Entering USA under VWP for 3 weeks and continuing to CAN for a 3-month stay?

Question: Similar questions were asked, but they were still different from my situation. I wanted to enter USA under VWP stay there for about 3 weeks, cross over to CAN where I would stay for 3-3.5 more months and then return back to country of residence from CAN. Is it necessary to apply for tourist visa for US? If the time altogether was less than 90 days, would it be OK? Alternatively, what if I flew to Costa Rica after staying in USA and then from CR straight to CAN? I don´t feel like going thru visa application procedure as it would cost money and would be tight with time.
Many thanks
Comment: What is your nationality? If it qualifies for the VWP, then why do you think this plan might require you to get a visa anyway?
Answer:
I wanted to enter USA under VWP stay there for about 3 weeks, cross over to CAN where I would stay for 3-3.5 more months and then return back to country of residence from CAN.

If you follow the above plan, then you will not overstay your stay in the USA under the VWP. The USA would consider you "in" the country for only your initial 3 weeks. As long as you are eligible for the VWP, you do not need a tourist visa.
You would only encounter a problem if you tried to re-enter the USA after your 3+ month stay in Canada. In this case, your entry to Canada would not reset the VWP 90-day clock.
Answer: You appear to be confusing two separate things.

The VWP allows you to make a visit of up to 90 days to the USA.
If you go to another country in North America and then go straight back to the USA, it counts as a continuation of the original visit, not a new visit.  To start a new visit, you must leave North America before returning to the USA. In this context, "North America" means the USA, Canada, Mexico and the Caribbean.

You are covered entirely by point 1: you will be in the USA for less than 90 days, then you will leave and not come back. You can stay in Canada for as long as Canada will allow you to and the USA doesn't care, as long as you don't go back to the USA without leaving North America first.  (And you don't plan to do that: you plan to return home after visiting Canada.)
Point 2 says that you cannot spend three weeks in the USA, then spend three months in Canada, and then go back to the USA.  The USA treats that as a continuation of your first visit, which would make it longer than 120+ days. Since you're not planning to do this, it doesn't affect you.
Coincidentally, the US Customs and Border Patrol website (the same page I linked above) specifically uses Costa Rica as an example. If you did fly to Costa Rica, that would reset the clock and your return to the USA would count as a separate visit. However, US immigration is very sensitive about people trying to game the system by spending 90 days in the USA, leaving briefly and then trying to return.


Why do you have to accept a licencing agreenment before installing Java but not C++?

Question: There is a license to use Java which you must accept before installing. Why isn't there one for C or C++? If there is, where can it be found? I'm guessing it has to do with how Oracle owns Java, but in a sense can't you say whoever makes the C++ owns it?
Comment: C and C++ are two international standards maintained by ISO in cooperation with IETC. The copyrights are formally owned by the National Bodies. But that's the documents describing what C and C++ mean, not software.
Answer: The reason for this is simple: You can't install C or C++. C or C++ is just a programming language and C/C++ code compiles to machine code. Machine code can directly be executed by the processor (CPU) in your computer.
Java, however, is normally compiled to byte-code only a Java Virtual Machine can execute. And this Java virtual machine is what you get from Oracle and Oracle wants you to accept a license agreement.
You likely also have accepted some kind of license agreement when you began using or bought your computer. That's the same you did for the Java Virtual Machine, but this time for your whole computer, which includes the processor that is responsible for executing the machine code.
Java in this context also refers to the Java libraries that ship alongside the JVM. While C or C++ also have standard libraries they are part of your operating system and you have agreed to a license covering them when you installed your operating system (or began using it).
Comment: You **do** need to install a C or C++ compiler, and while there are some technical differences with a VM, for the purpose of this question those differences are unimportant. C or C++ don't just work "magically".
Comment: A good explanation, but perhaps you could draw a comparison to help the less technologically- or linguistically-inclined? Maybe along the lines of "why do I have to pay for getting the typewriter but not for using English?"
Comment: @Carpetsmoker Yes, for a compiler. But C and C++ are still just languages. And that's what the question is about. And no, the difference is important here. Oracle licenses the "Java SE Platform" to you. That's the VM. You don't need to license anything to run C/C++ executables as long as you possess a compatible processor (which might come under a license as well, of course).
Comment: I disagree with his point too, you do need a compiler to run C/C++. But I guess when you install a compiler, it has it's own license agreement.
Comment: @Toofast12 Of course you need a C/C++ compiler and as you said every compiler comes with a license. Here's LLVM's for instance: http://llvm.org/docs/DeveloperPolicy.html#license and here GCC's https://gcc.gnu.org/onlinedocs/libstdc++/manual/license.html. If your question was actually about compilers, the answer is simple: Every reasonable compiler comes with a license. But your question sounded more like it was about the languages and not about compilers. Nobody "owns" C/C++ whereas Java is a registered trademark of Oracle.
Comment: @Toofast12 And just to clarify: you can't run "run C/C++" directly. Neither can you directly run Java. With both languages *you just can run the executables*. (Of course, there are some fancy interpreters that can do that, but that's off the point I guess) And you *do not* need to have a C/C++ compiler installed to run C/C++ executables.
Answer: The Java Licensing Agreement
The Binary Code Licensing Agreement for Java SE relates to your right to reproduce internally without modification their Java Virtual Machine (the thing that will run your compiled Java code). Among other things, it prohibits from making derivative works that "modify, or change the behavior of classes, interfaces, or subpackages that are in any way identified as 'java', 'javax', 'sun', 'oracle'". It also generally prohibits redistribution of the source code for the Java API.
C++ has similar protections
Analogous protections do exist relating to C++.
The runtime machine is protected
The design of your computer's processor is protected by patent and copyright (by Intel, or AMD, etc.), and you don't have permission to copy it. The reason you don't need an explicit license like you do for the Java Virtual Machine is because it is a physical thing that you legally possess, and no reproduction rights are implicated when you use it. Also, it would make no sense to call this part of C++ because it is used by every program that runs on your computer. But, it is protected, like the Java Virtual Machine is protected.
The compiler and standard libraries are licensed for your use
C++ requires a compiler to turn the code you write into an executable format. It also includes library code that implements a bunch of standard functionality that is available to the programs that you write. This compiler and library code are protected by copyright, and only available to you because of a license.
For example, a very popular implementation of C++ is GNU C++. Its C++ compiler (g++) and standard library implementation (libstd++) are distributed under the GNU Public License with a section 7 exception that allows "[proprietary] programs to use [...] the
header files and runtime libraries...". Another C++ implementation, Clang/LLVM, is licensed under the BSD License. There are also many proprietary C++ implementations.


Attending non-frum event

Question: Is it permissible to attend a non-frum event, such as a wedding or bar/bat mitzvah of a family member or friend?
Comment: I think this question needs to be clarified. Unless there is some Halachic impropriety that is happening at the event itself or some Halachic problem inherent in the event (ie., intermarriage; wedding held on Saturday; wedding held in a church; etc.) it is unclear why there would be any reason to say that someone cannot attend an event that isn't "frum". Is the concern a lack of a Mehitzah at the Bar Mitzvah? Is it the microphone on the Bimah? What exactly is the issue you're asking about?
Comment: Debbie, Welcome to mi.yodeya, and thanks very much for the interesting question. Please consider registering you account so that you can take full credit for your contributions and have access to all of mi.yodeya's features. NOTE: This will become easier to do by Tuesday: http://meta.stackexchange.com/questions/3793/whats-new-in-beta-6
Comment: Do you mean if it's held inside a non-Orthodox synagogue's sanctuary?  Or are you concerned with other issues, even if it was at a hotel, home, etc.?
Answer: This is just my guess on things from what I've seen.
There can be a lot of issues going on in each case, so it's worth taking an honest assessment of the full situation, and talking with a rabbi who's both knowledgeable and understanding.  If both you and the event host demonstrate genuine caring and communication, that can help a lot of things too.
I think the overarching principles here, in descending priority, are:
A.) We can't violate strict Halacha.
B.) We can't give the message "oh Halacha is totally optional."
C.) Attending may fulfill a mitzva as it could be a form of respecting parents; kindness to those in need; or gratitude the hosts deserve.  But be honest and careful; it's easy to rationalize anything into a mitzva if you want to.
D.) It's important to maintain our connections to non-observant Jews.
E.) It's important that non-observant Jews see that observant Jews are nice, caring, and "normal."
Otherwise, my guess is to respect C, D, and E above, so long as they don't violate A, B, and E.  Examples that could potentially violate A, B, and E, and are thus more problematic:

An event that will force you to violate Shabbat, kashrut, etc.
An event whereby you are facilitating others' violation of Shabbat, kashrut, etc.  The definition of "facilitation" is well-discussed in the rabbinic literature.
The entire event is Halachically negative.  E.g. an out-of-faith marriage.
An event that will put you in a situation whereby keeping Shabbat, kashrut, etc. will make you (and therefore all Orthodox Jews, of course) look like an evil, heartless, stick-in-the-mud.
A prayer service held in the sanctuary of a non-Orthodox synagogue.  I've seen plenty of good Centrist Orthodox Jews attend such events; nonetheless, when I'd asked Rabbi Yehuda Henkin about a specific instance of this, he said, "I can't give you a psak without full understanding of all the pertinent details."
A ritual that actively thumbs its nose at traditional Jewish thought and practice.  It could be a Jew marrying a Jewess at a hotel, but if the officiating rabbi will use it as a big soapbox to attack Orthodoxy (in my experience, this is less of a problem in Conservative than in Reform/Reconstructionist), does your presence imply agreement?  This could be less of a problem if you're Joe (or Judy) Orthodox in the middle of a big crowd, and more a problem if you're a high-visibility figure, a rabbi, and/or someone known as a Torah scholar.

If the hosts are making an effort to accommodate you, that can be a reason to attend (and not violate C, D, and E), but it has to be balanced with the above concerns.
One more note: Orthodox rabbis (even some fairly right-wing ones) are used to getting these questions.   Otzar HaPoskim has the case of a BT woman attending her brother's wedding, at which she'll be expected to kiss him.  (I guess it's just a huggy-kissy kind of family.)  Answer: it's not so much Halachically prohibited as frowned upon, which gives some leniency.   But better to explain the situation to him if you can.
Comment: Kissing a brother is "frowned upon"? Really?
Comment: Grown-up siblings of opposite gender are not supposed to kiss each other.  A WOMAN shouldn't kiss her brother.  See Rambam Isurei Biah 21:6, and this: http://mi.yodeya.com/questions/3069/what-are-the-halachic-boundries-between-a-brother-and-sister/3072#3072
Comment: It's also worth noting that there isn't an instance in the Tenakh of a sister kissing a brother, or vice versa.
Comment: @JudahGabriel, lots of stuff doesn't appear in _Tanach_ but is fine. That's not particularly telling.
Comment: See Od Yosef Hai Parashat Shofetim (written by the Ben Ish Hai) where I believe he is even Oser hugging and if I remember correctly he says to avoid even touching.
Answer: This sounds like the sort of question that you really need to discuss with your Rabbi, since there are lots of different issues in play, and how they interact could vary a great deal, depending on the circumstances and on the people involved.
I'll enumerate some of the major issues that could come up. Note that I'm not saying that all of these are necessarily important issues in all situations.

Entering a religiously liberal synagogue's sanctuary.
Attending a religiously liberal congregation's services.
Attending or participating in religiously liberal para-services at celebrations.
Participating in a wedding conducted using religiously liberal procedures.
Attending an event at which non-Kosher food will be served.
Attending an event at which men and women will be dancing together.
Maintaining a relationship with one's family and friends.
Avoiding embarrassment to other people.
Helping celebrants (especially a bride and groom) enjoy themselves.
Sanctifying God's name by giving people a good impression of religious Jews.
Comment: Nice going, Isaac!  Looks like we both wrote up our thoughts around the same time -- and they're pretty similar.
Comment: Yeah, but you fleshed it out a lot better. I like how the overall message from both of us is "it's complicated; ask your Rabbi."
Answer: The Gemara speaks harshly about those are invited to a Seudaat Mitzva (according to R' Mutzafi this means weddings or Beritot) and don't attent. However, HaRav Ovadia Yosef Shelit"a writes (Yabia Omer vol. 4 Yoreh Deah 19) that if there are going to be "Inshi Delo Maali" e.g. non-frum people it's better not to go. (I heard this from Rav Meir Eliyahu Shelit"a).
Comment: "if there are going to be": I suspect almost every event I've ever been at has had _some_ such.
Comment: @msh210 I don't know what to tell you :-)
Comment: @msh210 I think he meant making problems.

Attending non-frum event


Wall in middle of tile floor: grout lines don't match

Question: A contractor is installing tile in the first floor of my house. The floor plan is open, with the living room and kitchen separated by a wall that spans a portion of the floor. The installer laid tile in courses on the 'north' end of the wall, then continued to lay going 'south,' where the wall divided the area into two rooms. At the 'south' end of the wall, the grout lines don't line up. (See diagram.)  Is this acceptable, or should I tell my installer to do it over?
Comment: Can you send real pic?
Comment: Up to you. You are paying. I would hope that the contractor could and would agree that the anomalous alignment is truly undesirable and correct it, but .... that isn't for us to negotiate.
Answer: This is indicative of a poor initial layout, perhaps due to inexperience. An experienced tile setter takes note of the areas where defects (like grout lines that can't line up, small or thin cuts, discolored tiles, etc.) would be most visible and makes sure things are perfect in those places, hiding the inevitable problems elsewhere.
If the tile had been properly laid out before setting it, the lines would be perfect across the open areas. Small differences in tile spacing are normal but are normally hidden by "pinching" or "spreading" the grout lines in places where it won't be noticed.

should I tell my installer to do it over?

I would, or I would insist on a significant discount due to lame installation then hide it with an area rug or something...

This is an example of why you should hire reputable contractors who are not shy of providing references, or hiring out of the local guild. You get what you pay for sometimes...


Why do newspapers use multiple columns?

Question: This might not be the right place to ask, but I was wondering why newspapers use multiple columns? Does it take up less space, or is there a visual reason?
Answer: Linked below is a short but good read summarizing different studies on line lengths.  Studies were done as far back as the 1880s demonstrating that optimal line-length for reading was between 3.6 - 4 inches.  Even 50 years later, this was still the deal:

One of the best studies was done by Tinker and Paterson in 1929. Using 10-point black type on white paper, they found that line lengths between 3 inches and 3.5 inches (75 to 90 mm) yielded the fastest reading performance. Paragraphs with line lengths of 7.3 inches (185 mm) were read slowest. The authors proposed that longer line lengths obviously require greater lateral eye movements, which seemed to make it more likely that users would lose their place within the text.
Bob Bailey, Ph.D.
UI Design Newsletter – November, 2002

Bailey mentions that this held true until computer monitors became more prevalent.  He cites several studies in the 1980s & onward indicating that, on computer screens, longer lines are read faster, while users prefer lines of 4 to 5 inches in length (the fact most relevant to your question). Other research shows that more whitespace improves comprehension (Chaparro, Baker, Shaikh, Hull, and Brady, 2004).
Comment: The problem with this answer is that most newspaper columns are actually overly narrow compared to most (admittedly specious) line-length studies. Most newspapers are in the 1.5-2.5" length.
Comment: I wonder why computer monitors are easier to read?
Comment: I don't think it's true that longer lines are easier to read on a screen. I think the problem is that with columns, the column height may cause you to scroll often (which is not ideal) so it is difficult to implement a multi-column layout on a screen, which is why they are not as prevalent.
Comment: @Tyler Could be loads of different variables...  screen-resolution/font-display-size, working distance, environmental variables, age of participants, literacy rates, ...the list goes on.  I'm sure the studies account for these things, but I haven't read them so your guess is as good as mine.
Comment: @DA01 Interestingly, according to [Modern Advertising by Earnest Elmo Calkins, Ralph Holden (1905)](http://www.lexic.us/definition-of/newspaper_column) "The standard newspaper column is 13 pica ems wide or 2^ inches."  So even at the time of the studies linked above, newspaper column widths were much smaller.  Your answer is certainly more correct...
Answer: Advertising. While it's a noble idea that it was done for readability, newspapers, in general, have columns that are overly narrow compared to most given readability information/data.
Having multiple columns allows for a very versatile ad grid, and, traditionally, newspapers were in the business of selling ads.
It also allows more stories to appear on the page at once (all being continued elsewhere). This is partially to get more headlines in view of the reader, but also allows for a lot more flexibility for the page layout team to get all the ads to fit. When a newspaper is laid out, all the ads are first put into place, and then the content is flowed around it and, quite often, re-edited to fit the column lengths available.
The bonus side effect is that a reader is now scanning not only across multiple columns (and thereby being exposed to multiple ads) but also has to now flip to multiple pages (again increasing the odds of seeing a particular ad).
And if you go WAY back in time when type was set by hand and/or linotype, you needed a continuous column of type for easy typesetting. Ads were locked up completely separate from the text and you didn't have the ease/opportunity to flow text around elements within the column itself. Keeping columns narrow simply offered the most flexibility for both the ad layout and the typesetting.
Answer: I am amazed that not one of the responses gave the ACTUAL reason which is that it is far easier to work with shorter line lengths when it comes to the type set. This is especially true with the Linotype machine which revolutionized the newspaper industry. These devices actually formed the type set plates as they went along, line by line, creating molds that would be used to form the type. Much easier to make molds that were no greater than 2 inches worth of characters. And before that when laying out the type set was done by hand, it would be much easier to work with smaller lines at once.
Comment: @go-meek no, that's not totally wrong. Advertising is the primary reason the multi-column layout exists well into the digital age. Ads are always the priority, with copy following. The multiple columns allow for the most flexibility in both--selling the ads, and flowing the copy. Historically, hand setting type was a factor, for sure, but it's been many decades since we've last set hand-type for newspapers. Anyways, I'm not sure why you feel you need to be defensive. I in no way said it wasn't a good answer.
Comment: +1 I'm also amazed no one mentioned this as the real (simple) reason to use columns was entirely technical. Unfortunately, sometimes people elaborate by googling and this was not on google; that's why they only found stuff about "readability"! Very misleading. https://youtu.be/F1qlSGcsJn4 (Typesetting - Manual Press Print and Page Layout)
Comment: Note that I did mention the typesetting-by-hand issue in my answer, though yours is definitely a bit more detailed in that particular aspect.
Comment: @DA01 Not a bit more detailed, it is detailed and on target. You hypothesized on advertising which is totally wrong. That's why this question needed a bounty, the answers are misleading even though they have high scores. At least the "easy to read" part is partly right today for stock market data and classified ads, for obvious reasons.  Advertising can use any amount of columns and are placed pretty much anywhere. That grid system isn't exclusive to newspaper layouts and todays tabloids/newspapers don't always restrict themselves to the "small columns format". This is a good simple answer!
Comment: @DA01 Not being defensive to prefer facts over beliefs. Simply not true advertising is the priority, not all newspapers or magazines have inline ads. The proofs are in all of them, it's a fallacy to say "ads are ALWAYS the priority". High quality papers don't even bother with tiny inline advertisers. They now use 1-2-X columns for practical reasons, for style or simply because it's nicer for their specific text format; as for any other GD layout. E.G: You won't see multi-columns in novels, they have long paragraphs while newspapers often have short ones that would look like lists in a 1-column
Answer: Small columns of text are easier to read than large ones. Imagine a newspaper sized line that stretched across an entire page. It would be very easy to skip a line. Using columns can make it easier to read, especially when the focus is on text on very large papers.
The same concept is used in brochures, which tend to be folded over paper.
Answer: In paragraph-formatted text, there will generally be about half a word of useless space in each line, and about half a line of semantically-useless empty space following each paragraph.  In text with long paragraphs, wider columns will reduce the amount of space wasted on line breaks without overly increasing the space wasted on paragraph breaks.  In text with short paragraphs, however, use of wider columns would substantially increase the amount of space wasted on paragraph breaks, in addition to calling undue visual attention to paragraphs which ended up being less than two full lines long.  Because newspaper articles often have shorter paragraphs than novels, use of shorter columns increases the amount of text that will fit in a given area, and because newspapers are very sensitive to printing cost, such considerations are more important than ease of reading.
Comment: An interesting theory, but I don't know that it holds up. While I agree the narrow columns reduce wasted 'end of paragraph' space they introduce a whole lot of extra tracking/word spacing due to word wrapping and justification. In the end, though, wasted space with text isn't a priority. The priority is getting the ads to fit. If there is too much text, that's much easier to handle via editing.
Answer: To add to Lakawak answer (who is right), yes back in the beginnings of newspapers, typesetting was the reason why newspapers were limited to only use multi-columns. It was a technological issue caused by the printing process.

As Supercat also mentioned:

Now, as for any other graphic design projects or layouts, the reason
  why newspapers or some magazines probably stick to the 2-3-4+
  multi-columns is because of their text format, they have a journalistic/news style.

If you look at the way the texts are written in newspapers, each paragraph often contains only 1-2 sentences because that's how news are reported; they are (usually) simple facts, not story-like sentences like you will find in novels.
If this text was on a 1-column layout, there would indeed be a waste of space as every "paragraph" would probably look like a list.
Not only there's a waste of space but it doesn't look good anyway (my opinion). Using multi-columns makes the sentences more compacts, creates nice blocks of paragraphs and more text can be inserted in a page. It's also more flexible since more than one article can be inserted on the same page. So layout and the style of the texts are the modern reasons why some newspapers use multi-columns, for the same reason why the bibles are often printed this way, or phone books, or dictionaries, etc.
If you look at high quality or scientific newspapers or magazine you will notice a lot of them will have no issue using a 1-2 columns instead of 4+ because the format of their text is different; a scientific, editorial or technical text is different from the journalistic style and the paragraphs may contain more than 3 sentences; unlike news that are trying to report events or facts in the simplest way possible for the biggest audience possible, these other styles usually have the freedom to explain things, use long words, no abbreviations and add their own personal style to the text as well. They also follow a different structure or methodology. Same goes for some sections of tabloids or standard newspapers, for example the "life" or "celebrity" sections; the format of the text is different, these pages are not always printed in multi-columns for that reason.
Advertising is secondary and doesn't require the use of columns in our digital era; anything can be any size and placed anywhere. Some newspapers don't even have ads within their articles but they still use the multi-column layout style. We do use some grid system in graphic design but that goes for pretty much any layout or project, it's not specific to newspapers. We simply use multi-columns when it makes sense!
As for being easier to read, it's probably true for classified ads or stock market pages, but I doubt it is for longer texts since the eye cannot follow the next sentence entirely if that sentence is split on 3-4 lines. To my knowledge (and I could be wrong), it's easier to read and understand a text when a sentence and the following sentence are entirely visible.
Answer: Newspaper columns were the result of hand held type being locked in a case. EM and EN spacing was used to fill cases so type would not fall out when the case was used.
Interesting is the column format makes a newspaper easier to read in a crowded public transportation train, bus, trolley as the paper can be folded so that the reader can select whatever column he wants without having to spread the journal out. Tabloids do not adhere to this format
Answer: The use of multiple columns is used for many reasons. Not only is it easier to read, it allows printers to draw attention to more important articles by making columns larger. It provides structure to the page and separates the articles in a way that naturally catches the eye (think rule of thirds.) It also works better for type, and easier to fit in advertisements. Imagine how boring a newspaper would look if all the articles were the width of the whole page, same font-size and all in order.
Comment: Hi Ty, welcome to GDSE and thanks for your answer. If you have any questions, please see the [help] or ping one of us in the [chat] once your reputation is sufficient (20). Keep contributing and enjoy the site!

Why do newspapers use multiple columns?


Are some beers meant to be served flat?

Question: My friend ordered a Wells Banana Bread Beer and to all three of us the beer tasted flat (carbonation-wise). She brought the beer to the bartender, who replied that that's just how that beer is. Is it true that some beers are meant to be served flat? Why? (What does it do for the taste?)
Comment: Indeed a duplicate. That's what happens when you drink and post. As @JasonMcLaughlin points out, cask conditioned beers do not force carbonation, and the Wells Banana Bread Beer is indeed a "draught seasonal cask beer."
Answer: Traditional ale styles of beer were only carbonated by using natural yeast and remaining sugars post fermentation. The ale house would "pull" pints from huge wood tanks, generally located below their taps by using traditional cask systems. CO2 was not available to breweries for most of the worlds brewing history. This led to a ale that was cellar temperature and with little to no carbonation.
Today breweries try to replicate this process by "cask conditioning" carbonating naturally their beers. So, there is no forced carbonation with CO2 and generally they do not refrigerate cask ales either.
Answer: Yes, some beers have more carbonation than others. I've yet to drink one that is 100% flat but some are pretty close. I couldn't tell you exactly what it does for any beer - the brewer simply decided that it was a good fit for this beer.

Are some beers meant to be served flat?


Authorize.net auto email receipts

Question: I am using authorize.net as a payment processor. They have automatic receipt emails that go out after a contact makes a contribution. I have disabled them from going out on my account, but they are still going out. They said it was on the Civi side and something was over-riding that setting. Does anyone know how to fix this?
Comment: To clarify: did you disable the automatic emails on your Authorize.net account or on Civi?  Also, what version of Civi and CMS are you using?
Comment: I did disable the emails on authorize.net. I am using version 4.4.3
Answer: I've never had a problem with Authorize.Net receipts going out when I've disabled the appropriate setting in Authorize.Net.  I don't have a valid Authorize.Net login to find the exact setting now, but I can confirm that I've seen the behavior you expect on multiple sites.

Authorize.net auto email receipts


Can I export my Facebook friends' contact info to Gmail?

Question: Is it possible to export my Facebook friends' contact info to Gmail?
Answer: If you a have a Yahoo account you can use that mail to import facebook contact.
Then you can import in your gmail account.
You can follow these simple steps:
IMPORT CONTATCTS TO YAHOO MAIL ACCOUNT

Login in yahoo mail
Click on contacts icon
Click on import facebook contact button
Insert your facebook credential

The contacts are now imported in yahoo.
IMPORT CONTACTS IN GMAIL
Now you can:
Use the csv file

Export yahoo imported contacts in a .csv file
Import the csv file in gmail

Or
Use the Gmail import function

Login in Gmail
Click the Settings gear in your Gmail.
Select Settings from the menu that comes up.
Go to the Accounts and Import tab.
Select what to import
Insert your credential to yahoo
Answer:
Go to http://www.friendstogmail.com and download the app.
Click the Connect with Facebook button.

Connect with Facebook button on Friends to Gmail and Google+

Click Load Friends.

Load Friends button on Friends to Gmail and Google+

You'll get the odd-looking screen below. What it does is prepare the file to be transferred to a Gmail-compatible CSV (comma-separated values) file.

Info prepared for CSV file on Friends to Gmail and Google+
Save the content in any notebook program (e.g., Notepad or TextEdit) to capture the text info.
Copying text from Friends to Gmail and Google+
When you name the file, add the ".csv" suffix.
Saving file as CSV

Open Gmail.
Click the "Gmail" link at the upper-left corner of the page and select Contacts from the drop-down.
Click Import Contacts … in the left navigation pane. The "Import contacts" dialog box will appear.

Import Contacts dialog box in Gmail

Browse to the CSV file you just created and click Import.

Gmail will then take the CSV file and import all the pertinent information you extracted from Facebook, including birthdays, city of residence, work details, etc.

Check your Google contacts once more to verify the new contacts.
Answer: A much easyer way is to use a hosted service like MemoToo and you can check out how I set it up on my blog.
If you go to http://memotoo.com and setup an account you can have your contacts synced with tons of services including:

Outlook
Google Contacts
Google Calander
Facebook (One way)
LinkedIn (One way)
Windows Live Contacts
Yahoo Contacts
Twitter
Windows Mobile
Android
Plaxo
Soocial
SheduleWorld
UNYK
Vodafone 360 (this is a realy crap service though)
And tones more

Its also ver cheap and you only need to pay £12 per year if you have more than 50 contacts. I have 2000+ and it work just fine.
Comment: just a heads up. The link to your blog leads to a 403 page.


How much time it takes before searching for tactical themes becomes a subconscious process?

Question: I would really like to have that ability.So how to achieve that?
Comment: I'm posting this answer as a comment because I suppose you really want to know *how* to achieve this ability. According to the acclaimed chess writer and teacher Jeremy Silman, '[searching for tactics] is usually done subconsciously by players 1800 and up' (How to Reassess your Chess, 4th edition). So it is less about *how long* you have been playing chess, and more about the rate at which you are improving.
Comment: Also, there is no harm in actively searching for tactics; indeed, this is often done even by very strong players when a position is particularly sharp. Over time, this conscious process becomes a subconscious one. You don't need to force anything. Just focus on improvement, and this ability will come naturally.
Answer: It is a bit like for example learning to play the piano.
At first as a beginner you look at the keys and where your fingers are going.
With increasing practice, and remember even a great piano virtuoso() will still practice every day, your thought patterns become better organised and you later play with your fingers seemingly doing the thinking for you.
() The great Artur Rubinstein practised several hours each day: he said that if he did not do this he would detect a decline in his performances.
For each player the speed that this happens will vary.
I find playing through lots of master games is most helpful.
I try to read any annotations and play through some of the variations given in the analysis.
At first I was slow and cumbersome but after a while this improved.
The secret is consistent practice.
Every day without fail set yourself the task of playing through 1 to 20 games. Little by little patterns of play will be absorbed and you will find yourself subconsciously playing better moves.
By the end of a month you will have played through 30 to 600 master games.
By the end of a year you will have played through 350 to 7000!
Create for yourself a concrete set of steps for each game.
I used to have them typed on a card and reviewed the steps before each tournament game.
After a while they become second nature.
Two phases: 1. It is your opponents move.
2. It is your move.
I can elaborate these steps if it is of interest.
Comment: Hi bretlee! There are several options to choose. 1. With real pieces and a board with printed games. Follow the annotations and some of the main variations. No need to bother in the early stages with following every long complicated variation just get the gist of what is happening in the position. Grandmaster games are excellent but depends on one's chess level of understanding. The games of untitled players are fine too. Sometimes it helps to cover the printed moves and try to guess the next move. I just play through the game and assess what is going on.
Comment: Nice answer. I'd like to add that almost every chess player has moved some processes from their conscious to their unconscious. For instance, do you still think of a knight's movement as an L-shape, or you can instantly see where a knight can move in a given position? As you progress, more and more of these processes become second nature—I like your piano analogy.
Comment: @Joe Excellent point re the Kt move, beginners struggle with this at first but with practice the move becomes second nature. When playing blitz in front of non-chessers they ask how can you think out those moves in a few seconds, I reply that it's all in the fingers, I don't think much at all it's just how my fingers move.
Comment: Okay,so i have some questions:@cousin_pete .How do you go through master games?And by master,do you mean grandmaster games?At what point do start guessing the moves of both the sides?
Comment: By that I mean things like was the game decided by a bad blunder (overlooked back rank mate) or by a series of small weaknesses (isolated doubled pawn), loss of control of a file etc etc. 2. There are many youTube videos of games with analysis and explanation of moves. 3. There are game collections online which you can freely view and play through the games. 4. There are sites which provide positions for tactical training 5. Other sites and books allow you to learn to play basic endings. You need to know all the basic checkmates, basic K+P endings, basic R+P endings.
Comment: Thanks for your help!@cousin_pete


How to use tor?

Question: So I have tor or tor browser installed on my PC I have medium security setting on but what now am I safe to search??  I'm new to this whole thing and I've got it on mobile but I don't really know what to do on PC.
Comment: Use "Safest" setting for max anonymity and safety. On a trusted site, it's safe to search with "Safer" or "Standard" setting, if necessary to see content, such as [Tor Metrics map](https://atlas.torproject.org/#map).
Answer: If you follow what The Tor Project says, you should be safe. If you're still unsure, browse around their website. If you follow their advice, you should be okay to visit any website you wish (as long as it is legal).

How to use tor?


Is being virtually nilpotent a profinite propert?

Question: If a virtually nilpotent group $G$ has  isomorphic profinite completion with another group $H$, i.e. $\hat G \cong \hat H$, does it follow that $H$ is  virtually nilpotent?
Comment: Are you asking that if $\,G\cong H\,$ as *groups*  and it $\,G\,$ is vir. nilpotent, then also $\,H\,$ is virt. nilpotent?
Comment: I edited the question and hope that it is clear now.
Answer: The following is true: If $G$ is a finitely generated virtually nilpotent group and $H$ is a residually finite group such that $G$ and $H$ have isomorphic profinite completion then $H$ is virtually nilpotent.
In fact, since $G$ is residually finite (virtually nilpotent+finitely generated implies residually finite) then $G$ can be viewed as a dense subgroup of $\widehat{G}$. If $N$ is a normal subgroup of $G$ of finite index which is nilpotent then it can be proved that the closure $\overline{N}$ of $N$ in $\widehat{G}$ is its profinite completion which is also a normal nilpotent subgroup of $\widehat{G}$ of finite index. I do not remember the details of the proof of the fact that $\overline{N}$ is nilpotent. Instead we can choose $N$ to be torsion free (easy excersise) and then the upper central series of $\overline{N}$ is just the closure of the upper central series of $N$.
Then we have proved that $\widehat{G}$ is virtually nilpotent. Now if $H$ is residually finite then $H$ can be viewed as a dense subgroup of $\widehat{H}\cong\widehat{G}$. Then $H$ is virtually nilpotent because is isomorphic to a subgroup of a virtually nilpotent group.


Why would I add my research to an online genealogy site?

Question: I have seen reference to online trees. What would be the advantages and disadvantages of me publishing my family information online?
Comment: @ACProctor - The other question was asking "When", but this one is asking "why", so I think they are different questions. Although I do agree that your answer does apply to both questions, only because "never" and "don't have to" are the same things.
Comment: Have you seen my response to a similar question here Greg: http://genealogy.stackexchange.com/a/2165/108 ? It seems to answer your question but I didn't want to simply duplicate the text.
Answer: There are many advantages and disadvantages to publishing your family history online. Listed below are a few. Your decision to publish online will depend upon your willingness to balance risk with potential gains.
Advantages:
1. Family information can be easily shared with family members, in a format they understand. This might encourage them to help add to what you know about the family, or might just be a cool way of showing off the work you've done.
2. Unknown relatives might find your family information and add to what you know, or correct misinformation.
3. Established architecture and data-entry format can allow you to easily add your information, arrange it, create reports, etc. This can be true for offline software systems also.
4. Provides a backup of your research. Whether it's a paid or free service that you choose to use, they provide server space off-site (out of your house), so if you have a home fire your research is still safe.
5. Access to data sets and scanned or transcribed records. One of the only ways to access some information (without going to the archive repository in person), might be to access what work has been done or collected by the online provider.
6. Linking your research to established and reliable sources. This can happen, if you know how to attach the source material to typed-in data and if you take the time to do so.
Disadvantages:
1. Shared information online can be copied. Therefore, if you feel your genealogy research has taken many personal hours and financial resources to accomplish, you may begrudge someone acquiring it with the click of a mouse.
2. Shared information online can be rapidly dispersed beyond what you intended. Once the cat's out of the bag, so to say.
3. As with any software, its format may limit you in ways that you don't foresee at the moment. You may find that you want to annotate a record in a certain way, but are unable with the architecture you've committed to.
4. Online storage can get hacked.
5. Online software or companies can go under, change their access policies and fees.
6. There may be limits to the number of records you can create. Once your research expands, you may need to upgrade to a different fee level.
Comment: If the software has an export feature, and exports to a common format, you could then host the data in multiple places to reduce some of the disadvantage of the provider going out of business or changing access  policies. The downside is keeping it all synced up. Great answer! +1
Answer: You have to think of what you will get out of publishing to an online family tree. So what is your objective?
I am a bit down on online trees, so bear with me a bit in this answer.
If your objective is to collaborate with known relatives on some sides of your tree, then that might be a good use of it and a valid reason. Then I would choose an online site that limits access to your tree to only approved people, Then you and your relatives can work on the tree together.
If your goal is to merge your tree to others and get others to help you fill in your blanks, then you will probably cause yourself more pain than good. Your tree will be corrupted by the masses as they merge the junk that is out there into your tree most often without any sources to verify their claims.
If your purpose is to find new relatives, then I don't suggest an online tree. I have attempted a few in the past, and the people who tend to find you are usually unrelated, or are so far off in the periphery of your family that you have very little to gain from them. There are other techniques you can use to find relatives that are better.
If you have a different purpose, please let me know in a comment. Maybe there is a good reason out there that I have missed.
Answer: Perhaps I would feel differently if I had spent the time and/or money that many on this site have in pursuit of my genealogical research, but I am personally of the opinion that research should be shared as broadly as possible. I see my research not as something that belongs to me, but that is part of a larger whole, and is most valuable when it is shared.
Some other advantages:

Putting research in a format that benefits others across space and time. For research to be the most useful, it needs to be on the web in some form or other. I want my research to be available in 20 years, and in 200 years, and I think that making it part of a large project (werelate.org and familysearch.org, in my case) gives the best chance of that happening.
By putting information online, I can help others to avoid duplicating work that I've already done. The amount of research left to be done is vast - there's no point in redoing things others have already done.
Making good research available online helps others to see what good research looks like. I've made some adjustments to my own processes just because I've learned from others' research.
Community is good - it's motivating to feel like you are part of a community that is building a resource together.

Disadvantages:

Cruddy collaborators - I definitely understand that much good research has been corrupted by sloppy research from the unwashed masses, but I would argue that this problem is solvable with technology, and is getting better already. With WeRelate, for example, the wiki format makes it very easy to simply roll back changes from someone who entered incorrect information, and the new FamilySearch Trees is also much cleaner and easier to collaborate on effectively. So, I agree that this is a potential problem, but it's getting better.
It's stuck online - I see this as a potentially large disadvantage. Syncing an online tree with offline software is far from seamless, and it can be a huge pain.
Privacy concerns - if you are planning on putting information about living people online, then you need to make sure that the information is not public. Even if it is protected, it's still less safe than on your computer, and some people may not want their information online, even if it's protected.

As you can tell, I believe that the advantages outweigh the disadvantages, and that as technology improves, the scale will tip further and further in that direction.
Comment: Agree! Well said. The 'Talk' page on WeRelate also helps with improving collaborators quality. Also note it doesn't not have to be 'all or none'. For example many lineage societes let you publish just the proven line to that particular ancestor. That particular example hits all your 'pros' and avoids all the 'cons'.
Comment: I don't feel the need to hide my research, but I do anyway, because I have seen so much falsehood and wild guesses posted.  I don't want folks copying me to contribute to that.  However, I do publish some of the info.
Comment: I disagree with #2.  I use webtrees and _easily_ edit data online.  So (1) syncing is irrelevant and (2) nothing is "stuck" unless I die without passing on the password.  I suspect some of the other packages could make the same claim.


How would one go about designing a linguistic tone in copywriting?

Question: For example, a startup might have more of a conversational or playful tone, a law office might be more serious and straight to the point. Obviously this affects the users interpretation of the site. I was wondering if there are any specific methodologies that could help in determining what type of tone might be best for the target audience?
Comment: If you are interested in how to decide on a tone, one could try simple focus group testing. If you want to learn to develop a tone, I think the best answer is "write a lot." :)
Comment: This seems to be much more suited for [writers.se] SE site. The question sounds less about user experience and design and more about how tone affects a reader and how to write for a particular audience.
Comment: For me this is well suited here. There are other questions here asking for tone like this one: http://ux.stackexchange.com/questions/63558/using-funny-error-messages-in-finance
Answer: A combination of your brand persona, the context of use of the material, and the emotional needs of your user persona can give you a sense of the appropriate tone.
Are you designing an interface used on a mobile device on an oil rig in the open ocean? Does "Ollie", your persona, need information about how to troubleshoot a safety problem?

The tone might be businesslike, maybe even brusque and without preamble, and the content might be a checklist.

Are you designing the user experience for a pregnancy test that will be distributed with Plan B? Does your persona, "Paris", need to be reassured about the accuracy of the test, and want the information while under tremendous cognitive load?

The tone might be reassuring, warm and comforting, while your content conveys factual information about efficacy rates.

Are you designing a fantasy football app meant to be used stealthily on a phone at work? Does your persona, "Frank", want to follow his team throughout the day, without anyone noticing?

The tone of your alerts might be conspiratorial, and the visual design would be subtle or might mimic the look of a business app.
Comment: well explained :)
Comment: Great answer! This is a wonderful example of how personas should be used as well.


Linux protectors: any good one out there?

Question: I know no one that works as of today (i.e., kernels not way too old) and I wonder if anybody found or knows any protector for Linux either commercial, open source, used in malware, etc...
Comment: You also may look on this thread of security.stackexchange.com : [Any comprehensive solutions for binary code protection and anti-reverse-engineering?](http://security.stackexchange.com/questions/1069/any-comprehensive-solutions-for-binary-code-protection-and-anti-reverse-engineer) It include both links to external articles and some valuable input. Bit outdated(2010-2011), but still relevant.
Comment: This is also related to [this](http://reverseengineering.stackexchange.com/questions/3184/packers-protectors-for-linux) question.
Answer: ZVrba's Phrack article on cryptexec: Next-generation runtime binary encryption is a good read and it doesn't rely on additional kernel functionality:

This article describes a
  method to control the target program that doesn't does not rely on
  any assistance from the OS kernel or processor hardware. The method
  is implemented in x86-32 GNU AS (AT&T syntax). Once the controlling
  method is devised, it is relatively trivial to include on-the-fly
  code decryption.
Answer: There is a nice article on Linux binary code protection at http://www.intel-assembler.it/portale/5/linux-binary-code-protection/linux-binary-code-protection.asp.
If your target is to protect your binary Sentinel HASP supports Linux.
As for the old ones as you mention most of them don't work anymore, elf-encrypter Shiva, Burneye etc. IF I had to guess what will be the most common in Linux malware it will be  the most common packer that's is used in windows too, UPX.
Comment: the link is dead
Answer: The majority of modern ELF binaries are protected using UPX or a variant thereof. 1,2 However, custom packers have been observed in the wild, including both UPX based- and non-UPX based-custom packers.

The simplest variation of the UPX packer used out in the wild is the 'LSD' packer, in which the string 'UPX' is changed to 'LSD'. An example of this was a XMR coin miner written in Go which targeted systems running Jenkins.

mumblehard custom protector - not based on UPX

The whole packer actually consists of about 200 assembly instructions.
  Another notable observation: system calls are made directly by using int 80h instructions. Another hint that it was written in assembly is that functions do not have the usual prologue to manage the stack. By doing system calls with interrupts, Mumblehard ELF binaries avoid any external dependency.
  Furthermore, the packer works on both Linux and BSD systems. 1

samples:

20b567084bcc6bd5ac47b2ab450bbe838ec88fc726070eb6e61032753734d233
78c19897d08e35c0e50155c87f501e20f2d1dbfd38607fc8e12711d086d52204
84dfe2ac489ba41dfb25166a983ee2d664022bbcc01058c56a1b1de82f785a43
747d985d4bd302e974474dc9ab44cb1f60cb06206f3639c5d603db94395b877b
9512cd72e901d7df95ddbcdfc42cdb16141ff155e0cb0f8321069212e0cd67a8
a5915c3060f5891242514b7899975393ef3d3cb87b33b6a767cffce4feac215f

a variant of tiny XMR mooner uses a custom packer according to the r2con 2018 presentation Unpacking the Non-Unpackable.

8a0d9c84cfb86dd1f8c9acab87738d2cb82106aee0d88396f6fa86265ff252dd
md5sum from presentation: 4f1fdacaee8e3c612c9ffbbe162042b2
Note this particular file was the subject of The "Tiny XMR mooner" Linux cryptominer malware (the sha256 sum is identical) but no mention is made in this analysis of packing or any other form of binary protection.

Tsunami with custom packer

Malshare sample
f22ffc07e0cc907f00fd6a4ecee09fe8411225badb2289c1bffa867a2a3bd863 (Virustotal)
there used to be an analysis available at pwning.fun but it looks like its been taken down.

References

Understanding Linux Malware
Modern Linux Malware Exposed
Unboxing Linux/Mumblehard (2015) - ESET


How to isolate and test time discretization order of accuracy

Question: I have a code that uses both spatial and time discretization/integration. For convergence analysis, I am wondering how one would test the order of accuracy of their ${time}$ integration scheme? I assume you would have to isolate the time discretization from the spatial discretization somehow, but I am not sure how this can be done on a discretized mesh. I suppose you could choose some really really small spatial step size such that the spatial error is less than the time error, but this seems very inelegant and complicated.
Comment: What are you considering as the truth in your analysis?
Comment: I'm taking "truth" to mean an 'exact' solution. If that's correct, then the truth is a manufactured solution (I'm using the method of manufactured solutions).
Answer: If you fix the spatial discretization, then you are solving a fixed system of ODEs. The exact solution of that system is not the same as the exact solution of the PDE, of course, but you can test convergence to it just like you would with any ODE system.
Since the exact solution is usually too complicated to work out by hand, one typically uses a highly refined (in time) solution as a substitute.
Comment: I understand. Would this method work to determine the order of accuracy of my time integration method, by comparing my numerical solution to a hypothetical exact solution, where the hypothetical exact solution is just the solution obtained using some very small $\Delta t$?
Comment: Yes, or more precisely it would work to *verify* the order of accuracy.


Do I Need to Replace Complete Rear Brake Components

Question: I inherited Mom's 1999 car with 47K on it, it was garaged for several years. I've noticed the brakes squeal intermittently dependent on how hard the brake pedal is applied. So I had a brake inspection and was told I need to replace rear pads, rotors and one caliper. The brakes look new on 3 wheels, the pad on 4th wheel is worn more. A visual inspection of all pads if measuring in sixteenth of an inch is about 0.250" thickness on 3, the 4th wheel visually looks to be about 0.1875 less. I was told, I need new rear pads; which I agree; but I was also told I needed to replace 2 rotors and the 1 caliper on the forth wheel. I'm no auto tech but I disagree with needing rotors, the pads are thick, barely worn, they're not cutting into the rotors and are nowhere near doing so, unless something seizes up. the 4th wheel is the concern because it has less meat than the others. My understanding is the piston is at fault on 1 caliper and that's the reason the 4th wheel has less meat on the pad. Do I need to replace the caliper or can it be cleaned up and and possibly lubed if its not releasing properly? The vehicle has good stopping power. Please help, I am so tired of Shops that try to take me to the cleaners.strong text
Comment: Welcome to the site. I think pictures would be extremely useful here. You can add them to the question by hitting "edit"
Comment: Having the make/model of the car in question can give you more detailed answers. Consider updating your question as such to improve your chances of success! Thanks for posting your question here ... we are here to help and would really like to see that happen :D
Comment: Zaid, thanks for the comment and for the welcome to this site. Car is a 1999 Lincoln Town, seen rain a half a dozen times, never snow, breaks were replaced prior to storage, the 4th pad after research, perhaps is related to the pin binding on Caliper. The 4th wheel has about 3/16 of pad left, the others look new. I realize pad depth varies contingent on vehicle application.This is about maintaining cars integrity and my safety; I am not quibbling over cost of a caliper. I am not in habit of being a meal ticket because someones perception tells them so. I wanted opinions.will change out fluid.
Answer: 1/16" = .0625 inches.  That is what is left on rotor #4.  There are some calipers that take more labor to clean up and rebuild than it is to buy new, labor costs more than the cost of the new.  The condition of the rotors are the determining factor for replacement:
1) Thickness of braking surface(s).  They must not be below a certain amount.
2) Grooving: if they are grooved, it is possible to have them turned, only to have them fall out of the spec from #1.
3) Color: if they are blued, glazed or have cracking, replace.  A dragging caliper will heat the rotor to the point of bluing.
4) Warpage: the disc surfaces are supposed to be flat.  If they are warped, replace. Easy to do with overheated brakes, especially if you have to stop.  The pads will keep the heat in the area that they are contacting and the rest of the rotor will cool at a different pace, and boom warped.
Knowing the procedures and specs on how to do brakes can save you money from less than reputable shops trying to take advantage.  And yes, even reputable shops sometimes take advantage too.  Looking up how to do certain things will also give you an appreciation for what the tech/mech goes through, or having done it yourself.  Search for 99 car model rear brake caliper rebuild.  There will be a forum somewhere where someone has done it and can give pointers, if nothing else, specs on what to look for and how to look for them.
Answer: This Question and Answers do an excellent job of explaining the need or not to replace rotors.
Rotors are relatively inexpensive and if you want to ensure you brakes are effective then resurfacing the rotors or procuring new ones is a good idea.  It's not necessarily about grooves in the rotors or not.
The caliper rebuild could be a few hours of flat rate labor and it's probably cheaper for you to buy the single caliper than rebuild it.
Comment: From having a loose nut behind the steering wheel(me) and laziness, I learned the hard way about caring for the brakes.  The few times I was not able to do the job myself, and ignore the rotor condition(loose nut remember?), some of the rotors were badly grooved. They were able to justify, correctly imho, to me, that it would be cheaper to just replace the rotors than to resurface them only to have to replace them due to falling out of spec and still have to pay the labor for the resurfacing.  Grooving is hard to measure accurately the depth and width of the rotors.


How to find systems with vulnerability which may later become agent for DDoS?

Question: How to determine the  systems with vulnerability, which scanning tool is best.  The system should be identified so that it can be used as agent for DDoS. In a test bed environment I want to check this. Can anyone help?
Answer: Not directly related to your question but a idea that may become handy somewhere in the future is the concept of enabling netflow in your network infrastructure.
Once your network devices start reporting network flows to a netflow collector you can relatively easy detect which machines are being used as part of a DDoS campaign. Those that shows a spike in the number of flows per second may very well be the ones that are already compromised and used as a DDoS tool to disable a target (netflow has many other uses in security).
There are many other "traffic engineering" techniques that are useful to detect this kind of behavior in an enterprise network (and many others in a service provider environment).
For example through traffic engineering (routing) you could "attract" all the traffic destined to the IP address space (i.e. RFC1918/RFC5735) that your organization is not using into a device that is commonly referred to as the "sinkhole". You should normally never see traffic in the sinkhole, but if you do, it may be signaling the presence of compromised machines in your infrastructure that are generating traffic to IP addresses that are not valid inside your organization. Because you are "attracting" this traffic, they end at the sinkhole. This behavior may also be the result of infected machines scanning your organization searching for victims to further spread, etc.
Answer: Any system can become compromised and be used for DDoS.   To remotely scan a system to see if it is vulnerable to attack you can use OpenVAS.  Compromised machines are also used to send spam,  many ip addresses on a Realtime Black List are also members of a botnet which are often used for DDoS.
Answer: A combined use of nmap and metasploit can help you detect a vulnerability and launch an attack in a test environment.
http://nmap.org
http://www.metasploit.com
Answer: Try OpenVas
The URL is
http://www.openvas.org/


When is a high order method useful for computational fluid dynamics simulations?

Question: Many numerical approaches to CFD can be extended to arbitrarily high order (for instance, discontinuous Galerkin methods, WENO methods, spectral differencing, etc.).  How should I choose an appropriate order of accuracy for a given problem?
Answer: In practice, most people stick to relatively low orders, usually first or second order.  This view is often challenged by more theoretical researchers that believe in more accurate answers .  The rate of convergence for simple smooth problems is well documented, for example see Bill Mitchell's comparison of hp adaptivity.
While for theoretical works it is nice to see what the convergence rate are, for more application oriented among us this concern is balanced with constitutive laws, necessary precision, and code complexity.  It doesn't make much since in many porous media problems that solve over a highly discontinuous media to have high order methods,  the numerical error will dominate the discretization errors.  The same concern applies for problems that include a large number of degrees of freedom.  Since low-order implicit methods have a smaller bandwidth and often a better conditioning, the high order method becomes too costly to solve.  Finally the code complexity of switching orders and types of polynomials is usually too much for the graduate students running the application codes.
Comment: You may want to discuss wave propagation problems where low numerical diffusion is important, seismic imaging (SPECFEM), DNS (spectral and high order FD), LES (Nek5000 spectral element), and the heterogenous wave problems that `ketch` has been using WENO for.
Answer: Guidelines: High-order methods for problem where solution is expected to be smooth and otherwise low-order methods and/or methods which can handle discontinuities in solutions. In cases where high-order methods can be exploited there can be significant saving in computational effort measured in terms CPU time as a result of high convergence rate. For elliptic problems which require solution of linear systems, high-order methods leads to less sparse operators and this have to be compensated by faster convergence rate. For time-dependent problems, if high-order methods can be exploited faster convergence rate and more accuracy can be achieved and for long integration times high-order methods are superior in terms of both accuracy and computational effort due to low numerical dispersion and dissipation errors.
Answer: Always implement at least two distinct orders. On a representative problem, solve once using each order. Compare the two on a grid fine enough to be converged at the lower order. Ensure your two answers are reasonably close which gives some indication that the numerical behavior of the lower order scheme hasn't overwhelmingly damaged the solution. If it has, toss the lower order scheme and start over.
Assuming you didn't have to start over, coarsen the grid for the higher order as much as possible while still maintaining a reasonably accurate solution as measured by the specific quantity of interest you want. Compare the computational cost for the lower order on the finer grid to that of the higher order on the coarser grid.
Choose whichever is more operationally advantageous. Document the process for naysayers and so that you can repeat it when the representative problem or quantity of interest changes.
Answer: Higher order methods can be used e.g. to solve the level set equation when using it to describe a two phase fluid flow within a Finite Volume Method framework. In this case, the WENO and ENO schemes are used to advect the level set function and a re-initialisation step is used to maintain it as a distance function from the fluid interface.
Check this out:  http://ftp.cc.ac.cn/lcfd/WENO_mem.html
Basically, they are used in CFD simulations when dealing with discontinuities in the flow.


A drop of milk gets into the chicken soup, can one still eat the soup?

Question: I think it has something to do with the 1/60 rule but I don't know what that is.
Comment: How is this asking for a psak any more than any other [tag:halacha] question?
Comment: Welcome to MiYodeya Yehuda. Since MY is different from other sites you might be used to, see [here](https://judaism.meta.stackexchange.com/a/3887/11501) for a guide which might help understand the site. One of the things we don't do is answer specific requests for halachic decisions as they depend a lot on the context (as you can see from the comments above). As such this question might be closed but don't let this discourage yourself from browsing and learning with us. Hope to see you around!
Comment: @ba Before Danny's edit, this was written in the first person, which gave the implication that they were asking for themselves.
Comment: For practical advice on halacha, please consult your local Orthodox rabbi.
Comment: related: [How is batel beshishim verified practically?](https://judaism.stackexchange.com/q/94038/11501)
Answer: Let me offer a practical answer to what is a deceptively simple question

If there is only hot soup and no meat, or if there is meat but the milk fell in the soup: if the volume of soup (including any meat) is 60x greater than the volume of milk which fell, the dish is kosher (SA YD 92:2) and you should stir the soup (MT Ma'achalot Asurot 9:10, Kaf HaHayim 92:8). If the soup is not 60x the volume of milk then the dish is not kosher and the pot needs to be kashered.
If there is chicken in gravy and the milk fell on a piece of chicken: if the volume of meat is 60x greater than the volume of milk which fell, the dish is kosher but one should remove a little less than an inch of meat (ca. 2cm.) around the area where the milk fell. If there is not 60x then the dish is not kosher and the pot needs to be kashered
If the milk fell on a piece of chicken protruding from the soup: this becomes really complicated: you have to ask a rav

In all cases one should not add more soup to make up the 1:60 ratio.
This is for Ashkenazim following the Rema that we don't ask a non-Jew to taste and go according to bitul be shishim (SA YD 98:1).
In all cases, you should ask a rav as small changes in the starting situation can have big impact on the halacha.
Sources: Eretz Hemda's Living the halachic process vol. 1 p. 240; R Yossef Loria's fundamentals of kashrut p. 386; Star-K on bitul b'shishim
Answer: The questioner is correct.
Shulcha aruch Yore dea 98,1

איסור שנתערב בהיתר מין בשאינו מינו כגון חלב שנתערב בבשר יטעמנו גוי אם אומר שאין בו טעם חלב או שאומר שיש בו טעם אלא שהוא פגום מותר והוא שלא יהא סופו להשביח וצריך שלא ידע שסומכין עליו ואם אין שם גוי לטועמו משערינן בס' וכן אם הוא מין במינו כיון דליכא למיקם אטעמא משערים בס'.
  Something forbidden to eat that got mixed into food which was permitted to eat like milk and meat (which is forbidden together) should be tasted by a gentile and if he can't taste the milk it is permitted. Alternatively if it has a rotten taste it is permitted to eat this mixture as long as it won't end up tasting good together in the future. This gentile has to be reliable and if such a person not available one measures if the milk is a ratio of 1:60 to the meat it is pemitted.

Rema Orach chaim 98,1

(ואין נוהגים עכשיו לסמוך אגוי ומשערינן הכל בס)
  we don't rely o a gentile in our commuities rather we always measure a ratio of 1:60 to permit the milk/forbidden substance.

This also applies to soup with meat (when the meat is a 60th or more of the volume of the soup)even though its not pure meat because the soup becomes a neveila (forbidden like the meat "chanan") in matters of milk mixing with meat Shulchan Aruch 99,3: (note rema says Chanan with every forbidden substance that mixes with permitted substance)

בשאר איסורים חוץ מבשר בחלב חתיכה הבלועה מאיסור מצטרפת לבטל האיסור.

And the rema Yore dea 92,4 says that liquid becomes a neveila in a case of milk and meat mix together.
Coclusion: Ashkenazim follow the Rema who requires a ratio of 1:60 of milk against meaty soup, most Sefardim follow the Shulchan aruch and get a expert trustworthy gentile to taste the soup but if unavailable also require a ratio of 1:60 of milk against meaty soup  .
Note: this is only whe the milk falls inadvertently into the meat soup but if one pours it in on purpose the mixture is forbidden see S.A Y.D 99,5.
Comment: The one about טעימת ישראל. If the Sefardi tastes it and doesn't taste milk, the Ashkenzi can trust him and eat it even if there isn't shishim. Point is Ashkenazim can also rely on tasting, everyone does, it's just a matter of who you trust.
Comment: What about the Shach?
Comment: are you reffering to a specific shach i'd be interested where it is @DoubleAA
Comment: does't the shach also say that relynig on people who are not expert tasters (not knowing what milk ad meat together taste like) should not be done lechatchila?
Answer: If the amount of milk that fell in was less than 1/60 of the amount of soup than the soup may be eaten.
Comment: Source(s) please...
Comment: More precisely: if the milk didn't improve the flavor of the soup then it may be eaten. If you aren't sure or can't check, then you can generally assume that "if the amount of milk that fell in was less than 1/60 of the amount of soup than the soup may be eaten."
Comment: @DoubleAA Are you alluding to a possibility that, in order for the soup to be kosher, the milk might need to be less than one 60th of the soup, or do you mean that sometimes it may be even more than 1/60 and still be kosher?
Comment: Both. [15charac]
Comment: Batel biShishim is much more complicated than "1/60." As DoubleAA notes, you have to account for nosein ta'am lifegam/lishevach. I recommend looking at the halachos of ta'aroves in Yoreh De'ah.


Did Prophet Mohammad (peace be upon him) see Allah (Swt) on Miraj?

Question: Did Our Prophet Mohammad (peace be upon Him) see Allah (Swt) with his eyes on Miraj?
Answer: First of all it ought to be expressed that your question is counted as a FAQ, since it is considered as the question of many people. God bless you for asking such important question. As you asked

Did prophet Mohammad peace be upon him see Allah Swt on Miraj

Concise answer:
As the most related important issue, we should notice that Allah is not body or material. And in truth it is not possible to see Him by vision. Because seeing (by eyes) is related to the material.
On the other hand, seeing which is mentioned in some traditions (hadiths), is related to hearty or sincere seeing, and likewise seeing (or feeling) by the eye of the heart (it is an expression).
E.g. look at the following sentence example:
I saw how much he was talking to his mother in a polite manner.

Conclusion:
Talking is not see-able, but here it said "I saw how much he was talking…" then it means understanding or hearing or even seeing by the eye of the heart as a kind of feeling. Consequently it can be inferred from the mentioned hadiths that perhaps Prophet Muhammad saw (comprehended or felt) Allah by seeing many facts, wonderful things and signs and so on.

References:

porseman.org
rasoolnoor.com
www.mashreghnews.ir
Comment: This answer lacks references. Please post them to enhance it.
Comment: Thanks a lot brother. Now i can also refer this information to others so that they understand.
Answer: It is clear from the Books that the believers will meet Allah hereafter. The only issue that remains is whether it happened in the case of Prophet (s.a.w.s) in this world. It is clear from the descriptions that Prophet (sws) had seen Allah appropriate to  His Majesty. "How" is it, cannot be explained in words.
 Narrated Jarir r:
Allah's Messenger (ﷺ) came out to us on the night of the full moon and said, "You will see your Lord on the Day of Resurrection as you see this (full moon) and you will have no difficulty in seeing Him." Saheehul Bhukari-7436.
In the case of Musa a.s. please analyse what Allah said:
"And when Moses arrived at Our appointed time and his Lord spoke to him, he said, "My Lord, show me [Yourself] that I may look at You." [ Allah ] said, "You will not see Me, but look at the mountain; if it should remain in place, then you will see Me." But when his Lord appeared to the mountain, He rendered it level, and Moses fell unconscious. And when he awoke, he said, "Exalted are You! I have repented to You, and I am the first of the believers." - Allah (swt) did not say He can never be seen. The impossibility of seeing from this earth/world only stated. In Mirage, the venue is different. (The Holy Quran 7:143)
Comment: Your example from the Holy Qur'an is for me evidence that Allah swt can not be seen by the means of the eyes.


Are same-gender classrooms better for girls, or mixed-gender classrooms better for boys?

Question: I've heard that girls learn better in an all-girl classroom setting, but that boys learn better in a mixed boy/girl classroom composition. Is there any statistical evidence that this lends merit to this argument? What factors were measured, and what is the psychological explanation behind the findings?
Comment: Boys in same-sex settings do not feel the need for aggressive and showy behavior to impress girls, and girls do not feel the need to behave cute and stupid. That's why in some cases *both* genders do better. Single-gender classes is a bad idea for other reasons though, it's better to have one class and sometimes split it. However I can't find the research that is the source for these statements, so it's not an answer but a comment.
Comment: And "ratio"? Wouldn't "mixed vs same-gender education" be a better title? It's not like 35% girls is gonna make a difference vs 45% girls. :)
Comment: @Lennart - Good point, I changed the title..
Comment: One day, I hope we will see classes with kids that learn the same way. Some kid can sit down for hours and some must move and touch. It's not about gender, but personality. These personality trait tend to be generalized by gender.
Answer: The answer depends a lot on the culture the children are raised in.  For example, when working with children raised in a culture where strict gender roles are the norm, and boys and girls aren't normally allowed to socialize with one another, I found that children performed considerably better when segregated by sex.  Boys and girls just weren't sure how to act one another, and they were wasting processor cycles on that instead of their schoolwork.
On the other hand, when working with children raised in a culture where sex roles were not so divided (boys and girls might favor different toys, but they socialized freely and didn't see one another as foreign and confusing), I found no difference in the performance of same-sex and mixed classroom in aggregate.
However this isn't great anecdotal evidence, because I never experienced a case where classrooms segregated by sex were taught the same material the same way.  In every case, girls' classes centered around language skills and promoted conservative strategies, while boys' classes emphasized math and science and promoted risk-taking.  This could be interpreted to mean that girls and boys raised in strict sex roles have different educational needs, or it could be interpreted to mean that girls and boys raised that way appear to perform better when the subjects and strategies stereotypically associated with the other gender (and bearing a stigma for their own gender) are de-emphasized.
As a side note, though the question only addressed educational performance, I felt the need to address the impact on socialization between the sexes as well. In both settings, children educated in same-sex settings had trouble working with the opposite sex in a professional setting as adults (some got over it with experience, some didn't, and it was far more pronounced in cultures with strict sex roles).  Additionally, teenagers who spent their entire childhoods in same-sex education tended to have more stereotypical views of the opposite sex: this was adaptive in a society where those stereotypes were the only permitted behavior, it was like learning a script you would have to perform later, but was maladaptive in a more varied society where both boys' and girls' real behavior was more individual.
Comment: Good answer. If you can cite references or be more specific about where your findings come from, how the study was conducted, and what the sample size was (particularly in the 4th paragraph) I'll vote you up.
Comment: @Javid I'm sorry if I was unclear: these are not the results of a formal study, but of my observations working in several different schools.  The studies I have seen fall equally often on either side -- in favor of segregation or in favor of mixing -- in my opinion, because to my knowledge none of them look at the cultural aspect.
Comment: Interesting to see this come up today, because I read an article just this week about how "separate but equal" classrooms may not be such a good idea. If I can find it again I'll post a link.
Comment: +1 For the fourth paragraph! I was raised in a conservative society and went to a all-girls school. I found it real hard to interact with boys/men when I went on for course work and then work in Engineering. There was nothing malicious from the boys, its just the awkwardness of spending all day in a male-dominated environment. Fortunately, my family pushed me to go for advanced degree, otherwise, who knows, I might have dropped out at undergratuate level.
Answer: Most of my queries on Google Scholar returned results for a very specific age group (grade school, college, etc), subject (science, computer skills, etc), or learning approaches/settings (in-class instruction, small group projects, etc). Finding a more broadly-scoped experiment or observational study on this topic would require quite a bit of digging, and perhaps some help from a subject librarian at your local library or college/university.
HedgeMage mentioned the distinction between academic learning and social learning, and I would like to underscore this distinction. The answer to your question will likely be different if you only care about academic performance vs if you only care about social development vs if you care about overall performance/development. Complicating the matter further, both academic performance and social development can be broken down into multiple categories (exposure to facts/ideas, development of important technical skills, ability to work with others, respect for other people, respect for other cultures, etc). And there are probably other aspects of the educational process that I'm not even considering now!
This is probably why it will be difficult to find any statistical evidence for a broadly-scoped study of this topic, and why so many of the studies focus on specifics. It might be worth looking at a few different studies that approach the topic from different angles.
Answer: The earlier answers are way too complicated for a parent in the U.S. seeking practical advice.  So here goes:
I taught in mixed, all-girls, and all-boys high schools, and substituted in middle schools, and I can say categorically, at least at the middle and high-school level, that for the vast majority of students, the best classroom is the one with the highest possible number of girls.
For boys in virtually any subculture in the U.S., the presence of girls is a moderating/civilizing influence, making the classroom easier to manage and thus to learn in.
For girls, the absence of boys increases civility with the aforementioned benefits, with the added benefit that they are dramatically more likely to get the teacher's attention and high expectations.
It's really that simple.  I have little doubt that my observations apply equally to college undergrad.  I'm less sure about elementary.
Full disclosure: not atypically for public school teachers, who send their own children to private schools at twice the rate of the general population (think about that before you send your precious little one to public school, please), I spend a large percentage of my after-tax income to send my daughter to an all-girls school.  I believe she's worth it.
Answer: I went to an all-boys elementary school and a mixed high school, so I have very personal experience with both.
IMO, the main downside of an all-boys school is that it makes you unfamiliar with the ways of the female gender. If you're a male geek (like myself), going to an all-boys school doesn't exactly help make you feel less socially awkard among girls... quite the contrary!
On the other hand, being in the same class with peers of the opposite gender can be very distracting, especially during puberty. Also, boys and girls tend to learn very differently and mature at a different rate. This can complicate matters significantly when putting boys and girls in the same class.
So what is better? If your kid has siblings of the opposite gender and feels comfortable around peers of the opposite gender, I would recommend same-gender classroom. However, if your kid has no siblings of the opposite gender and/or is known to feel uncomfortable around peers of the opposite gender, it may be better to send him/her to a mixed classroom.
In the end, I don't believe there's a "one-size-fits-all" solution.


How do I get the ink flowing in new gel pens?

Question: My new 72 pack of gel pens are 75% unusable due to the ink in the gel pens being stuck at the wrong end of the pen and no ink near the tip? How can I get the ink flowing down the tube to the point? I've had them point down for 5 days now only 50% of the ink in the gel pens has actually traveled down to the tips...
Comment: I've never experienced this problem, but I would have thought it's worth a try to heat them gently to see if the gel temporarily loses some of its viscosity and allows gravity to do what it does best...?
Comment: Related, possibly duplicate - https://lifehacks.stackexchange.com/q/13465/6973
Comment: Some pens have a tiny plastic or wax covering to the tip to prevent accidental leakage. Don't forget to check for this and remove it if present. Sometimes it takes more than just scribbling. I've had to use my fingernail to break off the glob before.
Comment: That number of failures suggests you bought/got both OEM factory seconds due to the points being incorrectly inserted (end-for-end) during assembly. It also sounds as if 'seconds' got mixed with some good pens and it was cheaper to sell them 'as-is' rather than sort, count, re-package. Can you pull the point and re-insert for those that are backwards? Can you complain to the seller for a partial (substantial) refund? Good luck
Answer: You can easily utilize centrifugal force to move the ink to where you need it.
Grap the pen securely at the bottom end, letting the tip extend from your hand. Now quickly rotate your hand and move the tip of the pen in an arc around it. The centrifugal force will push the ink from the inner parts of the arc (the bottom of the pen) to the outermost part (the tip of the pen).
Start with only a few shakes. Depending on how liquid the ink is, you may shake some ink out of the tip, creating a real mess inside the pens cap.
A similar technique is used to "shake down" old-fashioned thermometers.

Image Source
Answer: Heating the ink cartridges will do it easily. Remove the cartridge and hold it under a stream of hot water. If it has dried in the nib, hold just the metallic tip in the flame of a  lighter for 1 to 3 seconds. Either singlely or combined these techniques should restore an old ink pen to functionality. The nib-in-flame method can be used to squeeze out a little more from a dead pen.


Why can I only move my Queen vertically?

Question: I'm playing a game on chess.com and I want to move my Queen to h7. The website won't let me move it there. I tried moving it to other places but the only way I will let me move it is vertically. Is there a rule or something I'm missing, or is this a bug in the game?
Comment: You're pinned, you can't move it. Your position is hopeless, it's game over.
Answer: The Rook on e8 is pinning your Queen against the King. You cannot expose your King to check.
Answer: As pointed out, your Queen is in what is called an "absolute" pin.  It absolutely cannot move off of the file, in this case the "e" file because the black Rook is controlling the squares on that file up to the point of your King.  It appears that your only choices in the position you are in, if it is white to move, would be 1. Qxe8+ expecting the response 1....Bxe8 or 1...fxe4.  Also you could move 1.Be3 (to block the Rook's pin) expecting the response to be either 1....Rxe4 allowing you to recapture 2. Bxe4 or less likely 1...dxe3 which would leave the King un pinned but the Queen still under attack.
A second form of pin is "relative" pin where the piece behind the directly attacked piece is something other than a King.  In other words, something you value but not something that would create an illegal move if it were moved.  Imagine in the setting above that the White Queen were a Bishop and the White king were a Queen.  You would not want to move the Bishop to expose the Queen which is much more valued.  The Bishop is therefore in a relative pin (to the queen).
Hope this helps.