bad form.
Comment: Image is unavailable.
Answer: I tend to do my edits and then flatten my file, keeping the edited file in TIFF/whatnot (and the raw, of course) in it's ready state. There is no point in wasting space just to keep the layer mask that you might reuse some day. If I want to redo my editing I tend to redo the whole thing anyways.
Answer: Keep in mind PSD files are considered "source files", so they're going to be huge however you look at it. Photoshop isn't concerned in the least bit about file size, so it will create 300MB+ files without so much as a warning prompt.
I would argue that if hard drive space is becoming an issue (and hard drive space is cheap these days) your best bet is to have an extra internal drive or external USB drive, or at least a separate partition on your drive for working on PSD files. This way you're not taxing your system disk as heavily, which will extend the life and integrity of your drive.
In my opinion quality is easily ten or twenty times more valuable than disk space if you have it, so I'm willing to let the space be eaten up.
If you want to get fancy, you could use a solid state drive for your system (which would include photoshop's swap space) and a typical hard drive for your storage; resulting in faster editing and plenty of room!
That all said, you always have the option to save to another un-layered format (TIFF/jpg at 100% for example, heck even PDF has a handy lossless ZIP compression option) if you don't need the layers handy. If you keep your original NEF, you can usually recreate whatever changes you need to.
Comment: Good advice about splitting SSD for system and HDD for storage, I think that's what everyone should do these days, not only for photoshop.


Can I use a Carte Bleu for French purchases made from the US?

Question: I am a French citizen and live in the US and I want to apply for and use a Carte Bleu from Societe Generale where I have an account. Will they send it to my address in the US and will I be able to use this credit card to make purchases from the US?
Comment: Isn't the Carte now a CB VISA and, therefore, accepted anywhere that VISA is?
Comment: How about asking them?
Comment: This doesn't answer your question, but SocGen have a lot of authentication provisions and I've found that my card got declined a lot on purchases in US for this reason. But I think the above poster is right, the card is in fact a VISA card, so it should ostensibly work.
Comment: Yes....it SHOULD work, however, I am always surprised by what SHOULD work in French banking, but doesn't. I have asked my bank representative about these issues but received nebulous answers to questions that I did not ask.
Answer: You could use it in the US, but there are fees for using your SocGen card outside the Eurozone. I find the SocGen card to be unreliable for uses other than with a merchant. Online my transactions are declined unpredictably, and contactless payments are similarly randomly accepted or declined.
As for whether they'll send you a card to the US... not sure. When we got out accounts last year, it was mandatory to pick up your "moyens de paiement" (e.g. Carte bleue and checkbook) at your local bank office. They've now changed policy and will mail cards to your residence (I got a replacement card in December this way -- but I live in Paris).
Further complicating matters is if your are a dual citizen of the US. The US requires non-US banks to collect and share data on American citizens' overseas accounts, and banks are hesitant to bother with the extra paperwork.
Comment: "Unpredictable", "unreliable", "randomly"....it sounds like I should have alternative means of payment readily available. And if I have to make a side trip to Paris to pick up this card personally, then it makes the Carte Bleu unattractive. I likely have to activate the card from a telephone in France, as well. I hadn't considered how sharing account information with the US might be a problem in getting a French credit card.
Comment: @KnobScratcher you already have the account with SG, so you are already exposed to FATCA requirements.  Getting the Carte Bleue won't change anything in that regard, nor will using it in the US.  If you live in the US, though, why not just get a US credit card?  There are plenty available that have no annual fee and do not charge interest or fees for purchases if you pay your bill in full every month.
Comment: You are correct and I must submit yearly DOJ forms as a result. However, having a foreign account is useless if the funds are unusable, or heavily taxed (or fined) if transferred out of the country.


Gift tax on sending money abroad from US

Question: I wired transfer about $20k to my father's account for family support (and the limit for gift tax is ~$14300 per person), in this case, can I claim that I'm actually supporting both my mother and father?
Comment: What is the nationality of your parents.
Answer: Are you actually supporting both your mother and father? Is the account joint? Is your mother aware of the gift and has control over the money same as your father? If you cannot answer (and provide support) yes to all these questions, then I doubt you could make such a claim.
If the fact that the bank account is only in your father's name is a mere technicality for whatever reason, and the money is in fact intended, controlled by and benefits both of your parents, then I believe you can.
See more details about gift tax in the IRS publication 950.
Answer: As long as you don't mind doing the extra tax paperwork, you don't need to pay any taxes, since the gift tax doesn't kick in until you've given someone several million dollars over a lifetime.
Comment: That is incorrect. You're probably referring to the "lifetime exemption", but the gift tax most certainly does kick in.


Easiest way to convert bitcoins to usd

Question: For someone in the USA what is the easiest way to convert bitcoins to usd while incurring minimal fees. I've heard of using mtgox with dwolla, or mtgox with internation wire transfer. But it strikes me as tedious to use dwolla. Why isn't there something like direct deposit, simple and fast?
Comment: You can ask someone who owns Bitcoins near you to sell them to you directly;).
Comment: The reason it's hard is because money services businesses have a number of laws to comply with.  Bitcoin is new, and that makes many of the money processors worried about how their operations will be impacted.  A simple one stop shop in the US will be very expensive to implement in the US because of state fees, SEC & related entity (SIPC) fees and required minimum capital.  Leveraging existing relationships keeps your fees low and distributes risk.
Answer: I recommend using the services of a user on LocalBitcoins with a high rating and high number of transactions completed.
Answer: You don't. In some cases, you may have to pay capital gains tax on that, which I think is running around 14%, but it depends on a few factors that only your CPA can answer. Well, you might be able to go unnoticed if you meet a guy in a cafe and he hands you cash, which is where localbitcoin type places on the web can hook you up.
Another route is to find a service that can get you Amazon and Walmart gift cards. See, with Walmart in the USA, you can even use the gift card at some select locations where they have a "Murphy's" out front in order to get fuel, and you already know some Walmart locations have grocery stores inside. So, if your major daily expenses in life are rent/mortgage, major purchases (requiring a loan, like a car/SUV/truck), groceries, fuel, and "stuff", then between Walmart and Amazon you can handle all that except the rent/mortgage and major purchases.
There are services to give anonymous ATM VISA cards like XMLGold.eu, but the IRS probably won't like that. Still, after I emailed and asked just because I was curious, XMLGold will definitely stick one in the mail or FedEx if you want, and even ship to the USA. Legal compliance, they realize, is your own deal.

Easiest way to convert bitcoins to usd


Is sending some datas in the data field safe?

Question: An airdrop ask to send it 0ETH with 150000 GAS and some datas in DATA field.
Is it safe?
What could be the aim of this transaction?
Thanks.
Comment: There's a lot of value in the first part of this question.  I suggest asking the second part of the question, some specific airdrop's transaction, separately. [My old comment: What data is being requested? If they just want to know address, then no data is needed as they can just use `msg.sender` (or `tx.origin`).]
Comment: Good point - what @eth said. Retracted my comment for safety. +1 his/her answer.
Comment: I stand corrected, good point @Eth. If you uncheck my response, I'll also retract. Thanks
Answer: Generally, no!  It can be dangerous.
If you are asked to send such a transaction, you should understand what is the source code of the address you are sending to, and what function you might be invoking with the data you are sending.
Do not send arbitrary data to some arbitrary address because that is like running an arbitrary program, clicking on an arbitrary link, opening an arbitrary email attachment, and it could all be malicious.
For example, you might have a lot of some particular ERC-20 token and if you blindly send data to some address, you might be approving an attacker to be able to steal all your tokens. (The address you are sending to would be the token contract, and the data would be invoking the approve function with the attacker's address.)
(It's possible that the data is static, but usually the data is an ABI encoding of what you will end up executing.)
Comment: This. The data value indicates which function of that smart contract are you going to execute and with which parameters.

You should trust the smart contract or be able to read the code.
Comment: @tjr226 That may be worth another question, and it would probably be a good idea to explain more what you want to do instead of keeping it very general. It sounds like you want to do something with an unknown contract rather than an EOA and others may have better solution for you. With unknown contracts you also have to be careful because contracts deployed with CREATE2 can get new code. A safe answer to your general question may need more thought.
Comment: @eth does the data being sent have to have the sender's instructions / authorization for the approval you mentioned?  Or is there a scenario where any random data (e.g. "hello world") actually gives the receiving contract that authority?  If the latter, then doesn't that basically imply the vulnerability you mention to any contract / any function?
Comment: @carlolm We agree and late reply as it was hard to understand your comment. The token case is an easy example and the main advice is to not sign a transaction or send data, without understanding what you are signing... For example, even if you have a virus scanner, it would probably be unwise to knowingly run an arbitrary program because the scanner might miss something even though it might be safe 99% of the time.
Comment: If I send short text messages in the DATA field of a transaction, something like "Hello World," is that also dangerous? Is there anything I can do to ensure that a text string won't run any additional EVM code?
Comment: @eth yup I asked it in a separate question. I'm interested in using some basic text inputs like "SEND X" or "RECEIVE Y" to flag Ethereum transactions, which will then be tracked in a ledger off the main Ethereum chain. the idea is sort of like colored coins
 https://ethereum.stackexchange.com/questions/98386/how-can-i-prevent-risky-data-fields-in-an-ethereum-transaction/98389#98389
Answer: Sending 0 ETH but with data just serves the purpose of creating/storing information (that data) on the blockchain, as well as related information (e.g. sender, receiver).
The gas is just the cost of sending the transaction.
Just note that the data you send is publicly available to everyone, so it's "safe" as long as you understand that and don't send any confidential information.


"13 Ghosts" voice effect

Question: I just want to find out if anyone knows how to create the "ghostly dialogue" in 13 Ghosts. What effects are used and how did they mix it together?
Comment: Maybe if I heard it I can tell you what it was. Where can I find a sample? You-Tube doesn't have the ghosts talking. The movie was released in 2001 so it can't too hard to figure out.
Answer: I haven't seen 13 Ghosts, but if you can find the clip let us know and we'll try decipher how they did it.
In the mean time, Jim Stout on Designing Sound shares a classic trick for creating scary voices.
Answer: 13 Ghosts is a guilty pleasure of mine! :) The effect used is the classic "reverse reverb". It doesn't really work in real time, but it easy enough to creat. Take your voice clip and reverse it. Now add a nice reverb to it - reasonably long decay, not too much early reflection, predelay to taste, keep the low end tame. Be sure to include enough time after the sample to get the whole tail of the reverb. Now reverse that whole mess AGAIN. Voila, the reverb comes from BEFORE the voice and gives you that effect. I've used that effect on a number of indie horror flicks!
Answer: A classic effect. I've never seen Poltergeist but by experimenting came up with the exact same effect many years ago. I love using it but rarely do my projects need such an effect.
My tool of choice at the moment is MondoMod to create a fluttery effect to a voice. Add on a phaser and instant computer voice.
UltraPitch can be used to create some cool effects beyond simply adding the harmonics to a voice.
Comment: You've never seen Poltergeist?! Some remarkable sound design in that film, courtesy of Richard Anderson and Steve Flick.
Comment: It's on an incredibly long list of films I really ought to see (and hear) but have never got around to it. I might just have to rent it now we've finally got iTunes films here in Ireland.
Answer: +1 on the reverse-reverb trick, and with the short delays as seen in Jim Stout's video it's extra creepy. I've done the reverse-verb thing a bunch, and plan to play with delays a bunch on the next project that needs it.
Answer: Howarth himself speaks about this effect in an interview on this website: http://constructinghorror.com/index.php?id=142 (it's the 7th part of the interview).

"13 Ghosts" voice effect


Is the visa-free entry to Schengen region multiple entry or single entry?

Question: I entered Germany in June, it was a visa-free entry (because I have an Australian passport) and I stayed 66 days before exiting to UK.  Can I now return to France and stay 24 more days, or do I need to wait until the 6 month period is finished and 90 days resets?  I'm not sure whether I am entitled to multiple entry or single entry, because of the Visa waiver for Australians all I have is the date and stamp on my passport from Frankfurt.
Answer: If you have a visa, it's either single-entry or multiple-entry. If you have visa-free entries, it works as if you were getting a new visa each time you cross the border. You can visit multiple times, as long as your total number of days of presence never goes beyond more than three months in a half-year.
Answer: This site answer your question: http://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1841750
Look:

The official rule for the Schengen visa is that, on the day you first
  enter any country within the Schengen zone, you start a 180 day
  "period", within which you can stay a maximum of 90 days in all
  Schengen countries. After you have racked up your 90 days (in one go,
  or in several chunks if you leave to non-Schengen countries & come
  back), you can't enter any Schengen country again until your 180
  period ends. And on day 180, no matter what, you have to leave
  Schengen territory (even if you haven't used all your 90 days), but
  you can then turn around & come back in again the next day & get a new
  90/180 day period. So: if you enter on day 1 & stay for 90 days
  immediately, you have to leave on day 90 & cannot re-enter any
  Schengen country until your 180 day "period" is up.

I hope this will be useful to you.
Comment: This doesn't look right: you don't have to leave Schengen on day 180 if you haven't used your 90 days. For example, if you visit Schengen on January 1st just for the day, then come back on June 29, you don't have to leave on June 30, you can stay for three months minus one day. (The [rules](http://travel.stackexchange.com/questions/20311/leaving-schengen-region-to-reset-90-days/20315#20315) say "three months" and "half-year", not "90 days" and "180 days", by the way).


Low-quality-answer flag declined

Question: I flagged this answer as low quality since it does try to answer, but misses the point completely: the question is how to make Firefox magnet links in Transmission, not how to manually do so. Was I wrong in flagging?
Comment: I see you didn't down vote it...
Comment: @Mateo I expected it to get deleted quickly so i didn't down vote. I'll do so now that it's still here.
Answer: My bad, upon looking at the post again, you are correct, it should have been deleted (and now is). I apologize. I'm not really sure what happened when I declined it, but I think I got the answers mixed up and thought you had flagged this one, which doesn't really fit the low quality flag.

A couple of other things I think I should point out:
Please do downvote bad answers, even if you believe they will be shortly deleted as there really isn't any reason not to (the reputation will be returned once the post is removed).
The "very low quality" flag (VLQ) is a rather confusing flag, both for the people using it and the moderators handling it. I could understand someone declining the flag because the post, at first glance, doesn't look like it meets the criteria. Even at a closer look I'm not sure VLQ was the best flag to use. The flag states:

This question has severe formatting or content problems. This question is unlikely to be salvageable through editing, and might need to be removed.

It didn't have severe formatting problems that couldn't be solved by editing. It might have severe content problems (as it doesn't even answer the question as asked), but I'm not really sure what severe content problems entails.
If I hadn't gotten the answers confused I would have approved it and deleted the answer. Next time though, (when there hopefully won't be any confusion on the moderators part) using a custom flag would be more helpful, especially since I regularly decline VLQ flags because of the aforementioned fogginess surrounding its use.
Comment: @muru Flagging it is appropriate, I was simply pointing out VLQ isn't necessarily the best option to pick :) (and this had nothing to do with me mistakenly declining the flag).
Comment: Yes, VLQ is somewhat unclear. I picked it as the answer isn't spam or offensive and does attempt to answer (even if it's the wrong question), and I usually use custom flags when I want to request something (ban for persistent spamming, for example). But [you're right](http://meta.stackexchange.com/a/122447/270345) - the right way to go about this is to downvote, not pester moderators.

Low-quality-answer flag declined


Interplanetary Agriculture

Question: What would be a good way to set up farms and trade among planets to ensure that the people of each planet are well fed?
Comment: No such thing would ever exist, the realities of physics dictate it never could, transport of anything other than the most valuable of luxury goods between planets in the same solar system will be prohibitively expensive in anything even vaguely based on reality (between stars? you can forget it), even the most casual back of the envelope calculations make that absolutely clear. So you need to explain your question better for anyone to be able to answer it, what "science" are you assuming & what are you hand-waving?
Comment: can you expound upon this a little. Why would there be a need to have a galactic bureaucratic control of the agricultural system? Why cant the local municipalities manage their own resources? Is there a major cash crop that the galactic government needs to ensure the supply is well maintained?
Comment: Trying for a massive edit to see if this can be turned into a question that works.  Carno, you will have to address the issues others have brought up.  I removed galactic, because that is nonsensical, but it still makes little sense to move food from planet to planet instead of growing it on site.  If there is a reason why it's impossible to even grow food indoors hydroponically, please state it.  Or so you mean a government policy about agriculture that holds for more than one planet.  Again, why?  If you don't like my edit, please change it back.
Answer: Firstly travel between planets needs to be cheap and fast enough to make it worth the effort of trading food. Ships need to be able to arrive in time to meet demand. There is no point turning up six months to two years after the famine. Unless travel is cheap and fast, planets have no choice but be self sufficient.
At best, food trade is likely to be preserved long life concentrates that can be made into food but take up the least amount of space for the most amount of meals. Plug the concentrates into a 3d printer and ten minutes later you have a piping hot steak and baked potato.
More than likely, trade will be in food producing equipment such as algae tanks, cricket farms and 3d food printers
Answer: Even on the relatively Earth like Mars, it will be very difficult for a long time. When exposed to water, Martian regolith releases perchlorate (bleach), making it very toxic. At some time in the past decade, scientists have grown potatoes in soil made from analog Martian regolith, but there is a long way from growing one potato plant to growing life supporting crops.
Each world would have to be evaluated first, and a treatment regimen for cultivating soil developed. Once you have a soil that is treated to where terrestrial plants can grow and produce edible foods, the process has to be expanded to cover several acres of land per person (yields will vary).
World's are large. Each world needs to be self sufficient for food. I can't see paying $10,000 per pound of potatoes, or even caviar.
Answer: If the planets had orbital rings which would allow for cheap transport between orbit and surface you solve one problem. You could use the rings to accelerate and launch cargo-pods or ships but they still need fuel to slow down/be captured by the receiver.
Fuel could be refined from moons or asteroids probably.
The thing is why? The travel times would be immense still. The amount of cargo shipped would still be low compared to what would be needed, especially compared to the size of population motivating an orbital ring.
And if you have that amount of industry/tech to build such structures you would be far better off building hydroponics and similar on site.
One situation that could motivate this would be a mother planet using its orbital ring to ship resources during colony setup but you would still focus on having the colony self sustained.
The economics just wont scale. You would probably figure out manufacturing/genetics in such a way that any planet would produce what's needed except special components and luxuries and even then it would still evolve fairly quickly to just needing the information to produce these.
You need a mechanism like the dune worm that produces something some special in such a difficult way to make it worth having that kind of trade.
Most in solar system trade would most likely be between space habitats/mining operations. Moving people, equipment and fuel.
So you either need to find a plausible way to make that expensive trade the only way combined with cheap transports to make it viable.

Interplanetary Agriculture


Why are explosions always used to represent the Big Bang?

Question: In documentaries the Big Bang is often represented as blackness followed by a big explosion with loud noises. This always feels cheap and falling short of explaining the origin of the Universe. Is this really the best way to get green-thumbs thinking about the origin of the Universe? Are there other, better, representations or analogies of the Big Bang? If so, how do they better describe the current cosmological model than the "explosion" analogy?
Comment: Explosions are more dramatic than video of rising bread dough. If you put poppy seeds in the dough, you'll get a Hubble-like constant for their rate of dispersion vs distance. An explosion yields a wildly different dispersion vs distance equation.
Comment: not a science question            .
Comment: My tongue-in-cheek response is that the animators always fall short (although I can't come close). A slightly better response is that space expanded, and, quite frankly, caused matter to "fly" apart - sort of (but not really) like an explosion. There's honestly nothing else like it. Rhetorically, how else can you express the beginning of space and time?
Comment: Where is the evidence? I've not yet come accross the comparison with an explosion.
Answer: No, it's not the best reproduction of explaining the big bang. Generally when you think logically, it was an explosion of matter, however it was not a fireworks show.
To best explain it simply, it is conceived as a singularity that rapidly expanded. An important thing to understand is that within the beginning of the expansion, the matter was quark–gluon plasma and opaque, meaning there was no 'BANG'. Intensity of the heat was too great to allow quarks to form hadrons. Hadrons comprise of baryons such as protons and neutrons, at the earliest stage of inflation protons had not formed, being a representation of the 'big bang' they aren't implicitly going to introduce these factors. A general representation if the bang factor itself, if the bang is presented as an inflating balloon filled with gas, it's not going to attract. To be a true analogue, the balloon would simply appear into existence (between 10^-6 sec and 1 sec), already expanded and have pockets of matter now cool enough to begin producing light, within the next 10 seconds electrons begin to form attracting photons and neutrons, the first atomic bonds (hydrogen) would continue for the next 380,000 years. Much of the earlier matter has been annihilated by antimatter and we begin to see matter in the form it is today.
In a nutshell, it's hard to present this theory when something just 'becomes', so I believe they use the explosion as a way of demonstrating the nature of forces rather than an analogue of mere inflation.


Is there any new water formed on, or brought to, Earth?

Question: I've found 2 sources stating that there is new water being formed on Earth.  The first site states that it is coming from hydrothermal vents in the sea floor.  The second site is basically saying that new water is being generated through biological processes.  However, to me, this just seems water that is already here coming up to the surface in the case of hydrothermal vents, or the rearranging of atoms into water molecules through biological processes that are already here on Earth.  Maybe this explanation is just semantics, but I'm also wondering if new water is coming here from meteors/meteorites.  To me that would be new water on Earth.  Is there any definitive proof of new water being formed on or brought to Earth?
Comment: [... the atmosphere is being hit by a 20 to 40-tonne snowball comet every 3 seconds. According to Frank, this is enough to add an inch of water to the Earth's surface every 20,000 years. Over the 4.5-billion-year lifetime of the Earth they could have provided all the water in the oceans.](https://www.newscientist.com/lastword/mg17523606-500-was-all-the-earths-water-brought-here-by-comets/).
Comment: @KeithMcClary I've just asked [What ever happened to the "Small Comet Theory" of water influx on present-day Earth?](https://astronomy.stackexchange.com/q/23794/7982)
Answer: Your explanation(s) sounds correct.
Your first article says as much.

There is a water cycle on earth that takes wet sediments deep into the
  mantle to be re heated and circulated back up as new sea floor. This
  is where the water in hydrothermal vents originates - it is NOT new
  water. However, there remains a possibility that some of the water
  emerging from the mantle has been there since the formation of the
  earth so some of it MAY be 'new'.

And your 2nd article
This is at least partly semantics calling it "new" water.  When we burn gasoline for example, the hydrocarbon structure becomes Water and CO2 - is that new water, or just re-arranging molecules by chemical reaction and fire?

I'm also wondering if new water is coming here from
  meteors/meteorites.

Water absolutely reaches the Earth by comets and meteors.   We're hit by comets and meteors all the time and comets especially are water-rich.   That is new water, though I wouldn't want to put an estimate on how much.  Too big a margin of error.
Earth also loses water by UV rays from the sun.   Most of the atmosphere the Earth loses is Hydrogen and most of that Hydrogen comes from Water.   Losing 90 tonnes of Hydrogen per day works out to nearly 800 tons of water per day, which sounds like a lot, but compared to the vastness of our oceans, it's a proverbial drop in the bucket, even over hundreds of millions of years.
So Earth adds water by comets and Earth loses water by photo-disintigration and atmospheric escape.   I've read that it's a net loss, not a net gain, but it's pretty insignificant either way.    Some articles suggest Earth has lost a pretty good share of it's water over billions of years.   I think there's a pretty big margin of error in those estimates, personally.
In 200 or 300 million years, as the sun grows a little larger and brighter, we might need to begin to worry about Earth losing too much water (maybe).  That's if we're still around, of-course.
Comment: Yes, and there is also the balance between water added to the mantle through subduction vs. returned to the surface via volcanoes. As the Earth very slowly cools, we might expect more water to be retained in the mantle.
Comment: @AndrewJonDodds  That's a good addition.   I didn't know that.
Comment: By my math, it would take something like 1.8 zillion years for earth to lose all of it's water.
Answer: New water introduction scenarios, other than through the biological processes mentioned in the question:

When ice(H2O) meteorites/asteroids enter Earth's atmosphere they melt into water
When Meteorite containing Oxygen compounds reacts with hydrogen in the upper atmosphere, and creates water
If Meteorite containing Hydrogen compounds reacts with oxygen in the lower atmosphere, and creates water [unlikely]
If Earth passes through a comet's trail or nebula containing Hydrogen or Oxygen, which reacts with Earth's Hydrogen/Oxygen to create water [unlikely]
If Earth passes through a comet's trail or nebula containing ice(H2O) [unlikely]
If the Hydrogen from the upper atmosphere somehow meets Oxygen in the lower atmosphere [very unlikely]
Answer: Yes, ever tried a vinegar and baking soda reaction, well that reaction produces a little water along with Products. One of the products is sodium acetate (NaC2H3O2). The other products are water(H2O) and carbon dioxide (CO2).


What are the physical reasons behind noise/errors in quantum computers?

Question: We know that the current quantum computers are noisy/error-prone. They are susceptible to gate errors (single qubit and multi-qubit), decoherence (relaxation and dephasing), readout error, etc. I want to know what is/are the underlying physical reason(s) behind each type of error. Answer for one type of qubit (say, superconducting qubit) is perfectly okay.
Answer: Quantum computers are susceptible to these errors/noise because of physical disturbances. An example of this is if some molecule in the surrounding air were to bump or approach the qubit it would transfer some kinetic energy and maybe affect the state. Another example is if a qubit interferes with any adjacent qubit, if they "bump" into one another their wavefunctions can constructively or destructively interfere to give an odd result. This reason is why adding more qubits into the system greatly increases the noise. There's much higher chances of a qubit "spilling over" onto another one because there's more energy contained. These are some of the reasons why quantum systems are super-cooled and kept in a vacuum.
The way that I like to imagine it physically is sort of like the quantum "egg carton" or ions trapped in an optical lattice. The qubits are stuck in those craters but as you add more it becomes harder to keep them from interacting with other ones. Hence placing more qubits into these craters and conducting large amounts of operations increases the probability of error.


In India, what is the difference between "local flying area" and "airspace"?

Question: Can anyone define what is a "local flying area" and an "airspace" and what is the difference between the two? It would be good if the definition is as per Indian rules.
Comment: Welcome to Aviation.SE, you have this question tagged as both FAA and DGCA but you are asking about Indian rules in the body. You may want to remove the FAA tags as they are a bit confusing. If you are looking for FAA answers as well you should add that to the body as you may get more answers that way.
Answer: A local flying area is airspace that is designated by local air traffic control for general flying not involving circuits and landing. In the US it is something that is loosely referred to as "the practice area." In this area aircraft can perform practice and other maneuvers, and air traffic control will be aware of it and can warn other aircraft to be on the lookout for this. In India it is common for these practice areas to be segregated for flying school aircraft, and medium to heavy aircraft.
To put it another way, all local flying areas are part of a country's airspace, but only a fraction of the airspace is designated as local flying areas. I hope this helps.


Who decides how fast commercial aircraft fly: the pilots or ATC?

Question: Once a commercial aircraft is in the cruise phase, who determines the speed of the aircraft?
Do pilots have the authority to fly at up to the maximum permissible speed of that plane, or does ATC decide on that depending on the approximate time it will take to reach the destination? Is it stated in the flight plan that the pilot cannot go beyond some specific speed even if the aircraft is capable of it?
Comment: @TylerDurden That statement is correct, but incomplete: When operating under positive control (in the US that generally means class A & B airspace, on an IFR flight plan, or on movement areas of a controlled airfield) pilots are required to obey instructions given to them by ATC, absent an emergency or some other really good reason to justify a deviation from their clearance. While a pilot *CAN* do whatever they feel like with the aircraft by virtue of being at the controls if they simply ignore ATC clearances they don't like it can lead to some *unpleasant* conversations with the FAA.
Comment: Non-pilots often seem to have the idea that controllers are some kind of gods that boss around aircraft. That is not how it works. The controllers are there to assist the pilots, not boss them around. Pilots may follow the recommendations of a controller, but the pilot ALWAYS has the final say and power to decide.
Comment: @voretaq7 Agreed, if the pilot actions trigger a review and it turns out he deviated in a way that compromised safety or showed poor judgement, gone goes the license. Keep in mind though that controllers screw up all the time or make blind instructions that are just wrong for some reason, so it is very common for pilots to reject instructions, and I have done so on many occasions.
Comment: @TylerDurden It's a bit off topic, but I am reminded of bumper stickers on some cars in airport employee parking lotS in the early 1980s before the controller strike. They said "CONTROLLERS TELL PILOTS WHERE TO GO." The stickers disappeared after the strike was broken.
Comment: Yes, pilots are in command: during a DeHavilland Comet flight, Elizabeth von Battenberg was one of the passengers, the pilot wanted exhibiting the airplane's performances, and increased power to top, to gain airspeed; experience was aborted when the flying machine started uncontrollable vibrations...
Answer: ATC can assign speeds en-route for separation or in the TMA area for sequencing aircraft onto the approach. Speeds en-route in upper sectors are assigned using Mach numbers:
R: "DLH123, maintain speed Mach .78"

In the TMA area, aircraft are sequenced for an approach and reduced to similar speeds to maintain lateral separation. These restrictions can be paired with conditions, until when the speed needs to be maintained:
R: "BER456, reduce speed 210 knots"
R: "BER456, cleared ILS approach runway 24,
    maintain 170 knots indicated until outer marker / 5 DME"

Certain approach or arrival charts list maximum speeds for certain turns, marked with MAX 210 KIAS, indicating that this turn should not be flown with more than 210 KIAS to make the radius.
Speed restrictions imposed by ATC need to be maintained until cancelled by the ATC unit:
R: "DLH123, no speed restrictions / resume normal speed"

The pilot however is responsible for ensuring a safe flight and can report that he is unable to follow the instructions due to performance limitations.
A: "DLH123, unable to comply, indicated airspeed will be 150 knots"

There is also legal considerations when it comes to aircraft speeds, such as general rules for traffic below certain altitudes or in some jurisdictions, only for certain airspace classes (related: What is the speed limit in European Airspace).
The FAA CFR 91.117 says:

§91.117   Aircraft speed.
(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

The German LuftVO however rules that a speed limit of 250 KIAS below FL100 only applies to VFR and IFR aircraft in airspaces class D,E,F,G and only to VFR aircraft in airspace class C. IFR aircraft in airspace class C do not have a speed limitation.

Regarding the general authority over a flight, see the related question:
Who has the higher authority, the pilot in command or ATC?
Comment: It's worth noting that the 250 kt limit below 10,000 ft in the U.S. does not apply if the minimum safe speed for the aircraft is above that, which is the case for a heavily loaded 747-100 or -200 and probably for the later models as well. Also, if you're icing heavily below 10,000 and expect to be there for awhile, increasing speed to above 250 kts to raise the temperature to stop the icing was normal. Also, if you're below 10,000 and get 12 miles off shore (statute as I remember), the 250 kt limit did not apply prior to the year 2000. I don't know if that's still true.
Comment: Standard ATC phraseology for speed does not include "knots" nor "indicated". KIAS is implied.
Comment: @SteveKuo Corrected for the speed assignment, knots is used however according to my AIP. In the advice that one is unable to maintain a speed, the word "indicated" is used.
Comment: When on Oceanic crossings with no radio coverage, at the entry point to the track the pilot is given a clearance which includes the speed.  The aircraft is expected, unless safety overrides, to maintain that speed since it is the only way that the controller knows where the aircraft is in relation to other aircraft on the same track.  They can also estimate the aircraft position.
Comment: @Simon Should I incorporate that into my answer? Do you have an example/source for phraseology? I am using a German AIP for the most parts, which obviously omits oceanic clearances...
Comment: @rbp I added that part about airspace limitations.
Comment: i think you can improve this already very good answer by breaking it up into 5 airspeed limitations: routing (charts and plates), airspace (eg US below 10K), operational restrictions (imposed by the airline), ATC clearance, weather (eg temps, turbulence, etc)
Comment: oh, and holds! http://en.wikipedia.org/wiki/Holding_%28aeronautics%29#Speed_limits
Comment: @rbp weather I am not really an expert to phrase that properly. You want to give it a try and edit my answer?
Comment: @SteveKuo Do you have a reference?  In the UK at least, all speed instructions are suffixed with "knots" to ensure no confusion with headings.  E.g. "turn left heading 220 degrees speed 200 knots" is much safer than "turn left heading 220 speed 200".
Comment: @SentryRaven I could not find an official reference, but this is a good link.  In this document is an example of a clearance - `"ACA865 is cleared to Toronto via Track Bravo 283 from Mimku (56 N 010 W), maintain Flight Level Three
Five Zero, Mach Decimal Eight Zero."
`http://www.theairlinepilots.com/forumarchive/areaprocedures/natops/natclearance.pdf
Comment: @Terry  In the UK, the only airspace I know, at the controllers discretion, clearance for speeds higher than 250kts can be given.  Is this true in the US?
Comment: @Simon If it's a case of your normal operation being less than 250 but you are capable of exceeding 250, I really don't know. FAR 91.117 (a) says "Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h)." I think, but am not sure, that a controller is acting at the authorization of the Administrator and thus would have the authority to issue such a clearance. You might ask this as a regular question and we'll see if someone knows better?
Answer: Pilots will mostly set the speed they want. In cruise, the planes tend to be further apart, and speed is less critical. Different planes fly at different speeds, and ATC usually uses altitude and heading as the primary means to separate them.
However, ATC will sometimes ask for different speeds as another way to separate aircraft. If a fast plane that wants to climb is underneath a slower plane, ATC may have the slower plane slow down a bit, and the faster plane speed up a bit so the faster plane can get far enough ahead to climb.
As the plane nears its destination, speed becomes more likely to be a factor. If there are delays at the destination, ATC may tell the pilots to slow down to minimize time spent in a holding pattern. This may also serve to sequence planes in for arrival, where ATC may ask for faster or slower speeds. Speed restrictions are much more common in arrival, which SentryRaven's answer describes.
Answer: ATC is providing collision separation services only. It is the responsability of the pilot to operate the airplane and to keep it under a safe flight envelope. So, speed:pilot, Heading-altitude:ATC :)
Comment: This is incorrect: there are many cases where ATC can and does assign a speed (it is extremely common in the terminal environment to ensure apropriate separation on approaches).
Comment: speed is commonly assigned by the atc in order to fulfill their aforementioned role :) This is mainly needed on approach, true. Thank you @voretaq7


Can A Raspberry pi mine bitcoin without an ASIC miner?

Question: I want to know if a raspberry pi can mine bitcoin without using an ASIC miner.
Answer: You certainly can compile a Bitcoin node on a Raspberry Pi, and it will act as a fullnode relaying transactions for the network.  For mining, while it probably would work technically, the chances of you ever mining a bitcoin are so low that its probably a waste of time.
You can run other coins based on PoS on a Raspberry Pi though and make money that way, I personally use Raspberry Pis as my Gridcoin and SolarCoin staking nodes.
Answer: You want to compare a budget mini-computer that has the performance of a 5yo desktop to a system dedicated to just the single process of mining?
You could buy a lottery ticket for that 75$. It probably has the same chance of running a profit as mining on a rpi.
Comment: I think you'd be better off buying the lottery tickets.
Answer: Mining is about trying as many possible block candidates as possible. Your miner's proficiency at this task mostly corresponds to the amount of SHA-256d operations it can calculate. Raspberry Pis are computationally extremely weak hardware and are not optimized to run this operation. ASICs in turn, are application specific integrated circuits that have the SHA-256d operation baked into the hardware on the chip.
Your Raspberry Pi has very little computational power and a comparably bad energy efficiency. Chances are that you could run it for centuries without getting any reward.


How can I log into a different Google account?

Question: It only shows one of my Google accounts. I want to log into a different one but I don't want them connected in any way. What do I do?
Comment: You want to be logged in into both of them at the same time?
Answer: If you mean multiple Google accounts at the same time...
In the top right corner of any Google window (mail.google.com for example), select your user icon and select "Add account". (next to Sign out)
Log into another gmail / apps account.  Follow any instructions if multi-account login is not enabled.
Once this is completed, you can use that same process (select icon) to switch accounts.
The only 'connection' between accounts is that if you log out, you log out of all accounts.
You can be logged into 4 accounts at the same time.
Answer:
Sign out of your account.
Click Sign in with a different account.
Click Remove.
Click on the X next to the names of other Gmail accounts.
Click Done.
 Dialog will appear with "You've removed all accounts."
Click Done.
Comment: It's not necessary to sign out. See @kevan's answer below.
Answer: If you don't want to use Kevan's suggestion, use a second browser profile.
For example, you can start firefox with the flag -p from a command line, and it will let you create a second profile. Then you can log in into the one account from one browser window and into the other from the other browser window. You will have to start firefox with the flag --no-remote to be able to open a second window with another profile. It is a good idea to use a different theme in both, so you don't mix them up. (They behave like completely separate installations, you must install all addons separately, and adjust all settings the way you want them).
Chrome supports profiles too. I don't know about other browsers.
Be aware that many sites you visit will gather lots of information about you. The fact that you are using the same IP address, same MAC address, and are logged in at the same time is enough for them to be absolutely sure that it is someone from the same household, and quite confident that it is the same person. So, while officially there won't be a known connection between the accounts, Google's algorithms which work with recognizing identities of visitors (e.g. algorithms for personalizing ads, for suggesting contacts on Google+, etc.) will know that there is a connection.
Comment: For Firefox, you can use MultiFox addon to help you create and manage many profiles.