What is the meaning of "stopped down"?

Question: Was reading this answer (emphasis mine):

It also tells us that the lens was stopped down, as if it were wide open there would be no corners to cause diffraction, regardless of the number of aperture blades.

What does "stopped down" mean?
Comment: It's amazing how many terms I use without even thinking that to a layman would sound like nonsense!
Comment: @Matt: Hey, I work in software development. I'm used to "strange terms" on a regular basis. (Though usually *our* strange terms are TLAs, ETLAs, or EETLAs) (Three letter acronym, extended three letter acronym, expanded extended three letter acronym)....
Comment: You mean, like Four Letter TLAs?? ;-)
Comment: @ysap: Yup. TLA is a TLA. ETLA is an ETLA. EETLA is an EETLA :)
Answer: This picture shows a lens at different apertures.  I used a manual focus lens (a Soviet-built 50mm f/1.9) because having aperture controls on the lens itself made it easier to take pictures of the lens at different apertures.

In the top third, the lens is wide open, or at its maximum (widest) aperture (lowest f-stop value), in this case f/1.9.  The aperture blades are fully withdrawn into the lens housing and do not restrict any light from passing through the lens.
In the bottom right, the lens has been stopped down about one stop to f/2.8.  It is no longer at its widest aperture: you can see the aperture blades have physically extended into the lens opening slightly, to restrict some of the light coming through the lens (if I understand correctly, one stop cuts the light coming through the lens by half; this lens has been stopped down by just over one stop (from f/1.9 to f/2.8; normally one stop would be from f/2.0 to f/2.8) so the aperture blades should actually be covering just a little more than half of the area of the lens).
In the bottom left, the lens has been stopped all the way down to f/16, it's smallest aperture (and highest f-stop value).  This lens has six aperture blades; in this portion of the picture you can see three of them meeting.

(I apologize for the different exposure of the bottom-left photo.  I was shooting in Av, not Manual; perhaps the different reflection of light from the fully-stopped-down lens convinced my camera to up its exposure by 1/3 stop.  I'll leave this as a reminder to readers to shoot in manual whenever you're combining multiple photos)
Here is a picture of the lens at f/16 to see what it looks fully stopped down:
Answer: It means the diameter of the aperture stop (a physical object in the centre of the lens which literally stops light to increase depth of field and decrease exposure) was reduced (by the photographer either via the camera body or directly on the lens) some amount from its widest setting.
See:

Where does the term "f-stop" come from?
What does f-stop mean?
Comment: @Billy ONeal — just trying to help. I didn't think it warranted a comment. :)
Comment: @mattdm: Yay, pedantry!
Comment: @mattdm: Lol -- only reason I mentioned it is that you [proved me wrong](http://english.stackexchange.com/questions/13148/why-is-there-a-distinction-between-its-and-its) :)
Comment: Doh! I'm normally good at not using "it's" for a possessive! I really don't mind minor corrections like this, anything that makes the site easier to read and use...
Comment: I'm sorry for switching the accepted answer on ya -- but the pictures from drewbenn really illustrate the point well.
Answer: "Stopped Down" simply means "with a small aperture". The aperture is expressed as a fraction, for example, f/8 or f/2 -- f/8 (the aperture is physically an eighth as wide as the focal length) is smaller than f/2 (the aperture is half as wide as the focal length)
Comment: Depends on what you mean by "has more to do". You control the stopping down with the camera (at least on modern cameras/lenses), but the action primarily effects the lens.
Comment: In my Pentax Auto110, the aperture stop is part of the camera body, not the tiny interchangeable lenses. (The same iris also serves as the shutter!)
Comment: Okay, so this has more to do with the camera than with the lens?
Answer: It does not mean "with a small aperture"; it means that the lens is at a smaller aperture than it is capable of. f/1.8 for example is not a small aperture; a 50 mm f/1.8 would be wide open at f/1.8 but a 50mm f/1.2 would be "stopped down" at f/1.8. Conversely, f/5.6 is really a rather small aperture, but an 18-200 f/3.5-5.6 would be wide open at 200 mm f/5.6; a 70-200 f/2.8 would be stopped down by two full stops at the same setting.
(Ah, crap. Was meant as a comment to another answer. But it works as an answer in its own right too so never mind...)
Answer: If you have a typical lens which starts with Aperture of F3.5, then any increase in F stop, say to F4.5, would mean you are stopping down the lens.
Answer: Confusion continues to reign about Fstops and the terminology 'stopping down'
It is a factor when listening or veiwing Youtube videos and the contributor says "I stopped down the lens" without giving an explanation for those that don't know what that means.. It literally means 'increasing the number on the Fstop dial/indicator upwards by number e.g.: fstop 2.8 to Stop 3.4...on upwards. Of course increasing/"stopping down" also decreases the the size of the diameter of the aperture which results in reducing the amount of light reaching the sensor, that in turn means your getting less light because your shutter speed will be faster. So you need to adjust your shutter speed to a slower period to allow and compensate for more light needed as you 'stop down' then and even further. ISO can  be adjusted too..but can result in higher 'noise' or grainer image quality.

What is the meaning of "stopped down"?


Bayesian networks tutorial

Question: For a beginner, which is the best book to start with for studying Bayesian Networks?
Answer: I would recommend "Probabilistic Graphical Models" by Daphne Koller and Nir Friedman. Its an excellent starter-to-intermediate handbook on both directed (Bayesian Networks) and undirected (Markov Networks) graphical models. The examples given are elaborate and easy to understand.
Comment: Koller is/was teaching a class on probabilistic graphical model on Coursera: https://www.coursera.org/course/pgm
Answer: A good book on general machine learning is 1. But it is quite light on BN. I haven't read  [2] but I have read [3] by him which is good (so, [2] is likely to be good as recommended by dwf). I would not recommend Pearl's book at all unless you are doing your Ph.D.!
However, I actually would recommend the online tutorial "A Brief Introduction to Graphical Models and Bayesian Networks" by Kevin Murphy [4]. The best way to learn BN is to read this, download his Matlab toolbox [5] and build your own BN in ten minutes.

Pattern classification by Duda/Hart/Stork
Pattern Recognition and Machine Learning by Chris Bishop
Neural Networks for Pattern Recognition by Chris Bishop
http://www.cs.ubc.ca/~murphyk/Bayes/bnintro.html
Bayes Net Toolbox for Matlab
Answer: You should check for AI (Artificial Intelligence) books. I've learn about Bayesian  in Artificial Intelligence "A modern approach".
Comment: So did I. It was an interesting read.
Answer: This online book has been extremely helpful for me in all aspects of machine learning, including Bayesian inference:
http://www.inference.phy.cam.ac.uk/mackay/itila/book.html
Granted you are familiar with basic probability theory, its a great resource.
Answer: All the books mentioned so far are pretty good ones. Pearl's is generally regarded as being a bit hard to follow, it's also quite expensive, but if you can manage it, all the power to you.
I'd really really recommend you check out Chris Bishop's book, Pattern Recognition and Machine Learning. I think it's far and away the best treatment you're going to get of graphical models in a textbook, at least until Michael Jordan finishes and publishes his book on the subject.
Comment: plus one, especially Bishop's Book (but requires that you read math well)
Answer: The best professors in this fields are by my point of view these 2 guys:link text Ng. Andrew and link text Prof. Pallab Dasgupta.
I have been watching all their tutorials on BBN and they were very usefull.Just follow the links and you will find more AI lectures with this 2 interesting guys.
Have fun learning with them,
Mike
Comment: both led to 404
Answer: Pearl's 1988 Probabilistic Reasoning in Intelligent Systems is the one of the most cited works on Bayesian Networks.  I found it quite clear. That said, a lot has been done in the field since 1988. It would be wise to supplement this book with more recent works.
Answer: Mitchell's Machine Learning is an extremely important primer in the area of AI.  It covers Bayesian Networks, devoting, as I recall, an entire chapter to it.
I'd also check out Weka's Bayesian Network class to understand a practical implementation.  If you don't know about Weka, check it out here: http://www.cs.waikato.ac.nz/ml/weka/

Bayesian networks tutorial


What security risks are there with employees using Dropbox?

Question: Are there any particular security concerns to keep in mind with company-wide use of Dropbox file sharing / versioning / backing up, and are there specific options or settings that would be recommended to limit the risk?
Comment: Here's a detailed description of some core security and legal issues with Dropbox for corporate and private use: http://blog.5ttt.org/dropbox
Answer: It depends on your business and your level of paranoia.  It's much safer, albeit more expensive, to issue laptops with a VPN connection.
Real quick...
Some Risks:

Former employees potentially have access to business data after employment has been terminated.  You as the business MUST be in control of the accounts if you don't want some disgruntled employee to have access to things after getting fired...
These services would bypass any automated document retention mechanisms you have in place which adds another area for you to manually cover for document retention

Recommendations:

Make sure you can generate your own encryption key(s) for storing the data and that the key(s) are not shared with the service provider
Make sure your data is encrypted BEFORE it gets sent to the service's repository
If you are going to let individuals have their own account then have a single point of contact for your company.  Coordinate all accounts through this person (or a couple of people as proxies).  Or make sure that the provider supports business accounts that you can somehow group employees under.
Comment: The point about not controlling the accounts of ex-employees was helpful. We will add unsharing of folders as part of any termination plan.
Comment: It also poses a problem for any EU business, as there's obvious risks for personal data to end up in uncontrolled environments. The same goes for any US business who wants to keep a Safe Harbor certification (so they can process EU personal data).
Answer: I would tread very carefully here.  Dropbox enables an extension to another computer's hard drive.
That extension is worse than a USB key in the sense that infections on one PC can get onto all the other PCs using that share much more easily than with a USB key.  Virus/trojan/bot writers don't target dropbox (yet) but if they decide to, then you've got a virtual unlocked door from a company controlled PC on a secure network to an unsecure computer on an unsecure network.  As is, using normal operations, one can't just go through that door and look at other things on the computer - only items within the dropbox can be seen, and new items can only be created in that area, but that's assuming that the dropbox application itself can't be compromised.
Further, Dropbox claims a great deal of security, but what is actually provable to you?  It's possible someone can sneak in that window remotely from a completely different PC and attempt to put infected documents and programs onto the work PC.
There is obviously a protocol dropbox itself uses to communicate with its clients - is it encrypted?  Is it immune to buffer overflows?  Man in the middle attacks?  Sniffing?  Replay attacks?  Is it possible to, using the standard protocol, place files inside or even outside the standard dropbox area?  If the protocol has a buffer overflow, is it possible to compromise it in a way to allow full access to the machine?  Network shares on the machine?
I don't think the risk is very high, but the damage done can be extensive, so it's something that has to be carefully thought out.
-Adam
Comment: Internally Dropbox uses rsync thru a Python executable. Although I'd hazzard a guess that the protocol used isn't standard.
Answer: Paranoia????
Dude.. Step away from the network.. SLOWLY.. With your hands away from the Keyboard.. DO IT NOW!!!
File share cloud based "consumer" solutions like Dropbox, are not meant for Business or Corporations. Microsoft said it best with Skydrive when they came out and said, that these types of products are not, and should not be used for Business purposes.
There are thousands of reasons why not that outweigh the reasons why one should.
Biggest LEGAL reason outside of the security risks (And the Terms of Use which specify that 3rd parties can have access to confidential files hence nothing confidential should ever be stored on such a service that is consumer based.. EVER..) is the fact with a service such as Dropbox, well. Let me ask this.. Where are those files stored? Where are those servers located? You can rest assured, with the lowest bidder, call in something called Data Export Rules and Laws...
Should you have a single tiny file the "United States Government may deem as a risk or potential risk to U.S. security" (Could be something as small as electrical layout to a public gathering place, school, gym, passwords or a username to something like a Cisco account where you can download export restricted software, etc)  up to classified documents, you are in violation of that law. You go to jail, you do not pass go.. I believe now, that is handled by FTC and Homeland Security..
The DB terms of use specify (basically) that if its installed on a business PC, (Dropbox assumes that person because the person installing in on the business PC guarantees they are by clicking through the TOU) that the "authorized" individual is doing so FOR THE ENTIRE COMPANY.. Period... (First section ion Dropbox.com/terms)
What stops me from using this outside of my server and work environment is simply ethics... You have a consumer product like Skydrive that in big letters says "No Business.. Don't! because they do not want to risk customer's data on a business level because they KNOW it is a risk! And then Flippin Dropbox who uses legal words in their contracts such as the word "stuff", who patty cakes the entire "security thing" and acts like its no big deal (would you want to lose profit and shares that valuable? Probably not...)....
It is a big deal.. The more security groups beg you and I to follow simple practices, the more big comps like dropbox come out and for money.. for profit, act like its no big deal...
What if your business stored a tiny piece of a single credit card number and a name and expiration date?  Now say the PC the dropbox client was installed upon was uhmm "gotten into.." through a Dropbox security breech... Following me? Visa/Amex etc.. the ginormous bank companies WITH government support (because Payment Card Industry (PCI) Standards says so.. that's who...) WILL fine you.. get this... you may want to sit down.. a staggering $500,000.00 PER INCIDENT...  It is enough to put a small or medium business out of the business they are in....
the ONLY way to get around it, is to locally encrypt that data using a PCI certified encryption product, BEFORE it goes to dropbox, purchasing licensing for all your remote devices, downloading the file you need, and de-encrypting it before you can use it.. (Nope don't sound like it aint no funs at all...) (Or encrypting data on  your servers network, and clients at the gateway...)
With all that, for less than $20 a user (about $11 for the basic one) you can get an Office365 E series plan, that IS HIPAA, SOX, ISO, and PCI certified.. (Dropbox, hidden in there pages clearly states "at this time", they are not.... )
So ask yourself, albeit in your mind small... Is it actually worth the risk? and DO you want to do business with a company who I think, steps lightly  or makes light, the risks associated with using their product....
Is it worth the risk to your career if you are in technology and you do get breeched and you DID allow dropbox? DO you think you are employable after your name is beside a breech and you make the news? As a CTO, I can promise you, not on my life would I even hear the excuse behind it.. I would never even interview anyone in technology who by their own actions or decisions, caused a breech of data on any sized network.. Yes we all make mistakes, which is why your job in IT is to eliminate any risk, big or small as best you can.. Not open up the worm hole and scream for Alice...)  It is a disaster for  PR.. for a business, (if a competitor found out and leaked who you are.. (gasp) what you did.. and an increased liability to hire someone because they allowed a file sharing service who publically acknowledged and stated they were not PCI, SOX, ISO, HIPAA, or PCI certified
Well.. That's for you to decide... Is it worth a career? Is it worth the loss of your company or customer data?
For me.. It is not... Consumers use consumer products, not businesses... Period.
Answer: An update (1,5 Years later):
Dropbox claims now that they transmit the data via SSL protocol and store them in AES-256-Containers they cannot access themself (without the password).
Comment: That claim turned out to be a lie. http://www.wired.com/threatlevel/2011/05/dropbox-ftc/
Answer: Dropbox recently admitted that they don't use SSL for transferring file metadata between mobile clients and their servers. They do this on purpose, for performance reasons. They don't state anywhere on their website that they do this. You can read about it here:
https://grepular.com/Dropbox_Mobile_Less_Secure_Than_Dropbox_Desktop
Answer: I think they're working on a version for companies to use internally, with more security, but meanwhile, the files aren't encrypted on their servers, so you do have to trust them.
Other than that, I can't see other security risks specific to Dropbox (like information leakage).
Comment: Not true - Dropbox does encrypt all data blocks held on its servers.  However the keys are managed entirely by Dropbox and shared across different accounts.  There are numerous other security issues, google for "Dropbox config.db" and others (since you wrote this answer).
Answer: A lot is going to depend on the policies in place at your company. If its like where I work - where all development I do belongs to the hospital, and not me - then I'd be worried about it being an easy means for company intellectual assets to "wander off".
There are plenty of document management systems that would let you set up something that is only accessable internally or via a monitorable connection.


Grow oyster mushrooms in vacuum cleaner bags?

Question: I'm giving oyster mushrooms a go, growing in coffee grinds in a plastic bag. Having an air filter in a bag, like the ones in purpose made mushroom bags, is a recommended technique.
What if I used a vacuum cleaner bag ? These allow air passage and also filter out small particles. Workable idea ?
I bought some that have a synthetic inner layer that I don't think the mushrooms would consume. What about maintaining a good moisture level by just spraying the absorbent bag ?
I'm a noob so let me know if these are bad ideas. Thanks.
Answer: Normally you want to sterilize the substrate in a pressure cooker so those mushroom bags are designed to withstand pressure cooking for the 90 minutes required.  I suspect a vacuum cleaning bag is both more expensive than the 60c some charge for mushroom bags and not as robust.
Coffee grinds are insufficient on their own to grow oyster mushrooms successfully. You need more carbon added to the mix.
You need to sterilize coffee grounds as otherwise you'll just grow trichoderma.  You don't need to sterilize straw as trichoderma doesn't grow that well on straw and so pasteurization is sufficient. (The same applies to cardboard which can just be boiled.)  That leaves enough good bugs alive to combat any pathogens that might want to colonize the straw.
Comment: I think the bags I got, the synthetic lining might be damaged by pressure cooking, but there are other types, and they are pretty cheap, comparable with 60c. It's an easy experiment anyway. I believe oyster substrate only requires pasteurisation at 80C. Some methods just require pouring boiling water on the substrate and leaving it to cool.
I added torn up cardboard to the coffee grinds, mostly to add a bit of space in the mix. I boiled the lot for a while. I didn't know it was absolutely necessary for feeding them too.
Can a bag or substrate be microwaved without using too much water ?
Comment: That's different. I'll add to my answer.
Answer: It could be working, however I recommend caution, since filtering properties may be very different between the two, even though they look the same or very similar to human eye.
Also, who knows what chemicals are inside vacuum cleaner bags? The problem is that they are supposed to be disposed, nobody predicted mushroom production applications.
All in all, a good idea from the standpoint of creativity, but most likely not so good from practical and safety standpoint.
Comment: Those are good points, and maybe an email to the manufacturer might answer.
What I did do was cut a hole in the plastic bag and tape a square of vacuum bag material over it for ventilation, in an area that doesn't toush the substrate.
Comment: You need to check the pore size of the vacuum bag material.  Mushroom bags use 0.2 - 0.5 micron pore sizes to stop fungal spores from entering.  I would think that a vacuum cleaner has an additional HEPA filter to clean the air coming out.
Comment: Yeah there must be a lot of different types out there, some will be HEPA. Maybe even those solid box types that come in upright cleaners ?


pc becomes slow when launching windows xp mode in windows 7

Question: I have 2gb ram, 250GB hdd, and a  pentium dual core with 2.50Ghz.
I don't know why but everytime I launch the windows xp mode which only consumes 256Mb of ram(indicated in the settings). Makes my computer slow. And I only have google chrome launched.
What do I do to solve this problem?
Answer: In my limited knowledge on the subject, windows xp mode is based on hardware virtulization, which means that as soon as you switch on xp-mode you processor starts to run 2 operating systems at a time. So, what you need to be looking at is the cpu usage which should skyrocket when you turn it on.
Comment: How do I change the settings to use only minimal processor power
Answer: Through Windows XP Mode Settings improve RAM allocation from 512 MB to 1024 or more to get the improved performance & speed.
To do this you need to change Close settings to Shut Down for XP mode, then while windows XP Mode is Shut Down you can edit settings.


Adding new tasks to the current baseline

Question: I would like to ask what the best approach would be in the following scenario.
I have a project with all the tasks.  I've created the baseline but my boss comes and
says: I need you to add these other tasks (let's say 10 more tasks).  How can I add those tasks to the existing baseline or should I create and save a new baseline?
Comment: What is your change control mechanism? Who approved the baseline?
Comment: In addition to Mark's question, what type of project is this?  Is there a buyer / seller relationship and, if so, what type of contract?
Comment: Are the new tasks **new work**, or are they refinement of existing work?  Do they change the project's scope & duration?
Answer: Different scenarios yield a different answer, and even each scenario could have caveats where another answer might be better.  If the project is about building a tangible product, adding and deleting tasks can occur all day long without change orders but also with out a baseline change.  They just produce variances that you need to track and control.  There are caveats to this, however, and some that come to mind are with the type of contract that is in place.  For example, a seller may have added a stop loss clause in the level of effort required to produce the product, in which case adding two activities could exceed that threshold.  Then a formal change, adding budget, and a new baseline are appropriate.  So to answer your question definitively, you need to describe the specifics.  I'll add to my answer once those specifics are known.
Answer: From a strictly mechanical viewpoint, if you are forced to make changes tot he baseline, then I would create a new baseline from that point forward. If you are using a tool, say MS Project, then you can preserve the original baseline to latter use to instruct upper management on the impact of the additional tasks and the changes to the cost and schedule to the project. If you are using EVM, I believe you would be forced to re-baseline, but again I would keep the historical baseline to get management buy in in the future for setting and sticking to the scope. On the other hand, if the new tasking is vital and obviously important to the whole of the project, then re-baselining as new is likely the way to go once management concurs with the new schedule and cost.
Answer: I recommend to review the additional tasks to determine if these will impact your project, such as your milestone dates or project costs. If there is an impact to your existing project schedule or budget, I would seek sponsor/business owner approval for the changes requests and re-baseline the entire project accordingly. If the additional tasks can be done without impacting the key milestones or budget, I would add the new tasks and just re-baseline only the new tasks (In MS-Project 2010, use "Project..Set Baseline..Set Baseline..For..click Selected Tasks").
I have used the "Selected Tasks" re-baseline feature in MS-Project several times. For example, consider a new floor build-out. The project includes deployment for all IT components for a new office floor. If a change request comes in to add a conference room, I can add those new tasks to the project schedule without impacting existing project plans and schedule for the current scope. Of course, the change request needs to be approved and project cost updated accordingly.
Answer: The scope has changed, so you'll need to create a new baseline and new estimates. This needs to be clearly communicated to the customer regardless if they are internal or external.
Comment: Adding tasks does not suggest scope change.  Not at all.
Comment: I don't read features into this.  There are too many scenarios that matter, which makes any other answer except depends inappropriate.
Comment: Depends if by "tasks" we are actually talking features, which jdp's formulation seems to suggest ("I have a project with all the tasks"). Regardless, extra tasks in the process might not be scope change in the strict sense of the word, i.e. functionality, but it certainly is a scope change to the expected baselined process which does not contain these tasks.
Comment: Much as I'm hesitant to disagree with @DavidEspina, I read the question with the same assumptions as Morten K.  Perhaps OP could clarify whether the new tasks are new work, or new elaborations of old tasks? Is the duration of the new tasks _in addition to_ schedule work, or is it more detail & specification of existing work???
Answer: In fact the answer is: it depends. On what?:
You do not need to change scope to take baseline but if it does change you have to.
Baseline is normally link to scope but in real life it's not so simple.
If you want to track correctly your project you might want to baseline the new activities without re-baseline the old ones.
If you have a really tight project with a lot of activities (hundreds) and a solid project management support by your company you'll prefer to not do a baseline on those activities if they do not change the scope.
And depending the software you use, it could give you some opportunities with this situation.
Answer: You have a baseline of what? The Product Breakdown Structure (PBS) or the Work Breakdown Structure (WBS) or both?  Adding tasks sound for me like extending scope, in this case work scope which need further efford and therefore money. If you just update your work packages structure by rearaning your tasks may not have an impact on scope.
Nevertheless any change lead to an update of the baseline and should be managed by a Change Control Board with the clear intension to communicate who have to do what.
Answer: It is unclear from your question these new tasks needs to be added because of what reason. Still if I were you I will create a new baseline if this is increasing my scope of work and subsequently the time.
If the tasks are breakdown of your already present activities with no change to scope then you can add it to the current baseline itself
Answer: In theory, the project baseline is a snapshot of what was approved as the final plan. You should not add or removed baselined tasks as again "in theory" only an approved change request could rebaseline the project.
My 2 cents...
Add the tasks, link/sequence it properly and check the impact to the critical path. If it increases the critical path, a change request need to be created and approved and the schedule rebaselined, otherwise just add the tasks and don't touch the baseline.


Is there any SEO issue to give nofollow for mailto links?

Question: I have seen some of the websites who are using nofollow at mail address.
I want to know about it that if I use it so will I get any benefit from SEO purpose.
Example
Answer: Checking the official doc:

"Nofollow" provides a way for webmasters to tell search engines "Don't follow links on this page" or "Don't follow this specific link." [...]. It is used for untrusted content, paid links or crawl prioritization.

Having in mind crawlers don't follow mailto links, I guess the main point for using that is to prioritize the important links and avoid a waste of time.
Answer: Google probably doesn't crawl mailto: links as it knows there is nothing to crawl. And mailto: links probably don't pass any link juice either. But because there is a possibility that Google might pass the email addresses your link juice, it is worth adding the nofollow tags to these links unless you are 100% sure otherwise.
There isn't any risk of adding nofollow to links that you don't want Google crawling or passing link juice to. And in this case, you wouldn't want Googlebot to crawl the email addresses or pass them link juice. So if there is any flaw in the Googlebot algorithm you're helping it to understand and interpret the link by adding nofollow to it.
Googlebot wouldn't want to crawl the email addresses as it is a waste of crawl bandwidth, but if for some reason its code causes it to crawl it then you're helping it by telling it not to.
But most importantly you're ensuring that you're not passing your link juice to these links, which is worth the few extra bytes of bandwidth that the html code adds.


Change name of website for Intranet Purposes

Question: This is a non-programming question. I'm running IIS on my machine and allowing people to access a website on my machine by making them type http://<mymachinename>. However I want them to access my website by some other name like http://<acoolsite>, but I don't want to rename my machine name. I am running Windows Vista. How can I get around it?
Answer: The easiest way is to use a CNAME in DNS. Failing that (if a central DNS is not available), they'd have to make an entry in their HOSTS file to your direct IP address.
Answer: Since you are not using fully qualified domain names (something.something.com), I'm going to assume you do not have DNS running.  In that case, edit the HOSTS file on each client computer and add an entry for your new name
c:\windows\system32\drivers\etc\hosts
You may have to create this file and be sure that you don't have the ".txt" on the end.  There is typically a hosts.sam file created by windows as a sample you can rename.  Add a line like:
192.168.1.50   acoolsite
Where the IP address is the IP address of your system
Comment: Not necessarily. Windows and Linux can automatically expand hostnames to FQDNs. The internal DNS server can also expand local requests automatically.
Answer: Register a domain name and point it to your IP address.  If you have a static IP you can use http://www.no-ip.com/ to keep your domain in sync.
Be aware that accessing your website inside the network may not work without some configuration.


Currently a Microsoft Money user on PC, need a replacement suitable for Mac

Question: I switched to a Mac a few years ago but kept my old PC Windows running -- only for my Microsoft Money program, which I have used for over a decade... I love it.
Now I need to retire the old PC and I am looking for the best Mac software or on-line finance program to replace Microsoft Money.
I guess whatever I use, I will have to re-enter a lot of data, as I won't be able to import the existing data from my PC on to my Mac, right?
I would appreciate some assistance with this!
Comment: Might be worth mentioning where you are in the world as there were a few country-specific versions of MS Money and that might make a difference to the answers.
Answer: I haven't found a drop-in replacement for MS Money, but I've tried a few of the Mac desktop programs. I settled on Iggsoftware's iBank, which seems to do what I need it to do. It also appears to be able to import transactions from MS Money if you export your accounts as QIF files at the MS Money end, but I never tried it.
Answer: I switched from Quicken for Mac to Moneydance, and have not regretted it.
I see only one weakness in MD compared with Quicken: its reporting is not very good.  Your information is all there and well organized, but sometimes it's hard work to extract it in a convenient form.
Of course a lot depends on what you need from the application, but I strongly recommend you take a look at MD before deciding.
Answer: Long time Quicken user, but I have Bootcamp on my Mac, and one reason is so I can run Quicken Windows.
That's one solution. You didn't mention what version of the Mac OS you're running, but Bootcamp is one alternative if you have (or can purchase) a Windows license. Be advised, Bootcamp 4, which is available with OS 10.7 (Lion) and OS 10.8 (Mountain Lion), officially supports Windows 7 only.
Quicken running under Bootcamp isn't perfect, but it's better than any Mac version, and Quicken 2013 has a mobile app that allows you to view your data & enter transactions via your mobile. The Mac Version of Quicken has been panned by users.
I do use Windows for work-related stuff, so I have a reason for running Windows besides using Quicken.
I've read that Intuit has a market share of more than 70% in the personal finance software sector, and at this point it seems pretty clear that they are not interested in pursuing a larger share via Mac users. So if we ever see a highly functional version of Quicken for the Mac OS, it won't be any time soon.
I've not used other products, but there are many reviews out there which rank them, and some consistently come to the front.
Top 10 Reviews Mac Personal Finance Software 2013;
WeRockYourWeb Personal Finance Software Rankings includes many Web-based alternatives;
Personally, I'm not real enthusiastic about posting my personal financial data on someone's Web site. I have nothing to hide, but I just can't get comfortable with cloud-based personal finance software providers that are combing through my data, Google-like, to generate revenue. Too, it seems an unnecessary risk giving a third party a list of all my account numbers, user names, and passwords. I know that information is out there, if one has the right sort of access, but to my way of thinking, using a cloud-based personal finance software application makes it more out there.


How to disable X Window on startup

Question: How do I disable X Window system on Fedora 11 box from startup at boot time ? Since host is used as a server and not as a desktop I'd like not to waste limited memory resources on X and Gnome.
Answer: The /etc/inittab file describes which processes are started at bootup and during normal operation. This file is used to start X windows system at boot by setting default run level to 5. Edit the file /etc/inittab using a text editor such as vi, enter:
vi /etc/inittab
Find line:
id:5:initdefault:

Replace with:
id:3:initdefault:
Save and close the file. Restart the server.
You can also drop to text mode by typing init command:
init 3

You should then be able to still run the command (if you need X)
startx

Hope that helps
Answer: Remove an init script symlink from '/etc/rc?.d/': it should be called 'S*-gdm'. You can also rename it from 'S*' to 'K*'. The '?' sign stands for a runlevel.

How to disable X Window on startup


What are some examples of minerals that Earth might require in the future from space?

Question: I'm looking to know about minerals that space miners can extract from other planet surfaces or directly from asteroids. Something that Earth as a planet may need in the future.
Comment: The wikipedia article on asteroid mining has a lot of the information you're asking for here. https://en.wikipedia.org/wiki/Asteroid_mining#Proposed_mining_projects
Comment: I have this really vague memory from when I was in college that Germanium, an incredibly useful semiconductor, is fairly rare compared to the grand scheme of things.  However, that memory is really vague and I've too little time to research the issue, so I'm posting it only as a comment and not an actual, useful answer.
Answer: This answer stands as an historical artifact, obsolete because of an edit to the question's tags.
Energy-rich minerals of unknown composition from the surface of Mercury.
Mercury, the planet has an eccentric orbit leading it to be at it's closest point to the sun it is bathed in searingly hot unfiltered solar radiation and cosmic rays. Mercury turns slowly, meaning that in each day the surface absorbs prodigious amounts of solar radiation relentlessly.
This effect has a startling consequence. The surface minerals, when a sample finally made it back to Earth,  - a small fraction of them show an astonishing property - if they are subjected to a strong magnetic field then they re-emit that Energy to which they have been subject for millions of years in the form of gravitational force. The unfortunate Lab assistant who discovered this effect, has received a state of the art prosthetic foot.
On discovery of this property, of course it was investigated further, and found to be controllable, it now represents the biggest potential for space exploration and cheap and clean in-atmosphere flight, and of course cheap energy. - Dangerous to venture to Mercury to fetch in any quantity - this mineral, particularly when the stakes and the demand are so high, the governments and corporations scrabble for control of this fabulous resource, but it attracts a certain "frontiersman" type with nothing to lose and everything to get away from. Over to the writer.
Comment: +1 for *" I'll do the opposite for the purposes of counterpoint."*
Comment: Um, where does it say that scifi cannot be science based? Not in the tag descriptions, that's for sure.
Comment: @StarfishPrime Good question, I'll spend a little time and fish out the hundred or so references from comments by mods and other member to that effect. (Democracy and all). ** Ahh, it seems that I can't search other user's comments. It'll have to remain unsubstantiated for now 'till one of us researches it for a question in meta.
Comment: I removed the scifi tag before reading this.  Sorry to invalidate your answer :-D
Answer: Earth is running dangerously low on helium.
It's important enough that America has a strategic helium reserve of 1 billion cubic meters, although they may be selling it off.
The LZ129 Hindenburg zeppelin was designed to fly with helium, but the USA decided not to sell the necessary amounts required to Nazi Germany.
Comment: We're not ACTUALLY low on Helium, globally, we just haven't bothered to open new mines for it for a long time. If it gets expensive enough, that'd change pretty quickly. Certainly it wouldn't be worth shipping it all the way back here from Jupiter.
Comment: The USA assembled a huge reserve of helium before WW1, when they believed that airships would be a great thing in war. At some point after WW2 they realized that airships are not really great weapons platforms, and began selling off the useless strategic reserve. This has kept helium prices low for more than half a century; but now the former strategic reseve of the USA is mostly gone, and helium prices have risen to the level where they cover the cost of newly extracted helium. That's all. Helium is mostly a by-product of natural gas extraction.
Answer: Nothing.
Earth is made from the same raw materials as asteroids and comets. In fact, the current belief is that the Earth formed by accretion of a piece of the solar nebula, which is where everything else in the solar system comes from.
Now, some of the heavier elements like iron may have sunk in large quantities to the core as the Earth cooled after its formation. But asteroids falling on Earth also deposited a lot of materials on its surface. Meteoric iron is a thing.
If you are going into space for raw materials, you are just getting those materials in a more expensive way.
The only things outside Earth that do not exist on or in Earth are exotic materials that are only formed in extreme conditions. For example, some models predict that Jupiter's core is made of metallic hydrogen. But that is not something you can mine from an asteroid surface.

Note that if you had asked what people might need when far from Earth, then asteroid mining might become economically feasible.
Comment: @Morris The Cat  You are forgetting that mining on Earth produces a lot of pollution.  And it can also undermine valuable stuctures or farmland, etc. And the deepest that can be mined on Earth is only a few miles, while there are hundreds of thousands of asteroids that are smaller in diameter than a few miles and can be totally mined.
Comment: The disclaimer to this answer should be "space travel is still expensive". But if things like space elevator become a reality, the economic calculus would change.
Comment: @Alexander even with a space elevator, there isn't anything out there in the solar system that we can't mine on earth, so it's not likely the calculus would ever change enough to make shipping raw materials TO Earth worthwhile. Raw materials mined in space however would be VERY useful for manufacturing facilities that are ALSO in space, since then you don't have to pay to lift your resources out of a gravity well.
Comment: @M.A.Golding Mining on Earth doesn't have to do any of those things. Those are all limitations of mining when you're trying to do it as cheaply as possible. If you're competitor has to mine their ore in considerably more hazardous conditions and then try to ship it back from Ceres or wherever, cleaning up your own pollution becomes a pretty trivial exercise by comparison.
Comment: It might be worth noting that geological processes in the Earth's crust have concentrated various elements into economic deposits that are otherwise reasonably diffuse. Asteroids are unlikely to possess those same kinds of deposits, which further complicates their viability as mining targets. Examples: Lithium, Uranium, Thorium, REEs, and Copper.
Comment: @M.A.Golding in order to mine those asteroid you gotta have the fuel. All the pollution you prevent by mining in space might be more than offset by the pollution you cause acquiring the fuel you need.
Answer: There's not a huge amount of utility in shipping stuff found in space back down to Earth's surface... after all, we have an awful lot of stuff here and there are plenty of places we haven't yet tried to exploit. Exceptions might be made for materials that are limited in availability and might be largely found in particularly picturesque regions of the globe, or in particularly politically unstable countries, but even then it'd have to be pretty bad to justify going into space to get it. There may be some exceptions... siderophile elements are likely to be common in the earth's core (due to their density) and less common at the surface, but they'll be a lot more accessible in asteroids. Some quite rich people are very interested in the possibilities of mining huge quantities of precious metals but, y'know, there's only so much platinum the world needs and one big find could crash the market.
Some people might say "Helium 3!" which is useful, but the only places you'll find it in serious quantity are gas-giant atmospheres, and you'll need to spend so much energy getting the damn stuff back out again that there'll be little benefit to using it as fuel afterwards.
The benefit in asteroid mining is that the resources you are harvesting are very easily shippable around the solar system, and don't need to be dragged out of a huge, deep gravity well. If you also had refineries in space then it would be vastly cheaper to supply them from space-based sources. It is possible that there are some useful refined materials that are best made under zero gravity and vacuum conditions (foamed metals, maybe?) but it isn't obvious that they'd be useful enough to justify such expensive to set-up and inconvenient to operate industry.
Space-based fabrication might make sense for things that need to be in space... if you can make satellites in space, it'd certainly be better than hauling them up from ground level, but the cost of establishing that industry is going to be very high, and return on investment will take a long time. Some people are more optimistic about the possibilities here, so perhaps it'll be easier than I suspect.
What remains, then, is probably the most boring: ice, and rock. Ice to fuel rockets (because hauling fuel in bulk out of Earth's gravity well is a right pain) and rock to build with (because it makes for nice radiation and micrometeorite shielding) should you wish to put more people and delicate equipment in space.
Comment: Helium 3 is slightly more common in the lunar regolith than it is on Earth.  Not a ton, but maybe a large operation could leverage the economy of scale at it and make a profit.
Comment: @Ryan_L it is possible, but it would be challenging to make mining the moon more economical than using other fusion fuels that are much more easily found, refined or synthesised on earth, at least for the purpose of providing power on earth.
Answer: Minerals?  Not much, until the transport costs come down.
Heavy metals (Gold, platinum, irridium...) are more common in certain classes of asteroids.  However useful these metals are, their high value on earth is due to scarcity.  All the recovered gold in the world would fit in something like a 65 foot cube.  An asteroid with a trillion tonnes of gold would drop the price to the point that gold was used for wiring houses. (Probably not:  Not strong enough)
However some processes may well work better in space -- microgravity may allow very large single matrix crystals -- a process that is difficult here.  Any process that needs a good vacuum can do well in space.  Getting stuff down from orbit is a lot cheaper (but still not cheap) than getting it up.  Probably worth it for anything with a street value meansured in a few thousand dollars per kilogram.  (Computer chips, drugs, vaccines,...)
Hal Clement in one of his short stories speculates that in the cold of the outer planets you may have compounds that just aren't stable at normal temps.  Whether there are any that are abundant enough to become 'geology' is up in the air.


What are some good ways to control costs for groceries?

Question: I find groceries to be one area where I have a hard time controlling costs.  We want to eat well, buy healthy foods, good cuts of meat, etc. and limit eating out.  I find it hard to know what is a reasonable amount to budget...or end up going over what I plan.
Answer: For a while I tried shopping multiple grocery stores, checking fliers each week from three different stores and then making the trip to all three stores to save ten cents on each item. After a couple months, I decided it just wasn't worth it.  So, I picked my favorite store.  I shop once a week, after reviewing the flier and making a list.  I clip coupons and try to only buy what's on my list.  (I confess that coupons sometimes get me to buy a brand or item I wouldn't have otherwise... it's my weakness!)
The biggest place that we save money though, is by paying attention to meat prices.  I know that chicken and pork go on sale for $1.99/lb every 4 to 6 weeks at my grocery store.  When it does, I buy a enough to last until the next sale, and freeze it in single-meal portions.  Steak and fish are special treats, but on the rare occasion that they're less than $4/lb, I'll buy those.  We also try to limit our meat consumption to every-other-day.
It's not worth it for me to obsess over the price of ketchup that I buy twice a year, but on expensive items like meat, and items we use daily, I become familiar with their regular prices and sale prices, and buy extra when it's on sale.  If, like me, you don't have room in your brain to keep track of the prices of everything, stick with the things you spend the most on, either because they're expensive, or you buy a lot.
Answer: Probably my biggest cost saving is to make my own sandwiches for lunch. I take this one step further by buying joints of meat to roast and slice for the filling. This not only tastes better but is quite a bit cheaper.
For example today I roasted a 5 kg ham (about 11 lbs), it cost me £16 to buy (around $25), but I've sliced it, wrapped the slices in foil and frozen them. I've made around 20 packs, each pack has enough ham for sandwiches for me and my wife for a day.
I also do this with beef, chicken and turkey and just get a pack of whatever we fancy out of the freezer the night before so it's defrosted enough to make sandwiches in the morning.
Comment: Rich - nice response here. Whole turkey breast on sale can go for 99 cents a pound, even if there's loss for the bone, it's nowhere near the $6 - $7 /lb of coldcut turkey.
Answer: Definitely don't grocery shop when you're hungry.  Also, watch for sales, and then buy in bulk and freeze it.
Answer: Also make a menu and make a shopping list from that.  It will help you control how much you buy, and help to enforce only buying what you need.  You don't need to limit your menu, but buying what you need in appropriate quantities will help.  Don't forget to add snacking and desserts to your menu.
Answer: Check out the bulk stores like BJs, Sam's Club or whatever else is available to you.  You can definitely save money shopping there but you also need to keep your wits about you as well.  Example, if you're buying in bulk only to let food go to waste, obviously that's not good either...
Comment: You should carefully check the prices on products at these stores to make sure the per-unit price is actually cheaper.
Answer: Cooking cheaply is time consuming. We cook cheaply, but we take more time to do it. May be hard for a busy family.  If you cook everything from scratch, it's usually a lot cheaper.
Also pre-planning meals helps.  If you can coordinate your ingredients, you can save money.  Saving money takes time and practice.
I find that when we're rushed, we waste a lot more food than when we properly take the time required.
Answer: Set aside the amount of grocery money you want to spend in a week in cash. Then buy groceries only from this money. The first week make it a generous amount so you don't get rediculous and give up. And stick to it when you are out of money (make sure you have some canned goods or something around if you run out of money a day short).
And do not shop when you are hungry.
Answer: All excellent answers.  Scott W. already mentioned to look out for sales and many other answers are ways to be smart with portions:  don't overbuy, or be smart with bulk buys.
But, I'm surprised nobody mentioned one of the things I'd consider obvious about saving money on groceries:  coupons!
Coupons can save cash.  We'll sometimes use coupons for brands we'd be buying anyway, or other comparably-priced brands that we're willing to try.  The thing to be careful of with coupons is when the manufacturer is attempting to up-sell you to a premium brand, or trying to get you to buy a product you'd never have bought anyway.
Anyway, we especially like the coupons that Costco sends in the mail once in a while, or those they hand out at the warehouse entrance.  What better way to save than to:

buy in bulk,
at a warehouse club's low cost,
plus get a discount with a coupon!

All the better if the items aren't perishable.  When we have the space and those grocery savings stars are all in alignment, we load up on such items as paper towels, oatmeal/cereal bars, soap, etc.
Comment: no one mentioned getting out and shooting a moose or a deer or going fishing either
Answer: If you are willing to use one main credit card for shopping, use a grocery points rewards card like PC Financial Mastercard.
Pay for the groceries using the card to earn points and use those points to reduce costs.  The only limitation is that you must shop at Loblaws, Superstore, No Frills, Zehrs, Fortinos.
It works out to $1 = 10 points and 20,000 points = $20.  So that works out to spend $1 to earn back $0.01.
Comment: Many reward programs from credit cards offer a certain percent for groceries. Mine is 2% for example, and it is not limited to any certain stores.
Answer: This may not help with the overall grocery issue, but I find that there are items that I can do without the name brand version of.  A handy rule-of-thumb is to start with the least-expensive brand and work your way up, until you find one that your family likes.  For instance, I've learned I can do without French's mustard in favour of no-name, but there's no way I can live without Kraft peanut butter.
Answer: Keep a notebook. (or spreadsheet, etc. whatever works)
Start to track what things cost as few can really commit this all to memory.
You'll start to find the regular sale prices and the timing of them at your supermarkets. I can't even tell you the regular price of chicken breasts, I just know the sale is $1.79-1.99/lb, and I buy enough to freeze to never pay full price.
The non-perishables are easy as you don't have to worry about spoilage. Soap you catch on sale+coupon for less than half price is worth buying to the limit, and putting in a closet.
Ex Dove soap (as the husband, I'm not about to make an issue of a brand preference. This product is good for the mrs skin in winter) - reg price $1.49. CVS had a whacky deal that offered a rebate on Dove purchase of $20, and in the end, I paid $10 for 40 bars of soap. 2 yrs worth, but 1/6 the price.
This type of strategy can raise your spending in the first month or two, but then you find you have the high runners "in stock" and as you use products from the pantry or freezer, your spending drops quite a bit. If this concept seems overwhelming, start with the top X items you buy. As stated, the one a year purchases save you far less than the things you buy weekly/monthly.
Answer: Please stay away from snakes.
Don't use a credit card to buy your food. Those credit companies will eat you alive. Those are reward points they're giving you. It's like the casino giving you a free $50 to start out with. They designed the game. They are going to win.
As for groceries, if you are a coupon clipper, check out thegrocerygame.com:
"Teri's List is a weekly publication of the lowest-priced products at your supermarket or drugstore matched with manufacturers' coupons and specials - advertised and unadvertised. Teri does all the hard work and research, and presents it to you in a straightforward format. Log in each week and print your list!"
Nathon
HouseholdBudgetNerd.com
Family Budgets for Both of Us
Comment: Nathan - in the great Venn diagram of life there are the card users who carry a balance month to month, and those who pay in full every month. The pay in full group has no reason to avoid cards. I have a card that gives 2% back on all purchases, the rebates going into a college savings account. It just passed $14,000 and we still have 4 years till college starts. This account will pay for a semester of school. Never paid interest, or fee on this account.
Answer: You may use an app called Flipp (or one that serves your area) to check fliers while in the store.
If your preferred store has a price match policy, this can save you a few bucks every trip. Just look up at the app what you are buying and price match it over the cashier. It may or may not work on your store, always ask first.
Try to learn some of the products you always buy regular prices. That way you can tell a real special from a fake one, like I write here about the 2/$5 specials.
Buy generic brands for things you don't care that much, like bleach and other cleaning products that does not have a real quality difference from the branded ones. Try different cheaper brands until you find one that is ok for you.
There are lots of ways to save money on groceries, you just need the will to do so ;)
Good luck!


Should I cooldown before shutdown?

Question: I am working with Ender 3 Pro and in menu it has an option to cooldown. Is there any need to cooldown 3D printer before shutdown or can I just shutdown without cooldown?
Comment: Welcome to 3dPrinting.SE!
Answer: Depending on what material you print it it most likely a good idea to let the hotend cool down before shutting off the printer (fan).
For example if you shut down the printer right after you print a PLA part, at 190 - 220 degrees Celsius, your hot end will still be that hot and will suffer heat creep without the fan running. The next time you fire up your printer the hotend will be jammed and you will need to clear it before starting a print.
This is obviously situation dependent but in most cases you should let your hot end get below the TG (glass transition temperature) of the material before turning off the printer.
Answer: That option you are referring to, is meant to manually shut down power to the heated bed and hotend, there is no timed cool down period other than you timing it. This is a handy option if you fiddled with either the bed or the hotend; e.g. to insert new filament.
A cool down period can be very useful depending on the printer. Those cold-end cooling fans usually are very noisy, so people cut them of (that is not always possible/wise, but is being done out there), disable them after printing or shutting down power of the printer as a whole. Some type of hotends are prone to have heat creep up the hotend and  soften the filament so that it can clog up the hotend. I've seen this happen on Ultimaker printers where the cooling fan was not spinning because some fine strings where sucked up.
To minimize the noise level of such cold end cooling fans you can put them on a relay switch and have e.g. OctoPrint schedule the print to be on for e.g. 2 minutes after a print failed or finished, works perfectly, and then you have your cooling down schedule/period.

Should I cooldown before shutdown?


How do I tag all my friends in a Facebook photo album?

Question: I have uploaded several photos to Facebook with friends in them and want to tag them all.
How do I tag all my friends to a particular album?
Answer: You have to do it manually....
Answer: There is a bit of an update as to how you can achieve this.
Go to the album. And select the friend/page you want to tag.

Now start clicking away on the photos, if you don't care where in the photo it is tagged you can iterate through a lot of photos this way.
Repeat for the rest of the friends.
This is tad faster than the original flow of tagging while uploading.
Otherwise you can also create an event/trip and add the album to it.

The third way which does not explcitly tag the friends within your album but the album itself is to go album in the timeline and then tag your friends.
Answer: You should make a list with all your friends in. Then you can tag the list rather than each individual friend.


Using OverviewClass in ArcObjects?

Question: I want to display an Overview map - I know how to do it using a separate PageLayout or MapControl - but I noticed ESRI has an OverviewClass - how do I make use of this with the AxMapControl?
Answer: Instead of using the Overview class, I would just use two mapcontrols: a main map and an overview map.
The overview map would listen to ITransformationEvents on the main map's displaytransformation.  When VisibleBoundsUpdated fires, update the overview map (centering it on same point as main map, but not changing the scale).  In the event handler for the overview map control's afterdraw event, draw a red rectangle on the map representing the extent of the main map.
Answer: You should be able to use it the same was you use for example a North Arrow, because it's implementing IMapSurround see: Concepts & Samples: Map surround
Comment: I reworded my question to be a little more clear - I am trying to use it with an AxMapControl, not an AxPageLayoutControl.

Using OverviewClass in ArcObjects?


Are BIP 100, 101 and 102 being voted on now by Bitcoin miners?

Question: Are the BIP 100, BIP 101 and BIP 102 proposals being voted on now by miners? What is the procedure for a bitcoin miner to vote for a particular BIP and where can a tally of votes be viewed?
Answer: There isn't any blockchain voting for accepting a BIP: See How is a BIP accepted? and BIP0001.
Rather, the BIP is accepted or rejected on the basis of consensus. Consensus is never defined, but even if you interpret it fairly broadly, I don't think any of the three will reach consensus.
There are frequently blockchain votes about activating the new rules, but that's less of a mechanism to measure acceptance and more of a way to only deploy the new changes once enough of the network runs them that the switchover won't be disruptive.
There is a related issue, which is Bitcoin-XT, which grew out of several developer's frustrations with the process. That proposes to alter the blocksize according to BIP 101 once more than 75% of the blocks are created by Bitcoin-XT nodes. But that's not something within the BIP process.
Comment: It's necessary in understanding why it isn't up to miners to make breaking changes, and why voting for it with a coinbase string isn't completely appropriate.
Comment: @Bitcoin Nor are hardforks entirely up to Bitcoin Core developers. I sense that we're getting into an argument that we've had before. I feel that my answer to the asker's question is complete. If you disagree, you're free to write an answer.
Comment: You might want to differentiate between hard and soft changes, as there's a catastrophic difference between the two.
Comment: The distinction is important, but it's out of scope of the question, and has been elaborated elsewhere.


How can I remove dead skin from my back?

Question: I've been under the sun for too long. My back starts peeling badly. I can rub the skin off slowly but is there a faster way to do it? I tried wet towel but that seems too slow and not so effective for me. Is ther any alternative?
Answer: I consider this scenario similar to the lips dead skin, if we remove dead skin then after certain period of time it will appear again.
Don't try to remove dead skin, If you try to pull dead skin your normal skin will also get pulled out. Better apply some moisturize it will help you to get rid from the dead skin irritation and let your dead skin remove automatically.
Answer: The sun is actually killing your skin cells. You should stay out of the sun or wear sunblock. This may prematurely age your skin and you are at risk for more cancers.
Your really don't need to remove the dead skin, as it will flake off by itself. A moisturizing lotion will help if it itches. Use a moisturizer that contains aloe vera or soy to help soothe sunburned skin. Lotions that have something called aloe vera in them help make your skin feel better. Be careful not to use lotions or creams that have any of these things listed in the ingredients: petroleum, benzocaine, or lidocaine.
There are soft bristled, long-handled back-scrubbing brushes you use in the bath / shower (you see them in older TV/movie media).


Most successful investors using academic-based framework?

Question: What are the most famous/best performing absolute-return funds employing approaches based on mainstream finance theory (i.e., theory presented in Journal of Finance, AER, Econometrica, using typically factor models)? I am asking because I know certified outstanding managers using fundamental analysis (e.g., Buffett, Robertson, Cohen), and bottom-up algorithmic approaches (e.g., Simons, Thorpe, Malyshev). However, the typical quant asset managers that use some kind of factor model are either institutional investors with mediocre performance (and usually actively managed to a benchmark), or absolute return fund managers with either terrible performance (GSAM, LTCM), or unremarkable one. In short, does anyone have an example of such a fund with average returns in excess of 15-20%/year over an extended period of time?
Answer: One might probably mention Yale's Endowment under David Swensen which generated returns of 13% per annum over the past two decades (as compared to the 8 or 9% average return of college and university endowments).
Now, I would not label Swensen's approach to portfolio management with a pure absolute return strategy tag but he definitely uses some insights from the academic finance theory. Swensen speaks about his investment philosophy in this lecture (which is a part of Robert Shiller's course on Financial Markets).
Answer: That's a tough question to answer.   The "quant business" is a business.   Some quants sell low-grade/low-volatility results, some sell fast-moving/unpredictable results, some sell industry targeted results, etc.   It depends on what the buyer wants to buy.   There's a market for everything.   Haven't we all met people that think they're going to win the Lottery?  ...beat Vegas?   ...predict the price of gold?   It's their money.  If they want to waste it, there's always someone willing to get on the other side.
Then there's a part of the quant market that is real.  They spend a lot of time trying not to lose money, and to make money in a less volatile way.   I don't have money with the following guys, but here's a big, medium, and small organization:
Ray Dalio, Bridgewater Assoc - http://www.bwater.com/home/our-company/company.aspx
Cliff Asness, AQR Capital - http://www.aqrcapital.com/cliff.htm
John Hussman, Hussman Funds - http://www.hussmanfunds.com/
Comment: Don't know Hussman, but would say that the performance of AQR, although good overall, is not a sterling one. They lost 40% in the opening months of the fund in 1997-8, and then they lost a lot in 2008. All of which has not counterbalanced by outsize annual returns. Dalio's strategies span the gamut, where for "gamut" I mean "I don't really know what they do". But they seem to have the typically choppy performance of a fundamental fund, with lean years (2009) followed by fat years (2010). Not what you'd expect from a quant fund.
Comment: Asness also got bit in the late 1990's when everyone and their monkey bought tech stocks. Asness was short garbage and long stable worthwhile companies. Everyone/their-monkey thought they'd get rich on stocks. They had no clue about what they were doing, but the herd was big enough that as they bought tech garbage, they sucked money out of worthwhile stocks. Asness was on the wrong side at exactly the right time. It turns out that he was right, but for a while he really looked wrong. My point? Quant funds can't be "future neutral" or in this case, "idiot/monkey neutral".
Answer: I believe the reason no one has been able to come up with an example of a quant fund employing the academic factor-based approach with stellar performance is because there aren't any (at least not any with decent sized AUM).  For a while, now, there has been a debate amongst institutional investors and quantitative professionals as to whether quant is dead.  The alpha factor approach is definitely not the kind of magic bullet many people thought it would be.  In part I believe the reason for its perceived failure is that expectations were too high to begin with.  Even @gappy's question, which asks about 15-20%/yr over an extended period, shows this.  Such returns are simply not possible on a large asset base.
Over time, the alpha factors have morphed into risk factors.  The latest fad now appears to be factor timing (see EDHEC, Deutsche Bank, JPMorgan, Bernstein, Macquarie, and others).  Yet practitioners acknowledge that factor timing is much harder than it appears.  There also seems to be some emphasis on finding new and original data sources, but after a while even these "new" data sources will become old.  The paradigm itself is being called into question.  In fact, much of the debate now is as to whether there ever really was an edge in these factors, or perhaps GSAM, AQR, and the other major quant equity firms were merely benefiting from the huge inflows into the space pushing valuations in their direction.
On a final note, I've never heard of Malyshev, but it's not clear that Simons and Thorp didn't/don't make abundant use of academic finance research generally.  Merely that they do not employ the factor paradigm as an organizing principle behind their primary strategies.  Even Simons, btw, has his own foray into traditional factor-based quant equity in the form of RIEF.  Reportedly, this has not worked so well, with the fund seeing major losses in 2007, 2008, and 2009.
Answer: This is the question I've been waiting for! I work at a large outsourced CIO shop and spend a lot of time evaluating different managers and the strategies they come to us with. I also know a number of people I went to school with that are now at quant funds. There are a couple of important points to keep in mind:

Every respectable quantitative manager has a flagship strategy that will never accept capital from outside investors. Most of the ones I've seen tend to have around $1 bil of capacity and never open up to anyone not employed by the firm. The returns I've seen for those funds are all incredible (over 20% CAGRs, with Sharpe ratios over 5), but if you don't do what I do or work for a quant shop, you're never going to know about these funds.
The lifecycle of quant funds tends to be different than other funds. If you're Julian Robertson, Chase Coleman, or John Griffin, you have an investing acumen or edge that would take someone years to mimic, assuming they can even come close. Quant funds are only as good as the unpublished investment anomalies they've analyzed. As published research catches up to their research, their performance will deteriorate. So, you tend to see fewer quant firms that have long, impressive track records.
Lastly, because they rely on investment anomalies to earn their bread, most quant funds focus on asset gathering rather than straight outperformance. A great example of this would be the plethora of low vol strategies coming to market. These funds look great in backtests because they all exploit the low vol anomaly, and they have a ridiculously high capacity because most low vol stocks tend to have large market caps. If you have the mutually exclusive option of generating higher outperformance by making a few tweaks to a low vol strategy or sacrificing some performance so you can take in another five billion, you're going to go for the option that puts more money in your pocket.

Hope that helps answer your question.
Comment: 20% CAGRs and SRatios in the 5 region does not compute. Strategies with 5 Sharpe's and around 20% returns imply close to zero % drawdowns and hence means the strategies/managers square each profitable trade as prematurely as they cut losses early on. A very rare strategy to spot such return/SR profile.
Comment: I understand your skepticism; maybe I should have rephrased my first point. There are only five funds I've seen with those track records; there are very few quant shops that are truly outstanding. None of the great flagship strategies I have seen had drawdowns greater than 3 or 4 percent over 7-10 years, which would be consistent with your expectations.
Comment: yes but they would have way higher than 20% annual returns
Comment: gross, but not net, of fees
Comment: Maybe my stats is way off base here but a strategy with such low draw downs and 5+ Sharpe ratios does not return less than at least 50%, gross or net, regardless of trading frequency, strategy approach unless we are talking some odd boundary cases ( funny return covariances on 5 or 6 trades a year which I assume is not the case here). Just saying you may want to double check those CAGRs.
Answer: If it was possible to simply pick up some papers and adapt them and produce returns that trade would quickly disappear since it would be an inexpensive way for firms to produce excess returns. If you have a factor that produces alpha you had best not publish it or all returns associated with it will disappear.
I have found most of the value in the academic literature unlocked by our group to have come from other quantitative disciplines with signal processing problems. Generally most of the academic literature on finance is either behind the times or not possible to implement in a profitable way.
Answer: Joel Greenblatt (Columbia Business School) has some outsized returns. However, he does not use an equilibrium factor model framework. I would consider him a practitioner who has done well and therefore teaches.


Why was "Inadvertent use of = instead of ==" question locked?

Question: Other than being old, there isn't anything else going on. It hasn't been massively edited through its life. Almost all its activity is focused on '08. It isn't terribly popular by SO standards, nor high quality. It doesn't seem to fulfill any criteria that merits locking. Why was it locked?
Comment: You probably didn't look at the timeline.  Yet another good call from that mod.
Comment: To put Hans comment into context, I have a user script that puts the timeline besides the flag button... so, obviously I did look at the timeline.
Comment: Sorry for the late reply - we are in different timezones. I wasn't intentionally avoiding your question :)
Comment: @SamuelLiew don't worry. I know some of these questions can take up to 72 hours for the right people to answer it.
Answer: This answer was added recently.
The moderator looking at this particular question must have surmised that this answer didn't really add much else to the (already popular and well-answered) question, and believed that locking it out from new answers was the right decision here.
For the above reason, I could agree with the decision to lock it.  There's no sense in allowing others to keep adding answers to this post since all of the major talking points would've been covered by now.
Comment: Maybe it should be.  The most recent answer (at the end of March) only regurgitated information that was already there.  Might be worth a custom flag.
Comment: @Braiam:  What new insight could you *possibly* add to the question you referenced in your OP that ***hasn't*** been discussed *ad nauseam* in earlier questions?  What new insight could you *possibly* add to the Git question you referenced here in the comments?  Why not just cut the problem off at the source and stop new answers from regurgitating old answers?
Comment: "keep adding questions to this post"?? You can't add questions to questions, only answers. "with the decision to close"?? What question are you reading? It was locked, not closed.
Comment: @Braiam:  You knew what I meant!... :)  I've corrected it, though.
Comment: Also, we don't lock questions on that basis, otherwise why https://stackoverflow.com/q/292357/792066 isn't locked?
Comment: Are you serious? I mean, if it doesn't adds anything that means that the answer *should be deleted* "Answers that do not fundamentally answer the question may be removed. This includes answers that are: [...] exact duplicates of other answers" not the question locked.
Comment: Let me see if I get you: you want to lock every old question because you believe that there shouldn't be a new answer ever? That doesn't sounds right, specially in a moving target like programming.
Comment: @Braiam: If every new answer to the question rehashes older answers and there can't realistically be any further answers which will shed new light on the problem, then locking it is *fine*. This was also done for the Java NPE question too, and that make sense. There's only so many ways to prevent NPEs.
Comment: @Braiam: If new answers get added that don't add any value and there is a high chance that ever aspect is already answered, then yes the question should be locked. Also note, that a moderator most probably stumbled over the question because on of the other answers has been discussed recently on meta. It seems that this moderator also cleaned up the question and made at least one answer to a comment.
Comment: "If every new answer to the question" conditioning *it's becoming a problem*. This question isn't an **ongoing problem**, the newest answer posted before that one was in '10. SO has enough tools to deal with the very sporadic rehashed answer. BTW, that very answer claims that the content it pushes is already there.
Comment: @BDL for that there is the new answers old question queue. To evaluate that. Locking is using a cannon to kill a mosquito.
Comment: But realistically: Is this discussion going somewhere? @Braiam: State why you think it is bad that this questions is closed in your question or leave it. This whole thread looks like a discussion just for the sake of the discussion.
Comment: @BDL why are you implying that's what I want. That's not what I want. I want to know why a question was locked, what kind of through process went to reach that decision, and verify that said through process isn't flawed in way that goes against the goals of SO, which will always be my ultimate reason to rise any meta question.
Comment: "questions is closed" It was not *closed* @BDL. It was locked, ie. you can't vote nor edit the question. At least have the respect of reading the question before going after my motives.
Answer: Here's a couple of reasons why I decided to lock the question:

First came under our radar two days ago for a declined NAA flag on the Yoda answer (I saw, but was handled by a different mod)
I then handled a NAA flag and ended up converting a different comment posted as an answer
A new answer was then added to the 10-year old question that didn't add substantial information
Followed by "more than 30 answers" (auto-flag), that prompted me to review the question and all answers again
Primarily opinion-based
Already has a great answer

Since this question was asked 10 years ago, I could have used a historical lock, which would prevent editing/voting of everything on that page. However I decided to give the less drastic wiki lock a trial so the existing answers can be improved if necessary.
Also refer to this related answer and linked posts in the answer for further background & usage of the wiki lock: https://meta.stackoverflow.com/a/280534/584192
If you do have a reason why any question should be unlocked, simply flag it for review (I have already appropriately unlocked a few other questions this way).
Please provide feedback in the comments below if you feel the question "Inadvertent use of = instead of ==" wasn't locked appropriately.
Comment: @Braiam There are four types of question locks. The one I used does not prevent anyone from editing the answers (except <100 rep users). Can you please let me know if you can't edit the answers? Additional reading that supports my decision and explains why use a **wiki lock** instead: https://meta.stackoverflow.com/a/280534/584192
Comment: Now, I wonder, why not close it as opinion based? It has the same effect (doesn't allow new answers to be added) and it doesn't make said answers forfeit their tag score nor their future reputation gains, while allowing someone to edit the question to make it fit better (herculean task at that, but it's not impossible).
Comment: @Braiam for the same reason why I didn't use a historical lock. Since it's an old Q&A, encouraging others to continue contributing via edits is a better outcome for the greater good. If it's closed, it's less likely one would contribute.
Comment: And the lock prevents just that... Look, I don't know how much you know of the system but questions and answers can be edited by anyone, unless they are locked. When you locked the question, you are actually *preventing people from editing*. In net terms there are less posts that can be edited after the lock than before. Closing on the other hand doesn't have said effect.
Comment: Simple, **I didn't mention *answers* at all.** You made that assumption. I said post and the question is *a post*, which is in dire need to be edited to make it non-opinion based, which the lock prevents. In a lock vs close scenario, the locks always have less post available to be edited.
Comment: @Braiam since the question has already been reviewed by three other editors, and answers have already been provided, we want to keep the context as asked. I also do not see any further need to edit the question.
Answer: I don't think the answer referred to by Makoto was the cause of the lock.
I think this answer, that has been removed and converted to a comment recently, is the culprit(Screenshot for <10K). After removing that answer, there were 3 deleted answers on the question.
Attention may have been drawn to the post by another answer, but my best guess is that removal of a bad answer, even though it was initially posted long ago, is the reason for the lock.


Ask a contributor for citation

Question: In academic practice and code of conduct, it is fair to obligatory to mention authors and sources of information. Some of the contributions on this site merit to be cited. However, the authors are anonymous. Is there a way to contact the authors whether he or she would appeciate to be cited in a non-public conversation?
Comment: Forwarded this to Global Meta https://meta.stackexchange.com/questions/361543/ask-a-contributor-for-citation
Answer: There are several ways to proceed here.

I agree with @curiousdannii that most academic institutions will accept a quote or citation from any source provided it is appropriately documented with references internally
Some of the users here have contact information in their profile section and welcome private contact
For those who wish to remain anonymous, it is possible to ask the person to contact you by leaving your contact information either in a comment or in your profile.
Answer: I'd just comment below their answer asking how they would like to be cited.
If they never reply, then you can cite them using their username/pseudonym here.
Comment: @Jeschu Actually probably the majority of users here are not academics (and if they are, theology is a different discipline to Biblical studies.) There are lots of regular lay people, some religious workers, some Bible college students. In any case, academics are used to citing weird things. If an idea that is useful to you comes from some website, then you cite it with whatever author name that website uses. There's absolutely nothing wrong with citing a username from this site in a professional research article. But as I said, try asking first. They'll probably tell you their name.
Comment: But you do not cite an anonymous author
Comment: @Jeschu Everyone here can be identified by username, even those who have the default userXXXXX names. And most people pick a pseudonym.
Comment: I suppose the majority of the users here are professional theologists, some of them professors or Ph.D. students. In a publication, you would not cite or mention thanks to curiousdannii on stack exchange but a real person.
Answer: Welcome!
A number of contributors also have included on their profile page links to their contact information, or to a website they run, which in turn would provide a means of private correspondence.

Ask a contributor for citation


Do common terms for animals such as amphibian or reptile fall somewhere in taxonomy levels?

Question: Where in the "ranks" of taxonomy (domain, kingdom, phylum etc.) do common words used to describe animals such as amphibian and reptile fall?
Answer: This is all a matter of how we define terms, and which definitions are scientifically useful.
Traditionally (since Linnaean times), organisms were classified based on their outward similarities (phenetic systematics). As such, the traditional definition of reptile, which is the same as any common usage that I've heard, includes organisms like snakes, lizards, turtles and crocodiles but does not include birds. This is the class Reptilia. As evolutionary understanding increased, however, it was found that some reptiles, like crocodiles, are actually more closely related to birds than to other reptiles. This makes the common use of reptile a paraphyletic classification.
In modern phylogenetic systematics, organisms are classified in monophyletic groups, or clades, that include an ancestor and all of its decedents (ie it is based on evolutionary relationships). Thus the class Reptilia, since it is paraphyletic, is essentially meaningless in this system. In order to have consistent nomenclature, you could either say that birds are reptiles (a new, cladistic meaning of the term, but which contradicts traditional/common usage) or come up with a new name that includes all traditional reptiles and birds. Taxonomists taking the latter approach use the term Sauropsida for this clade. Sauropsida does not have a taxonomic rank like class because such ranks are useless in cladistics (and actually quite arbitrary even in the traditional system).

So, to specifically address your question:
In phenetics, both Reptilia and Amphibia have the taxonomic rank of class.
In phylogenetics, what we commonly consider reptiles and birds are grouped in a single clade that can be called Sauropsida or Reptilia (re-defined to include the clade Aves) depending on who you ask or which paper you read. Amphibia form a clade.
Perhaps the most important take-away message is that taxonomy is largely un-standardized.
Comment: Actually phylogenetic nomenclature is extremely well codified: https://www.ohio.edu/phylocode/ (some would say too much so).
Comment: @kmm I'm not a taxonomist, but as far as I know PhyloCode has not been widely adopted. Even though standards do exist, taxonomy as a whole is not standardized (at least not well). That said, I can remove the last sentence if you think it is misleading.
Answer: Amphibians form a class in phylum Chordata.
Reptiles, when considered as a taxonomic group, are also usually seen as a class in phylum Chordata. However, some scientist don't see reptiles as a valid taxonomic group because they are not monophyletical and modern taxonomy tend to accept only monophyletical groups.
That is, according to the taxonomy I was taught at school some decades ago, fishes, amphibians, reptiles, birds and mammals where classes in phylum Chordata. Nowadays, it is known (and stressed) that some reptiles are evolutionary closer to birds than to some other reptiles: there were common ancestors of crocodiles and birds that weren't ancestors of turtles.
Since monophyletic groups are defined as all descendants of a common ancestor, reptiles defined in the usual sense aren't a monophyletic group because they don't include birds. Therefore, some taxonomist either expand reptiles to include birds (and then "birds" and "reptiles" can't be both classes, although remaining valid) or just discard reptiles as a valid taxonomic group.
In the other hand, extant amphibians seem to descend from a common ancestor, and therefore they aren't questioned as a valid class.
Interestingly, fishes, regarded as a class for long time, are also being questioned as a valid taxonomic group, since some fishes share a common ancestor with tetrapodes (terrestrial vertebrates) which is not an ancestor of some other fishes.
Comment: That's also a reason for some evolutionary to stop using reptiles as a taxonomic group instead of extending it: reptiles keep being useful as a word, just like "herptiles", "fishes" or "domestic animals", all of them useful although invalid in evolutionary taxonomy.
Comment: Evolutionary taxonomy is a ridiculous, nonsensical, complicated mess and we should go back to traditional morphological taxonomy (classification based on physiology, shape, and function). If it looks like a duck, quacks like a duck, and walks like a duck, common sense dictates that it probably isn't a reptile.
Comment: @user1258361 which works right up until you start dealing with extinct organisms in which modern notions grouping break down, where do you put pterosaurs, how about dinosaurs, how about feathered theropods. How do you deal with the fact crocodiles may be secondarily exothermic, or that turtles have lost their temporal fenestrae, hence the use of evolutionary taxonomy.
Comment: @John create new classes for those and group as normal instead of breaking existing terms that have been widely accepted for decades and remain well-defined according to their traditional definitions in common use. An article years back mentioned that dinosaurs ran on a spectrum between warm/cold blood, so you could well argue that they deserve their own set of separate classes.
Comment: so you have classes inside other classes inside yet another class inside yet another class, making the term "class" pointless. hence why ranks are being abandoned. Cladistics is still based on morphology just accurately compared morphology. Crocodiles share more features with birds than they do with snakes so why would you group them with the latter. PS there is no evidence for cold blooded dinosaurs.


Execution of Javascript inside a Custom Button is deferred till the end of function

Question: We display inside a tab in the Sales Console a custom object page layout with a custom Javascript button. Once the user clicks on that button, the custom code performs some operations on a Salesforce custom web service APEX class (by using the script connection.js) and based on the response, eventually opens a new tab in the console (by using the script integration.js). This functionality works fine.
When the system is busy working, not to let the user press the button twice or getting confused about the state of his request, we want to disable the button and display the waiting cursor. So we created the following code inside the button:
<code>var btnService = document.getElementsByName("check_lead_contact");

btnService[0].value='Checking, please wait...';
btnService[0].disabled=true;
document.body.style.cursor = 'wait';

//JavaScript code calling APEX Webservice by using connection.js
//Javascript code opening new Sales Consoel tab using integration.js

document.body.style.cursor = 'default';
btnService[0].value='Check Lead/Contact';
btnService[0].disabled=false;
</code>
However this code does not work, the button does not get disabled and the cursor does not change to "wait". However, if I inspect the code with developer tools, I see that in the console the state of the JS variables linked to both the button and the cursor change but such changes are not reflected in the UI. All the changes in the UI are made once the function ends and not the state variable change, as it is supposed to be, most likely because the call to the webservice somehow make the function hangs.
We asked help to SF support that replied to us that they do not offer support for buttons containing references to either connection.js or integration.js, although they are included in official SF documentation. Does anybody know a way to solve this issue?
Answer: If you do slight modification to your ending lines I hope it works.
Can you try this....
document.body.style.cursor = 'default';
btnService[0].value='Check Lead/Contact';
setTimeout(function() {btnService[0].disabled=false;},1000);
Not sure about whether it will change the first two properties (cursor & Value) but it will definitely disable the button.
Let me know if it works.


What is the red zone in rugby (or American football) and how did it get that name?

Question: What is the red zone in rugby (or American football) and how did it get the name red zone? I couldn't see anything mentioned about this in the Wikipedia page for both games.
Comment: Rugby does not use the terminology 'red zone'. Some commentators sometimes use that term in Rugby League but it is not in common usage.
Comment: Are you asking one question or three...for one sport or two?
Comment: @edmastermind29, Since all of them are related, I thought of posting as single answer. I have checked meta before posting this and saw this question [Is it okay to ask multiple questions of the same topic in a single question?](http://meta.sports.stackexchange.com/questions/334/is-it-okay-to-ask-multiple-questions-of-the-same-topic-in-a-single-question). So I thought it is okay to ask it this way. If you feel that it should be separate questions, I can post different questions for each of them. I was thinking that both sports are almost similar in nature so thought the answer will be the same.
Comment: Understood. You make valid points. Just making sure your question is focused well.
Comment: @Bogdanovist agreed, I have never heard "the red zone" used in rugby, the common term is "the 22", or something similar to that, referring to the zone between the try line and the 22-yard line. Essentially it's the same thing but the term used is different between american football and rugby.
Comment: @Bogdanovist, Thanks for the comment. I wasn't sure about that. But as per [this wiki page](http://en.wikipedia.org/wiki/Glossary_of_rugby_league_terms) there is a term in that name in Rugby.
Answer: It is my understanding that the term has military origins.  A red zone in military terms is the danger zone, generally close to the enemy (red having been a symbol for danger for a long time).  The term is analogous to sport as the last 20/22 is where you are more likely to suffer the danger of conceding to the opponent.
I see that Merriam Webster has the first usage in sport at 1983 but the military/danger  use predates that somewhat.  Indeed, there is the 1966 film, "Red Zone Cuba", which is centered around a military facility.
During World War I, the decimated areas of France were known as the Red Zone.
To sum up my answer, the term "Red Zone" has been used in various contexts as a term for danger.  Its application in sport is to represent the danger of your enemy and it was first coined by ex-Redskins coach Joe Gibbs in 1982.

The term "red zone" was coined by then Washington Redskins coach Joe Gibbs in a 1982 interview with the Washington Post. Gibbs used the term to describe the heightened sense of urgency on both sides of the ball when the offense gets close to scoring. He called efficiency in the red zone an important part of that team's success.
Answer: From Wikipedia (as linked by Orangecrush)

The area is not literally colored red and the term is used mainly for statistical purposes

As far as I can tell, the etymology is that they needed a name, and "red zone" sounded cool. Nothing particularly special or notable.
Answer: Wiki defines red zone as,

The area between each goal line and their respective 20 metre lines, that is, their own quarter, may be referred to as the "red zone".

You can read other terminologies of rugby and american football here and here.
Comment: Thanks. But how did that name came?
Answer: From here, and the description of the zone, red zone(s) are the vital area for scoring a touchdown (from most rushes and passes), and it also the nice range for the field goal kick, too. Danger can be detected by the defense, so it seems legit to name that area the "Red Zone".


OS X 'Quick Look' stopped working

Question: I am running the latest updates for my Mac OS X OS and I just realized that Quick Look is not working. Typically I select a file via single click in my finder and press the space bar this would bring up Quick Look. It currently does nothing.
I looked in the Console and it is not generating any errors. Is there a known fix?
Comment: Please tell me you've tried restarting...
Answer: You can invoke quick look manually from the commandline to see if there is something wrong. Open a Terminal and list all available files with the command ls. Now run
<code>qlmanage -p something
</code>
Where something would be any item shown by the previous ls command. It can be a directory, a file, just about anything. In fact, you can substitute something with a single dot and it should run too.
Running this command will try to open quick look manually, and you can see on the console all the possible warnings/errors which can help you diagnose a problem. For instance, you may get the error Can't open input server pointing to a file, which tells you that you have an input manager either incompatible with your current OSX version or just behaving incorrectly in some way.
Answer: This is a long shot but it's worth mentioning: if you are running SugarSync, it could be what's preventing you from using Quick Look.
I'm not sure why this is, and I've filed a bug report with SugarSync (today). For me the problem with Quick Look not reacting started around the time when I installed SugarSync and disappeared the second after I had uninstalled it (how-to instructions at SugarSync's site).
Answer: Thank you very much elias, this was the problem
I didn't have to uninstall, just quit sugarsync manager. I've also sent them a support request.
This article on SugarSync help says that the latest version solves the problem, and suggests the following workaround
The following steps should resolve the issue as a temporary work around until we have an update built into the SugarSync Manager.
In Finder, go to the Applications folder
Right click (or Ctrl click) on SugarSync Manager application
Select Show Package Contents
In the new Finder window that opens, go to Contents/Plugins and delete SugarSyncCMPlugin.cocoa.plugin.
After deleting these files, just restart Finder (or log out and log back in to your computer)
Note:  by deleting the plug-in you are disabling Finder extensions completely. You will lose overlay icons and context menus untill we fix the problem.  We apologize for the inconvenience and will get an update out as soon as possible.
Cheers
B

OS X 'Quick Look' stopped working