Will the DAO attacker be able to retrieve his funds on the 14th of july?

Question: It has been a month since the attack on the DAO. The attacker might be able to retrieve his/her stolen ETH in fiat currency tomorrow. Will (s)he be able to do so?
Comment: `@Cibils Thomas`, did you mean 14th of July in your title? I'm assuming so in the answer below.
Answer: From The big theDAO heist FAQ - Part II - The path forward:

Why is July 15 an important date for a hard fork? July 15 is NOT a hard deadline for a hard fork. However, July 15 is nevertheless an important date, because until then no Ether will have left any DAO. The creation period of the DAO started on May 1st. The creation period of the DAO took 27 days. Immediately after the creation period the first split proposal was made. This was executed after 7 days. Following this, a new DAO was created with another 27 day creation period. Finally another 14 days is required in the new split to make a proposal to send money out of the split. In total this is 75 days after theDAO started. So July 15 is the first possible date that ETH that was sent into the original DAO can be sent to regular accounts and mixed with ETH that is not involved with theDAO. Please note that the split that we are talking about is a regular split. The owner should be allowed to withdraw, however, to make the hard fork code as simple as possible it would be better to not have to deal with those exceptions.
The second important date is July 27. That is the first date where ETH could leave the darkDAO (hack on June 16 + 27 days creation period + 14 days proposal period).

From above:

15th July is the date that the early (non-malicious) splits can start withdrawing their ETH, making the accounting for the hard fork slightly more difficult.
27th July is the date when the attacker is first able to withdraw the ETH from The DAO. To convert the hot ETH into fiat currency, the attacker would have to take some precautions to hide the history of the hot ETH if selling on an exchange, or sell the ETH privately at a discount.

They will not be able to withdraw the hot ETH to their own account if the hard fork occurs. In this case, the modified Ethereum node software will transfer the attackers hot ETH into an account or contract out of reach from the attacker, for distribution back to the rightful owners.
If the hard fork is not accepted by consensus, the attacker will have some control of the hot ETH, but there is a friendly attacker that will try to attack the attacker's hot ETH using a similar attack to that originally used by the attacker. See link above for more details.


Copying Multiple Items / Sections in Cognito Forms

Question: When creating or editing a form, how can you copy multiple items/sections?
Answer: I am a developer for Cognito Forms.
First, if you are trying to capture the same information multiple times, you can use a Repeating Section, which is a section that the user filling out the form can repeat as necessary to enter the same information for a list of items, like players on a baseball team, employment history, medical conditions, etc.

Second, while you can only copy one thing at a time, you can place a number of items (including both fields and other sections) into a section, and then copy and paste the entire section and all of the items contained in the section will be copied as well.


What mechanism do I use for this pen-like design?

Question: I am trying to make a pen-like product that moves out fluid from its tip for some special chores, but I am having issues about the motion of the clutch. The picture you see is a sectioned concept because my thought isn't fully fleshed out.

Legend: Black stripes - fluid, Yellow - Button, Orange - Body, Pink - Spring, Teal - Clutch, Green - Clutch ring, Blue - Plunger, Red - Cap, Grey - Cartridge
Goal: When I push the button once, the plunger pushes up the red cap, which pushes up the fluid in the cartridge. As more liquid is expended, the red cap moves up until it reaches the top, when there's no liquid. Each time the button is pushed, I want the plunger to move and stop in accordance to the level of fluid left in the cartridge. For example, if the liquid is halfway, the plunger will be more upward.

I have a clutch system where the clutch ring is press fitted inside and a clutch has a tight fit against the clutch ring, to force the clutch to hold on to the plunger as it moves upward. This way, the plunger can move up then stay still without any external force acted on it (the button being pressed).

Main problem for me: After a certain level of fluid is gone but fluid still remains, the button won't be able to touch the plunger no matter how much I press the button. I tried introducing a small connection between the button and the clutch, so the plunger can still move even if the button doesn't have contact with it, but that introduces more problems.

You may notice more problems but the bottom line question is: will this mechanism work? If so, how can I resolve this main issue and if not, what other mechanism(s) will work? I'm not looking for specific numbers, but just needed to be point in the right direction (mechanism choice) to use.
I appreciate any and all responses!
Comment: Have you looked at how Sealent Guns achieve this same process?
Comment: Why not add a clutch inside the yellow part that allows you to push (but not pull) the blue plunger?
Comment: @JonathanRSwift No I haven't, but I'll definitely take a look at them. Can you expand on when you say add the clutch inside the yellow part to push and not pull? How can it be done correctly?
Answer: Take a look at a silicone gun mechanism. Simple and practical and does exactly what you are trying to invent.


Does "required reviews completed" mean good news or bad?

Question: I submitted by math paper to an Elsevier journal around 6 months ago. Today I logged into EES and saw that the status changed to "Required Reviews Completed" about 10 days ago. Is this good news or bad news ? Does it mean my paper is rejected and the Editor is basically preparing the rejection letter :( ?
Comment: Was it bad news in the end? :)
Comment: Found on Elsevier website. maybe useful for someone in the future.
In Editorial Manager (EM) a submission is considered ready for decision when a certain number of reviews have been completed, based on the article type and optionally customized by an editor. When a submission has reached the target number of completed reviews, or when a subordinate editor makes a decision ahead of that target:

The status changes to Required Reviews Completed.
Answer: It doesn't even necessarily mean that all reviews are completed. Sometimes editors invite more reviewers than is required. This message only means that the configured lower bound has been reached.
Comment: This is the right answer. Basically, it's neither good news nor bad news, it's no news, aka crappy user interface. One referee submitted their review, but probably more are needed, and there's no telling how much more time it may take.
Answer: You need to learn to have patience with the peer review process. It means neither good nor bad, just that the reviews are in. You can't see further into this hole than that.
Answer: This simply means the reviews are completed. It is not good news or bad news, it simply means the reviews are available to the editor. Hopefully you hear back soon, although frankly sometimes even at this stage it can take weeks (even months)!
Answer: I had the same question and I got in touch with the journal editorial office and got a quick reply saying:

Upon checking, I noticed that some reviewers have yet to submit their
  reviews. The status "Required Reviews Completed" shows when the
  required number of reviews is reached. Please note that the editor is
  still waiting for additional reports for your manuscript. Rest assured
  that you will be notified once updates are available.

So as others mentioned above, some reviews came through, maybe 2 as the minimum default on the system, and there still some to come so the editor is waiting to receive all prior to submitting a final verdict.
Answer: It means just what it says on the tin - that the required reviews are complete. It says nothing about their content, and whether a paper is accepted or not, it will likely come with a number of revisions and the like from reviewers. The editor needs to read the reviews, decide whether or not to accept the manuscript (and there are several different scales between just accept and reject), compile those comments into something coherent, etc.
The only thing you can divine from that message is that it wasn't rejected without review, which is also a potential outcome of a paper submission.
Answer: Based on my experience, it is a good news that you will be hearing soon from the editor regarding your paper (although you might hear a bad news).
In general, it is good to get an idea about the time frame for the journal your are submitting to. I use the Journal Finder from Elsevier (http://journalfinder.elsevier.com), which you can use to make a decision regarding the journal. This will show you the different times and acceptance rate.
Good luck!
Answer: I have got the same situation. I also submitted a math paper. This status implies that the referee have submitted his/her report. The handling editor then looks into it and make the next step: revise/final decision/reject.
In my case, I got this status two times. At the fist time, the handling editor required to revise the manuscript. And at the second time, the status changed to "decision in process".  Finally, my paper was accepted.
Answer: If you see this status after submitting the revision, it is definitely a good News.
If it is after the first submission, it means that you will received the comments from the reviewers! keep your belt fasten!


Finder in Snow Leopard Does Not Show All Files in Directory

Question: I have 1189 mp3 files in a single directory (Finder says I have 1189 files and Terminal reports 1189 files). The terminal command: "ls -1" (el es space dash one) shows the long list of files; they have numeric/alpha names that always sorts properly.  The problem is in the Finder listing; When I scroll through this very large directory (regardless of display mode - list, column, or cover flow) there are gaps in the files displayed (remember they are sequential and finder SHOULD sort them the same as terminal)  Though my research it appears that the finder listing is limited to about 1024 entries. I don't know if this also applies to any previous OS X releases.  Is there a way to tell Finder to display more (all) files?
Answer: Finder does not sort files the same as the terminal.
The terminal (or more correctly, ls), sorts using simple ASCII ordering. The Finder uses the Unicode Collation Algorithm - see this Apple Support article
BTW, I managed to create a folder with > 100,000 files and Finder displayed all files.


Why is making a white laser so difficult?

Question: There are red, green, and blue lasers out there but i can't find a white laser? how hard is to make one? Is it possible?
Comment: [Cross-posted to Physics](https://physics.stackexchange.com/q/415429/44126).
Answer: Its not hard- it bends the idea of what a laser is. Lasers have a single (or very narrow) wavelength of light emitted. There is no "white" wavelength- its just what your eye perceives from a (relatively) full spectrum of wavelengths.
This is generally considered by the scientific community to be an advantage, not a disadvantage. You can do many cool things with a single wavelength that you can't do with a broad spectrum.
You could potentially make a white-ish laser by syncing up many different lasers to make a combination beam that your eye perceives as white. This would be a very difficult engineering problem though, if you actually wanted a spatially coherent laser. Thanks to OpticalResonator for pointing out some folks who managed to do it in a single crystal, which is pretty wild.
Comment: It has actually been done in 2015, see this paper https://www.nature.com/articles/nnano.2015.149
Comment: Whoa, cool! I considered that possibility but omitted it because I wasn't sure it would even count as a laser since it doesn't make any sense for it to be temporally coherent. Do they address that point in the full text (I'm stuck on the paywall)?
Comment: I'm sadly also stuck there :P it does come from one single laser active medium, with 3 layers that emit on 3 wavelengths, so I would assume that it is coherent
Comment: *Some* lasers have a narrow frequency spectrum in their emissions; other lasers (typically used for pulsed emission) emit over extremely broad spectra that can span close to an octave. Narrow-band emission can seem like the entirety of laser science for people who work with CW lasers, but it is not the only useful mode of operation.


What are effective ways to prevent targeted phishing?

Question: Phishing is a very serious problem that we face. Popular banks are often the biggest targets.  What methods can a bank website use to protect its self from phishing attacks? What security systems should someone use to protect themselves?   Why do these methods work?
Comment: I'm not sure one can protect against users on auto-pilot.
Answer: I am assuming that the bank wants to protect its customers from phishing.  (Not its employees; that's a different problem, and if you want to know about that, you should ask that one separately in a different question.)
The bank should take several steps:

Avoid emailing out links to the site.  Go clobber the marketing team and get them to quit doing that.
Don't rely too much on passwords.  Use machine authentication, too.  For instance, you might use a secure persistent cookie, a Flash cookie, or some kind of fingerprinting of the user's browser and machine.  Passwords are inherently insecure against phishing.  The advantage of machine registration is that it authenticates the user's browser with a secret the user doesn't know.  If the user doesn't know the secret, the user can't be tricked into revealing it.  With the combination of machine authentication plus a password, the machine authentication does most of the authentication work, and the password just enables one to distinguish between the user and their roommate/spouse/child/etc.

Don't rely upon challenge questions to authenticate the user when the user logs in from a new computer.  Studies have shown that phishing sites can capture the answers to challenge questions, just like they do passwords.  Consider other methods of registering a new machine, e.g., email-based authentication.

Use back-end fraud detection methods, to detect malicious use of a stolen password.  You can look at whether this is a type of transaction the user has performed before, to a payee they have transacted with before, whether the amount is large or not, whether the user IP address and geographic location and browser fingerprinting looks like one that has been seen before, and many other statistical measures.
Participate in anti-phishing working groups.  Work to take down phishing sites quickly.  Support use of phishing blacklists in users' browser.  If a user logs in with a browser that is so old that it doesn't support a phishing blacklist, give the user a message that encourages them to upgrade their browser and gives them an easy link to do so.

Participate in anti-fraud working groups, and pressure the banking community to shut down global banks that facilitate online crime.  A recent study found that just 3 banks accounted for monetization of 95% of spam; if those 3 banks were shut down or cracked down on spammers, we might see a huge decrease in spam.  There is reason to believe that a similar phenomenom may hold for other elements of the underground economy, too.  Making cybercrime less profitable will benefit bank security across the board (not just in phishing), so is a promising angle.

Use site-wide SSL for the entire site and your entire online presence.  Buy an EV cert.  This gives users an extra cue (the green glow) that may help some alert users notice when they are under attack.
Enable Strict Transport Security (HSTS).  This tells browsers to only connect to you via HTTPS.  Paypal uses it.  You should too.  It is supported in recent versions of Firefox and Chrome.
Don't put padlock icons on your pages (e.g., positioned next to login forms), or otherwise spoof chrome elements in the content of your page.  When you do that, you are training users in a way that makes phishing attacks easier.
Digitally sign all email sent to customers.  There is some reason to believe that most customers have software that can check these signatures, and the signatures won't cause problems for the software that doesn't check the signature.  (Thanks to @AviD for this suggestion.)
Don't use SSNs for authentication anywhere in your business.  Make it less valuable for phishers to steal SSNs and other personal information.
Comment: Nice list.  It would help to separate out those suggestions that help individual banks from those that really need wider support from the industry before most individuals learn to be suspicious of the practice in general.  E.g. if a user's last bank frequently sent out links to their site, or challenged the user for their security questions, the user will probably still be susceptible to such attacks even if their new bank rarely does either.
Comment: Very nice. One addition / change I would make, wrt emails they send out - digitally signed emails are well supported by almost all current email clients, no reason not to use them.
Answer: This is what i'd do:

have a team of security staff to ensure all software is up to date/patched and configured correctly (the size of this team depends on the size of the organisation)
do not allow any employee access to anything remotely dangerous unless they need it
for those employees who do need access, think about exactly what they need (eg: in a bank, do not allow a low level employee to make transactions involving large amounts of money)
do not give anyone who's technologically challenged access. Fire or train existing employees if you must
if someone important like your CEO/executive is challenged, don't give him access to the network - make all his actions go through someone who understands basic security
keep good logs of every important event on the network, it will be helpful when trying to minimise damages after a successful attack occurs

With regard to training employees about security, just asking them to read white-papers is not enough. You need to really teach them the basics of how a hacker gains access to a network, and if they don't or are unable to learn it then you should either fire them, or take away their access to anything that needs security.
Answer: The solution to phishing is most basic: Use strong mutual authentication. Cleartext passwords over unilaterally authenticated SSL do not provide this. Essentially, phishing detaches the two authentication steps, thus breaking the mutual authentication.
A simple improvement can be secure password-based authentication using PAKE protocols, such as SRP.
Another improvement that also tackles most social engineering-based attacks is to use multi-factor authentication: You can call someone and convince them to give them your secret, but try telling them to also send them their USB token. This is much harder, it does not scale well, and is more risky due to physical interaction with the victim. It is also harder for social engineering since it is not a simple spontaneous action for the victim and it feels very wrong to remove that token from your key chain and send it somewhere.
What is left then is that people try stealing personal data and credit card info. What is needed here are proper identity identicators on the client side ("This website is bank.com"), secure payment systems and most importantly common sense.
So, why is nobody doing that? People say cost and usability is the problem. But most financial institutions noticed by now that multi-factor is needed, although they tend to deploy incompatible and often vulnerable solutions. The Web crowd also finally noticed that passwords don't really scale well, so now we got password managers and federal ID. The first has rather similar restrictions as a proper smartcard-based solutions and the second one is still vulnerable. The problem is, people don't like PKI. It's too complex, too unfamiliar, even though IE and Firefox have pretty good support by now. We need systems like Skype and Jabber, where the PKI is silently bootstrapped in the background and authorization is basically done with key continuity management. And replace X509 with SPKI, to reduce procedural and implementation bugs.
Answer: Really, the best defence is awareness training - it has some effect but is by no means foolproof. The two big problems are:
1 - end users forget their teaching and still click on links
2 - some banks still have marketing teams who send out emails with links
The bigger global banks have got very good at phishing site takedowns, so at least this forces the attackers to use a lot more effort to get phish attacks out.
Have a look at this previous question on phishing for some more info.
update Targeted phishing, or spearfishing, is a very successful tactic for attackers, as they personalise the emails to such a level that most individuals believe they are from a trusted source. Currently the effort involved means it is still the higher value targets that are attacked, however attacks such as the recent PSN hack have provided attackers with useful information to carry out this attack on a large scale.
Comment: Awareness training has been shown in the literature multiple times to not work. I do not suggest spending money on this -- and if a regulatory standard or compliance initiative suggest that budget be placed in this area, then I would ignore the advice and seek compensating or alternate controls.
Comment: "But but but ... I didn't click on any phishing e-mails, I just wanted to see the dancing hampsters, and it looked safe, it was From: my buddy Joe in the next cubicle, and he wouldn't do that!" I have yet to see a different reaction from a phished user, trainings or no trainings. Users will do *anything* to see hampsters; if the malware wanted them to compile a kernel and put it on a bootable USB stick, I'm convinced they'd do it, even when they otherwise can't learn to print from the default printer. (Bitter? Me? BTW *proved* - do you have a link to a study, or is it not public?)
Comment: @Piskvor - you get a plus one just for the hamsters. Did you see the recent Facebook phish that actually required users to copy and paste javascript into their browser bar? The study was actually internal with a couple of our clients - global banks - and it came out with some lovely graphs of stupidity/time showing the impact of various types of activity. tl;dr repeating the same type of training had lower effect every time, but varying online, video, roleplay, classroom etc worked pretty well.
Comment: Yup, that's exactly what I mean; next station: bookmarklets (only one browser warning dialog, and no keyboard interaction required). Thankfully, IE9 and NoScript for FF have mitigation measures (see @EricLaw's blog: http://blogs.msdn.com/b/ieinternals/archive/2011/05/19/socially-engineered-xss-attacks-and-pasting-javascript-in-the-address-bar-in-ie9.aspx ). A graph of stupidity over time, that sure is interesting :D Pity it's not available; oh well.
Comment: Actually it does work pretty well, and we've proved that, but not for long periods, and you can't use the same training over again - it just gets ignored.
Answer: I do not believe that awareness training works.
The best way to combat phishing is to whitelist email addresses and web application content/behavior that can be accessed by users.
There are many ways to stop phishing that uses malware. What kind of phishing attacks are you interested in and maybe I can provide some additional advice?
Answer: On top of the suggestions given, I would also suggest getting help from MSS providers. There are few MSS providers out there that provides subscription based service that helps organization detect phishing and brand name abuse online.
An extra eye would definitely be helpful in cases like these.


Loadmodule with parameters

Question: How can i effectively add a custom parameter for the function {loadmodule mod_name}. Something like:
{loadmodule mod_video_player src="0Bmhjf0rKe8" start="5" end="20"}
Any ideas? Thanks!
Answer: Don't use loadmodule actually. You have to make your own plugin based on it.
Copy the loadmodule plugin from plugins/content/loadmodule to another folder (probably plugins/content/video_player based on your question). We will use it as a base, but change how it loads things.
I would then trigger the module with code like the following:
{video_player src="0Bmhjf0rKe8" start="5" end="20"}

You would then need to adjust the regex (and remove one, since you only have one trigger) to be like so:
// Expression to search for(modules)
$regexmod   = '/{video_player\s(.*?)}/i';
$stylemod   = $this->params->def('style', 'none');

Finally, you would need to adjust all of the processing (and this part is on you to try) so that it processes the matching string (which will be all your settings) and returns a video player with those settings, like how the current plugin returns the loaded module.
You can either actually load the module and pass it settings or place the code for the video player in the plugin.
Answer: If you are not a developer to make your own plugin then its best to use nonumber, really simplifies things like this.
http://www.nonumber.nl/extensions/modulesanywhere/userguide
It is a pro only feature but it allows you to adjust settings.

Loadmodule with parameters


Isomorphic algebras determine diffeomorphic manifolds

Question: It is a kind of folklore but I would like to see the proof of the following fact: given two smooth manifolds $M$ and $N$ if we assume that the algebras $C^{\infty}_0(M)$ and $C^{\infty}_0(N)$ are isomorphic (as algebras) then $M$ and $N$ are diffeomorphic.
Answer: Theorem 2.8 on p. 30 of Models for smooth infinitesimal analysis by Moerdijk and Reyes.  The theorem works with $C^\infty$ rings, which are a bit more general than algebras of functions.  The advantage is that the proof is short.
Comment: I don't know a direct proof.   My answer slyly suggested that looking at the algebra of functions on a smooth manifold as an algebra is a bit silly and that $C^\infty$ rings provide a better framework.   But since I cheated, here is an answer to the question you asked:   Theorem 2.3 on p. 34 of  *$C^\infty$-Differentiable Spaces*  by Juan A. Navarro Gonzalez and Juan B. Sancho de Salas (Springer LNM 1824).
Comment: I have already accepted your answer, however I realized that there is one subtle thing.
As you mentioned the notion of $C^{\infty}$ ring is more general than just smooth functions
on manifold however the notion of _morphism_ in this category appears to be more restrictive.
So how one can prove that any homomorphism
of algebras is automatically a $C^{\infty}$ morphism (as defined in Moerdijk's book)?


21 hours layover at Tokyo Narita

Question: I have Indian passport and US visa. How easy/difficult is it to get the transit pass for a day to visit Tokyo. How much does it cost? Can it be done online or at the airport upon arrival. Is it 24 hours counter? I will be traveling with 2 children.
Comment: It's called a shore pass and is issued to nationals not eligible to enter visa-free. It's valid for 72 hours and is issued if the passenger holds an onward ticket to a third Country AND there are no departures on the same day
Comment: What is this "transit pass" you speak of?
Answer: As India is not on Japan's Visa Waiver List you should be able to get a Shore Pass/Transit Pass however this is not guaranteed (as we don't know your particular circumstances) and you may be refused boarding by the airline in some cases.
Japan has the following (taken from Qatar Airways Visa Check Portal)
TWOV (Transit Without Visa):

Holders of onward tickets transiting to a third country can obtain a Shore Pass/Transit Pass on arrival for a max. stay of 72 hours only if there are no connecting flights on the same calendar day and if:

holding a passport, proof of maintenance during their stay, and sufficient evidence that Shore/Transit Pass will be appropriately used; and

departing from the same airport of arrival, or from a different airport (or seaport) around the airport (or seaport) of arrival, if both ports are located within the same group.

Somewhat confusingly, the Japanese Embassy in India website mentions that you will need to apply for a transit visa in advance.
Failure to have a valid transit visa (as your trip is 21 hours long and Narita Airport does close), you may be denied boarding as has happened to some people.
You should check with the Japanese Embassy closest to you as your personal circumstances determine your validity for the transit visa and there is not a guarantee of you receiving a transit visa in all cases.
Comment: You say **will not** with certainty. If he is on a Japanese watch list, has previous convictions within Japan, has convictions with a country Japan shares information with (ie. US) has something on his person that is found and is deemed illegal (anything with Ibuprofen) etc. He may be warned and either allowed through with a record kept of the infraction, detained or deported, regardless of the status of any ongoing flights. And as I linked to he **may** be denied boarding at the airlines prerogative. Further, failing any of the above points (in my answer) will mean a refused shore leave pass.
Comment: He **will not** be denied Boarding. The Airlines go by Timatic (what you just outlined), end of Story. He said himself he'll be travelling to/from NRT (same Airport, therefore same class), thus he is eligible if there are no connecting flights to his Destination on the same day
Comment: Nevertheless, OP, **if** there should be issues at check-in, ask them to look up Timatic (the Name of the database) and put Japan as the Transit Country. Tell them you're travelling under the Shore pass arrangement
Answer: You get it on Arrival, however it's only issued if there are no connecting flights to your destination on the same calendar day. It's valid for 72 hours.
At Immigration, Show your onward ticket and passport

21 hours layover at Tokyo Narita


Scared of praying because of fear of death

Question: Due to having some anxiety issues and being scared too easily, once I heard a man who died while praying jumah after which I became frightened even though death is a gift towards a new life. I am scared maybe because my imam is weak. Please give me the confidence to pray again through your advice. Whenever I try praying, I always get these evil thoughts so I can't continue and stop and cry.
Comment: Salam and welcome to IslamSE the Q&A site about Islam. To learn more about our site and model consider taking our [tour] and checking our [help].
Answer: Everybody knows they are going to die one day, but they choose to ignore the fact. It's good that you acknowledge the fact and always remember that. However knowing this fact brings a question, "If it's inevitable, what can I do to make it worth dying ?" and the answer is to live a righteous and meaningful life. There is not greater meaning than worshiping the one who created you and the one whom you will return. The Best form of death is passing away while you are in the middle of this act.
Think about the real meaning of life brother and remember it's just the deception of the devil. If you know all these facts there is no reason for you to be scared. If you are scared because of your sins, take action and pray more for the mercy of Allah. Allah is the most merciful.
Allah knows the best !
Answer: Assalam-u-Alaikum
Brother these are waswas from shaitan don't  listen to these thoughts ALLAH has already decreed the time for your death when you were not even born.Nothing will happen to you until ALLAH wills.Just put your trust in ALLAH


is it possible to use near beer as my wort and add brewers yeast to have beer with %5-6 ABV?

Question: Good day to everyone in here! This is my first post and I'm a newbie in here , and I would like to ask you guys if I can use non alcoholic beer ( near beer) as my wort + brewer yeast ( not bread yeast) to get %5-6 ABV ? The reason is because in where I'm living its almost impossible to get malt extract and the only barely malt extract I found in one market it costs 50$ per 1 LBs which is very expensive , that's why I'm wondering if I can use the near beer as a substitute, thanks a lot and best regards!
Answer: There is nothing to ferment in near beer. It is not a sweet malty beverage normally.  Adding yeast to it won't give you anymore alcohol.
You could add sugar or some other malt beverage (e.g. Malta-Goya) and ferment that but, this isn't going to generate a beer in the sense that you are thinking.
Perhaps wine or mead making is better suited to your area as those starting materials are often a bit more universal.
Answer: You can always try making "syntha-beer". Alcohol and carbon dioxide come from fermenting sugars (like glucose or sucrose) . Sugars are usually relatively easy to obtain. So fermenting a solution of sugar with yeast will yeild a base fizzy alcoholic brew. If you want to make it more "malty" try adding "ovalteen" malt drink powder. If you want to make it "thicker" with more turbidity then use maltodextrin (commonly available as a body building additive).
Next comes flavouring and colouring which usually comes from hops and some aspect of roast grain. Presuming one can obtain hops, it is simplest to boil them in water to make "hop tea" and strain that into the brew. The next thing is to find some roast grain like a crystal, chocolate or roast malt. Dark roast barley is sometimes sold as an alternative to decaf coffee. If all else fails use raw barley grains or raw wheat grains and roast them on a tray in an oven until they turn brown to the desired degree. Crack/crush the roast grain, steep in boiled water for (say) 30 mins and strain the brown liquid into your fermentation bin with the sugars, maltodextrin and hop tea.
It might not be the same as a pint of "Courage Best" but in a hot country far from the homebrew shop - served cold and fizzy it can taste like nectar - and gives a cracking hangover!
Comment: It was developed for/with a friend who lived in "a hot country with no home brew shops". He looked in the local stores for what he could get and the only thing he had to "import" were the hops. The name "syntha beer" is mine after a project I had trying to make a clone of "Bud-Lite" using only glucose, maltodextrin, hop essence and caramel/colouring. I am aghast to say the results were unnervingly accurate! I have a particular fascination for brewing "beer" from improbable ingredients in unheard of locations.  ...but I brew the real stuff too. 12 pints of that can give me a hangover as well!
Comment: Is "syntha-beer" a reference from something?  Fascinating advise, I almost want to try it, except the cracking hangover.  Did you come up with this recipe or speak from experience?  Highly creative nonetheless, a step up from pruno.
Answer: To answer the original question. Absolutely. If you live somewhere where there is no beer available, but there is a quality near beer such as Holsten or Becks, you can make a quality beer.
Recipe:
5 gallon plastic water jug,
16 liters of holsten(48 x 355ml)
1-1.5 kg of light brown sugar,
1 pack of Nottingham or Windsor yeast,
Stopper at the top of jug to allow fermentation,
Wait 1-2 weeks,
Rack or transfer from original jug to secondary clean jug leaving yeast residue behind.
Add 1cup white sugar and mix well to prime and restore carbonation,
Bottle in ikea resealable bottles,
Wait 3 weeks,
Fantastic beer - better than cheap store bought beer because of the natural carbonation and full bodied flavors that comes from Holsten which starts out as a quality regular beer but the alcohol is removed. and the cost is less than a buck a beer.
My experience is 12 years of approx. 1500 to 2000 beers/year


What are my best options if I don't have a lot of credit lines for housing loans?

Question: I've been denied for a pre qualify loan by Bank of America for a house recently due to having insufficient credit lines. I do have a credit score that is good and everything else is fine. I think it is a bit silly to be denied just because of insufficient credit lines. Is there something I can do? I don't have enough traditional credit lines right now either. This is very frustrating, but there has to be a way around this. Any tips or suggestions are appreciated. I'm thinking about using FHA.
Comment: Renting while you save more money toward the down payment and build a good credit history is not at all unreasonable. Buying is not always better financially, not is it "more adult".
Answer: Rather than trying to indirectly game your credit score, I would instead shop around and see if there are other lenders that will pre-qualify you with your credit the way it is today.  BofA and other large banks can be very formulaic in how they qualify loans; a local bank or credit union may be more willing to bend the traditional "rules" and pre-qualify you.

I'm thinking about using FHA.

If you can put 20% down then a conventional mortgage will likely be cheaper than an FHA loan since FHA loans have mortgage insurance built-in while conventional mortgages typically don't require it if you borrow less than 80% of the house's value.  I would shop around before jumping to an FHA loan.
Answer: The short answer is, with limited credit, your best bet might be an FHA loan for first time buyers.  They only require 3.5% down (if I recall the number right), and you can qualify for their loan programs with a credit score as low as 580.
The problem is that even if you were to add new credit lines (such as signing up for new credit cards, etc.), they still take time to have a positive effect on your credit.  First, your score takes a bit of a hit with each new hard inquiry by a prospective creditor, then your score will dip slightly when a new credit account is first added.
While your credit score will improve somewhat within a few months of adding new credit and you begin to show payment history on those accounts, your average age of accounts needs to be two years or older for the best effect, assuming you're making all of the payments on time.
A good happy medium is to have between 7 and 10 credit lines on your credit history, and to make sure it's a mix of account types, such as store cards, installment loans, and credit cards, to show that you can handle various types of credit.
Be careful not to add TOO much credit, because it affects your debt-to-income ratio, and that will have a negative effect on your ability to obtain mortgage financing.
I really suggest that you look at some of the sites which offer free credit scores, because some of them provide great advice and tips on how to achieve what you're trying to do.  They also offer credit score simulators, which can help you understand how your score might change if, for instance, you add new credit cards, pay off existing cards, or take on installment loans.  It's well worth checking out.
I hope this helps.  Good luck!


Frontend Cannot login after SSL installed

Question: We installed SSL and got the https:// working on our magento 1.9.2 site however we can only login once when we clear our cookies. We can not logout and then log back in again...When we press login it just goes back to the same login page again...unless we clear our cookies and reset the browser.   We tried adding the form_key after  to both the customer and peristent login files but its still not working. Does anyone have any ideas?
Comment: see here http://magento.stackexchange.com/a/93406/21339
Answer: try this code frinds:-
Magento 1.9 has been used form key validation at customer loggin and register page.On Post action it check the form key using function _validateFormKey() at controller
form key  issue: form key missing so add this code in your form
<input name="form_key" type="hidden" value="<?php echo Mage::getSingleton('core/session')->getFormKey() ?>" />

OR
Cookie domain setting issue goto check setting is proper or not
at Admin>System>configuration>General>Web>Session Cookie Management
Comment: Hello we have tried the formkey solution. Is our Session Cookie Management setting correct?


Definition of "downstream" and "upstream"

Question: I've started playing with Git and have come across the terms "upstream" and "downstream".  I've seen these before but never understood them fully.  What do these terms mean in the context of SCMs (Software Configuration Management tools) and source code?
Comment: There are two different contexts for upstream/downstream in git: remotes, and time/history. Upstream/downstream with respect to remotes is, the downstream repo will be pulling from the upstream repo (changes will flow downstream naturally). Upstream/downstream with respect to time/history can be confusing, because upstream in time means downstream in history, and vice-versa (genealogy terminology works much better here - parent/ancestor/child/descendant).
Comment: Related: [What does 'upstream' mean?](http://opensource.stackexchange.com/q/993/407) at OS
Comment: Related: [Difference between origin and upstream](https://stackoverflow.com/q/9257533/465053) on gitHub
Answer: In terms of source control, you're downstream when you copy (clone, checkout, etc) from a repository. Information flowed "downstream" to you.
When you make changes, you usually want to send them back "upstream" so they make it into that repository so that everyone pulling from the same source is working with all the same changes. This is mostly a social issue of how everyone can coordinate their work rather than a technical requirement of source control. You want to get your changes into the main project so you're not tracking divergent lines of development.
Sometimes you'll read about package or release managers (the people, not the tool) talking about submitting changes to "upstream". That usually means they had to adjust the original sources so they could create a package for their system. They don't want to keep making those changes, so if they send them "upstream" to the original source, they shouldn't have to deal with the same issue in the next release.
Comment: "Download" and "upload" are verbs. "Upstream" and "downstream" describe a relative position.
Comment: They are adjectives when they are used as modifiers, but those terms are often used as nouns.
Comment: I would say upstream and downstream are adjectives
Comment: @MycrofD words can be used as adjectives and nouns depending on the context
Comment: When "upstream" and "downstream" describe a relative position, I think, technically, that makes them adjectives. This is just a comment on what I understand, not correcting anyone.
Comment: In fact, "upstream" and "downstream" can be used not only as adjectives ("an upstream repository") or nouns ("I don't care about the downstream"), but as adverbs (as in "that repository is upstream of mine" or "everything you need is already downstream").
Comment: Let us ask in https://english.stackexchange.com/. whether it is noun or adj. or adv :D
Comment: @NusratNuriyev, let's consider "preposition" while we're at it : )
Answer: When you read in git tag man page:

One important aspect of git is it is distributed, and being distributed largely means there is no inherent "upstream" or "downstream" in the system.

, that simply means there is no absolute upstream repo or downstream repo.
Those notions are always relative between two repos and depends on the way data flows:
If "yourRepo" has declared "otherRepo" as a remote one, then:

you are pulling from upstream "otherRepo" ("otherRepo" is "upstream from you", and you are "downstream for otherRepo").
you are pushing to upstream ("otherRepo" is still "upstream", where the information now goes back to).

Note the "from" and "for": you are not just "downstream", you are "downstream from/for", hence the relative aspect.

The DVCS (Distributed Version Control System) twist is: you have no idea what downstream actually is, beside your own repo relative to the remote repos you have declared.

you know what upstream is (the repos you are pulling from or pushing to)
you don't know what downstream is made of (the other repos pulling from or pushing to your repo).

Basically:
In term of "flow of data", your repo is at the bottom ("downstream") of a flow coming from upstream repos ("pull from") and going back to (the same or other) upstream repos ("push to").

You can see an illustration in the git-rebase man page with the paragraph "RECOVERING FROM UPSTREAM REBASE":
It means you are pulling from an "upstream" repo where a rebase took place, and you (the "downstream" repo) is stuck with the consequence (lots of duplicate commits, because the branch rebased upstream recreated the commits of the same branch you have locally).
That is bad because for one "upstream" repo, there can be many downstream repos (i.e. repos pulling from the upstream one, with the rebased branch), all of them having potentially to deal with the duplicate commits.
Again, with the "flow of data" analogy, in a DVCS, one bad command "upstream" can have a "ripple effect" downstream.

Note: this is not limited to data.
It also applies to parameters, as git commands (like the "porcelain" ones) often call internally other git commands (the "plumbing" ones). See rev-parse man page:

Many git porcelainish commands take mixture of flags (i.e. parameters that begin with a dash '-') and parameters meant for the underlying git rev-list command they use internally and flags and parameters for the other commands they use downstream of git rev-list. This command is used to distinguish between them.
Comment: you *pull from* upstream, and you *push to* upstream. pushing to downstream sounds very wrong to me
Comment: @knittl: you are right. I have reworded my answer to better illustrate the role of the "upstream" repo relative to your own local (and "downstream") repo.
Answer: Upstream (as related to) Tracking
The term upstream also has some unambiguous meaning as comes to the suite of GIT tools, especially relative to tracking
For example :

   $git rev-list --count --left-right "@{upstream}"...HEAD
   >4   12

will print (the last cached value of) the number of commits behind (left) and ahead (right) of your current working branch, relative to the (if any) currently tracking remote branch for this local branch. It will print an error message otherwise:
    >error: No upstream branch found for ''

As has already been said, you may have any number of remotes for one local repository, for example, if you fork a repository from github, then issue a 'pull request', you most certainly have at least two: origin (your forked repo on github) and upstream (the repo on github you forked from). Those are just interchangeable names, only the 'git@...' url identifies them.

Your .git/configreads :
   [remote "origin"]
       fetch = +refs/heads/*:refs/remotes/origin/*
       url = firstname.lastname@example.com:myusername/reponame.git
   [remote "upstream"]
       fetch = +refs/heads/*:refs/remotes/upstream/*
       url = email@example.com:authorname/reponame.git

On the other hand, @{upstream}'s meaning for GIT is unique :

it is 'the branch' (if any) on 'said remote', which is tracking the 'current branch' on your 'local repository'.
It's the branch you fetch/pull from whenever you issue a plain git fetch/git pull, without arguments.

Let's say want to set the remote branch origin/master to be the tracking branch for the local master branch you've checked out. Just issue :

   $ git branch --set-upstream  master origin/master
   > Branch master set up to track remote branch master from origin.

This adds 2 parameters in .git/config :
   [branch "master"]
       remote = origin
       merge = refs/heads/master

now try (provided 'upstream' remote has a 'dev' branch)
   $ git branch --set-upstream  master upstream/dev
   > Branch master set up to track remote branch dev from upstream.

.git/config now reads:
   [branch "master"]
       remote = upstream
       merge = refs/heads/dev

git-push(1) Manual Page :
   -u
   --set-upstream

For every branch that is up to date or successfully pushed, add upstream (tracking) reference, used by argument-less git-pull(1) and other commands. For more information, see branch.<name>.merge in git-config(1).
git-config(1) Manual Page :
   branch.<name>.merge

Defines, together with branch.<name>.remote, the upstream branch for the given branch. It tells git fetch/git pull/git rebase which branch to merge and can also affect git push (see push.default).
  \
  (...)
   branch.<name>.remote

When in branch < name >, it tells git fetch and git push which remote to fetch from/push to. It defaults to origin if no remote is configured. origin is also used if you are not on any branch.

Upstream and Push (Gotcha)
take a look at git-config(1) Manual Page

   git config --global push.default upstream
   git config --global push.default tracking  (deprecated)

This is to prevent accidental pushes to branches which you're not ready to push yet.
Comment: Excerpt of `git branch --help` as of 2018: `As this option had confusing syntax, it is no longer supported. Please use --track or --set-upstream-to instead.`
Answer: That's a bit of informal terminology.
As far as Git is concerned, every other repository is just a remote.
Generally speaking, upstream is where you cloned from (the origin). Downstream is any project that integrates your work with other works.
The terms are not restricted to Git repositories.
For instance, Ubuntu is a Debian derivative, so Debian is upstream for Ubuntu.
Answer: Upstream Called Harmful
There is, alas, another use of "upstream" that the other answers here are not getting at, namely to refer to the parent-child relationship of commits within a repo. Scott Chacon in the Pro Git book is particularly prone to this, and the results are unfortunate. Do not imitate this way of speaking.
For example, he says of a merge resulting a fast-forward that this happens because

the commit pointed to by the branch you merged in was directly
  upstream of the commit you're on

He wants to say that commit B is the only child of the only child of ... of the only child of commit A, so to merge B into A it is sufficient to move the ref A to point to commit B. Why this direction should be called "upstream" rather than "downstream", or why the geometry of such a pure straight-line graph should be described "directly upstream", is completely unclear and probably arbitrary. (The man page for git-merge does a far better job of explaining this relationship when it says that "the current branch head is an ancestor of the named commit." That is the sort of thing Chacon should have said.)
Indeed, Chacon himself appears to use "downstream" later to mean exactly the same thing, when he speaks of rewriting all child commits of a deleted commit:

You must rewrite all the commits downstream from 6df76 to fully remove
  this file from your Git history

Basically he seems not to have any clear idea what he means by "upstream" and "downstream" when referring to the history of commits over time. This use is informal, then, and not to be encouraged, as it is just confusing.
It is perfectly clear that every commit (except one) has at least one parent, and that parents of parents are thus ancestors; and in the other direction, commits have children and descendants. That's accepted terminology, and describes the directionality of the graph unambiguously, so that's the way to talk when you want to describe how commits relate to one another within the graph geometry of a repo. Do not use "upstream" or "downstream" loosely in this situation.
[Additional note: I've been thinking about the relationship between the first Chacon sentence I cite above and the git-merge man page, and it occurs to me that the former may be based on a misunderstanding of the latter. The man page does go on to describe a situation where the use of "upstream" is legitimate: fast-forwarding often happens when "you are tracking an upstream repository, you have committed no local changes, and now you want to update to a newer upstream revision." So perhaps Chacon used "upstream" because he saw it here in the man page. But in the man page there is a remote repository; there is no remote repository in Chacon's cited example of fast-forwarding, just a couple of locally created branches.]
Comment: The git-rebase man page also suffers from this overloading: the commit that is checked out before rebasing is termed the "upstream". This, too, may have affected Chacon's usage.
Comment: Good point. Would be kind of helpful to gather common "git-terminology" somewhere. Especially for newbies ( or ppl contributing to git ). Would have saved me good time getting used to the wording of the git man pages.
Comment: Came here from the `git-rebase` docs because I was totally confused why a commit ref would be called "upstream" there (in fact, I was doubting myself as I haven't seen this terminology before). Thanks @outis & @matt for clearing things up!
Comment: @outis strange - in the git html documentation, the branch checked out before rebasing is referred to as ``.
Comment: git-scm docs/ref/book is actively harmful to understanding what are already questionable design decisions (e.g. overloaded methods, inconsistent syntax).
Answer: Using the analogy of a river, we can follow a resource upstream from us until we find the headwaters (the source of a stream or river).
Continuing with the river analogy, downstream is the direction that the water in a river flows. Downhill.
So, if I fork someone's project, The project I forked is upstream. And my fork is downstream.
if someone forks my forked project, Then my fork becomes upstream relative to the fork of my project.
And the fork of my fork becomes downstream.
Example Time!

Suppose Project B forked Project A and Project C forked Project B.
Then, Project A is the upstream project.
Project B is the downstream project relative to Project A.
Project B is the upstream project relative to Project C.
Project C is the downstream project relative to Project B.
And the circle of life continues.
NOTE: Please note that, this is a rather common development style in open source projects to create a fork of a project, fix a bug or add a feature in that fork and then submit a patch to the original project.
Also note that, a clear lesson from the "quality movement" and statistical process control is that interventions that fix quality problems at their source are almost always a better investment than repeated work to fix problems that were preventable. So please contribute patches (send Pull requests).


Removing Sile Stone Countertop

Question: I am in the process of having some counters replaced.  Any suggestions on how to remove the Sile Stone without damaging the cabinet?  Trying to determine if the extra cost of demolition is worth it.
Comment: I would presume that, like most countertops, it is secured from underneath...
Answer:
Score the caulk underneath the cabinet that runs along the cabinet frame. If sections of the countertop have been joined with silicone, make note of their position. Use caution lifting the countertop at these sections.
Pry the countertop loose with the pry bar and hammer. If you run into caulk or epoxy seam that's difficult to break loose, don't use excess force. Instead, use a utility knife to score the caulk or seam until you can safely use the pry bar. Continue prying the front of the countertop loose along its length.
Lift the front of the countertop as you side a furring strip between the countertop and cabinet, as close to the back as you can go. Lower the countertop onto the furring strip.
Push the front of the countertop down, breaking the caulk seal at the back of the countertop. If necessary, go under the cabinet and pry between the wall and the back of the countertop while a helper pushes down on the front. Gently lift the countertop off the cabinet and set it aside.
Answer: Silestone is glued to the top of the cabinet. Depending on how much adhesive and the type used it may be very difficult to remove. No mounting hardware on the ones I have helped install (only 2 with the same contractor).

Removing Sile Stone Countertop


9th planet location?

Question: I've seen a number of news reports indicating there is likely a 9th planet in our Solar System, something with an orbital period of between 10k-20k years, that is 10 times Earth's mass. I haven't seen any real indication of where this object might be. If I had access to a sufficient telescope, would I be able to find this planet, and what way would I point a telescope to find it? How far is it likely to be, or is that not well known?
Comment: No-no, the question is valid. The hypothetical planet was inferred from its influence on other bodies. It could be conceivable that, from this very influence, the position of P9 within it's orbit is computable (with one or more solutions for the equation). So: where is it???
Answer: It's too dim to be seen during a normal survey during the majority of its
orbit.
Update:  Scientists at the University of Bern have modeled a hypothetical 10 Earth mass planet in the proposed orbit to estimate its detectability with more precision than my attempt below.
The takeaway is that NASAs WISE mission would have probably spotted a planet of at least 50 Earth masses in the proposed orbit and that none of our current surveys would have had a chance to find one below 20 earth masses in most of its orbit.  They put the planets temperature at 47K due to residual heat from formation; which would make is 1000x brighter in infrared than it is in visible light reflected from the sun.
It should however be within reach of the LSST once it is completed (first light 2019, normal operations beginning 2022); so the question should be resolved within a few more years even if its far enough from Batygin and Brown's proposed orbit that their search with the Subaru telescope comes out empty.
My original attempt to handwave an estimate of detectability is below.
The paper gives potential orbital parameters of $400-1500~\textrm{AU}$ for the semi major axis, and $200-300~\textrm{AU}$ for perihelion. Since the paper doesn't give a most-likely case for orbital parameters, I'm going to go with the extreme case that makes it most difficult to find. Taking the most eccentric possible values from that gives an orbit with a $1500~\textrm{AU}$ semi-major axis and a $200~\textrm{AU}$ perihelion has a $2800~\textrm{AU}$ aphelion.
To calculate the brightness of an object shining with reflected light, the proper scaling factor is not a $1/r^2$ falloff as could be naively assumed.  That is correct for an object radiating its own light; but not for one shining by reflected light; for that case the same $1/r^4$ scaling as in a radar return is appropriate. That this is the correct scaling factor to use can be sanity checked based on the fact that despite being similar in size, Neptune is $\sim 6x$ dimmer than Uranus despite being only $50\%$ farther away: $1/r^4$ scaling gives a $5x$ dimmer factor vs $2.25$ for $1/r^2$.
Using that gives a dimming of 2400x at $210~\textrm{AU}\;.$ That puts us down $8.5$ magnitudes down from Neptune at perihelion or $16.5$ magnitude.  $500~\textrm{AU}$ gets us to $20$th magnitude, while a $2800~\textrm{AU}$ aphelion dims reflected light down by nearly $20$ magnitudes to $28$ magnitude. That's equivalent to the faintest stars visible from an 8 meter telescope; making its non-discovery much less surprising.
This is something of a fuzzy boundary in both directions. Residual energy from formation/radioactive material in its core will be giving it some innate luminosity; at extreme distances this might be brighter than reflected light. I don't know how to estimate this. It's also possible that the extreme cold of the Oort Cloud may have frozen its atmosphere out. If that happened, its diameter would be much smaller and the reduction in reflecting surface could dim it another order of magnitude or two.
Not knowing what sort of adjustment to make here, I'm going to assume the two factors cancel out completely and leave the original assumptions that it reflects as much light as Neptune and reflective light is the dominant source of illumination for the remainder of my calculations.
For reference, data from NASA's WISE experiment has ruled out a Saturn-sized body within $10,000~\textrm{AU}$ of the sun.
It's also likely too faint to have been detected via proper motion; although if we can pin its orbit down tightly Hubble could confirm its motion.
Orbital eccentricity can be calculated as:
$$e = \frac{r_\textrm{max} - r_\textrm{min}}{2a}$$
Plugging in the numbers gives:
$$e = \frac{2800~\textrm{AU} - 200~\textrm{AU}}{2\cdot 1500~\textrm{AU}} = 0.867$$
Plugging $200~\textrm{AU}$ and $e = 0.867$ into a cometary orbit calculator gives a $58,000$ year orbit.
While that gives an average proper motion of $ 22~\textrm{arc-seconds/year}\;,$ because the orbit is highly eccentric its actual proper motion varies greatly, but it spends a majority of its time far from the sun where its values are at a minimum.
Kepler's laws tell us that the velocity at aphelion is given by:
$$v_a^2 = \frac{ 8.871 \times 10^8 }{ a }  \frac{ 1 - e }{ 1 + e }$$
where $v_a$ is the aphelion velocity in $\mathrm{m/s}\;,$ $a$ is the semi-major axis in $\mathrm{AU},$ and $e$ is orbital eccentricity.
$$v_a = \sqrt{\frac{ 8.871 \times 10^8 }{ 1500 } \cdot \frac{ 1 - 0.867 }{ 1 + 0.867 }} = 205~\mathrm{m/s}\;.$$
To calculate the proper motion we first need to convert the velocity into units of $\textrm{AU/year}:$
$$205 \mathrm{\frac{m}{s}}\; \cdot  \mathrm{\frac{3600 s}{1 h}} \cdot \mathrm{\frac{24 h}{1 d}} \cdot \mathrm{\frac{365 d}{1 y}} \cdot \mathrm{\frac{1\; AU}{1.5 \times 10^{11}m}} = 0.043~\mathrm{\frac{AU}{year}}$$
To get proper motion from this, create a triangle with a hypotenuse of $2800~\textrm{AU}$ and a short side of $0.043~\textrm{AU}$ and then use trigonometry to get the narrow angle.
$$\sin \theta = \frac{0.044}{2800}\\ \implies \theta = {8.799×10^{-4}}^\circ   = 3.17~\textrm{arc seconds}\;.$$
This is well within Hubble's angular resolution of $0.05~\textrm{arc seconds};$ so if we knew exactly where to look we could confirm its orbit even if its near its maximum distance from the sun. However its extreme faintness in most of its orbit means that its unlikely to have been found in any survey. If we're lucky and it's within $\sim 500~\textrm{AU},$ it would be bright enough to be seen by the ESA's GAIA spacecraft in which case we'll located it within the next few years. Unfortunately, it's more likely that all the GAIA data will do is to constrain its minimum distance slightly.
Its parallax movement would be much larger; however the challenge of actually seeing it in the first place would remain.
Comment: Note here http://astronomy.stackexchange.com/questions/13280/how-would-parallax-affect-an-object-at-200-1000-au-ie-the-9th-planet/13283#13283 almost everyone (including me) forgot about the parallax, which is much bigger than the proper motion. It would be clearly identifiable by a large telescope within days. Gaia is all-sky, but limited to about 20th Mag.
Comment: The proper motion is massive and easily detectable, but you would need JWST (or perhaps just HST) in order to measure it and they have small fields of view, so you'd need to know more-or-less where it was.
Comment: Actually this is just at the faint end, and of course mabe its brighter in the IR. I read that the Subaru telescope is already looking.
Comment: For anyone who read earlier versions, I made an ~60x error in calculating proper motion at aphelion; it would be readily observable in Hubble observations; but is probably too faint to have been picked out in any proper motion surveys.
Comment: Such a great answer. At aphelion, how bright would the sun appear from Planet Nine? http://astronomy.stackexchange.com/questions/13282/how-bright-would-the-sun-appear-from-the-hypothetical-planet-nine-proposed-by-ca
Comment: @RobJeffries: I'm glad I remembered it:-) Still, it might be difficult to see, depending on the orientation, so it might be best to do the search at 3 month increments. Hmmm...
Comment: @RobJeffries yeah, I facepalmed when I realized I'd forgotten that too.  I saw that question last night; but was too brainfried to attempt another answer at that point.
Answer: The position of the hypothetical object is not known with any certainty, so it's hard to know where to point your telescope.
The paper proposes a wide range of orbital distances anywhere from 400 to 1500 AU semi-major axis, with a perihelion (closest approach to the sun) of 200-300AU. This is 8 times as far as Neptune. (I didn't read the article closely enough to determine whether the body would be near perihelion or not at present; it could be over 1000 AU away, 30 times Neptune's distance.)
With a mass of 10 Earths, we would expect the body to be something like 2-5 times Earth's radius -- somewhat smaller than Neptune.
The combination of distance and size suggests the body would be far fainter than Neptune, no brighter than magnitude 16.5 at perihelion, and likely much dimmer.
Comment: See my updated answer below.  The problem you and I made was using a 1/r^2 falloff with distance; when since we are talking about reflected light 1/r^4 is the correct term.  As a result, even at its closest it would be far fainter than your estimate.
Comment: If the orbital period is $\sim 30,000$ years, then the proper motion on the sky will be a massive $\sim 40$ arcsecs/yr. If it were as bright at $V=16$ I'm surprised this hasn't been picked up already in photographic surveys. It might be tricky because the proper motion is too big! Either way, a candidate could be confirmed in a matter of weeks if identified.
Comment: I'm not much of an astronomer (I answered this Q when it was in space.sx rather than astronomy.sx). If you want to take a stab at reformulating the last paragraph, please do! I'm also not totally sure of the magnitude computation.
Comment: @DanNeely I had just figured that out myself. This is a serious error in the answer.
Comment: Ah! Of course. Good catch.
Answer: Citing the original article:

We find that the observed orbital alignment can be maintained by a distant eccentric planet with mass $\geq \approx 10$ m⊕ whose orbit lies in approximately the same plane as those of the distant KBOs, but whose perihelion is 180° away from the perihelia of the minor bodies.

and

As already alluded to above, the precise range of perturber parameters required to satisfactorily reproduce the data is at present difficult to diagnose. Indeed, additional work is required to understand the tradeoffs between the assumed orbital elements and mass, as well as to identify regions of parameter space that are incompatible with the existing data.

So, finding out likely orbital parameters is work in progress.
Answer: Batygin and Brown made a website which describes the search for the 9th planet in clear terms. They specifically note the following:

perihelion (its closest approach to the sun) at around a Right Ascension in the sky of 16 hours, which means that the perihelion position is straight overhead in late May. Conversely, the orbit comes to aphelion (the furthest point from the sun) at about 4 hours, or straight overhead in late November.

So to look for it, one should look along the ecliptic, concentrating mostly on the area directly overhead in late November. Note that this is the part of the sky where the galactic center also appears. The inclination is estimated to be 30 degrees, plus or minus 20, so that distance from the ecliptic should be searched as well.
Answer: If you had access to a sufficient telescope, you could theoretically see it, if you looked in the right place (although no one knows where the right place might be). But if it's anywhere near aphelion there are only a handful of sufficient telescopes in the world (let's say an 8m mirror or larger), so I think it highly unlikely that you have access to one of them.
Comment: While this is technically an answer to the question, it is sparse on the things that make good answers (citations, detailed explanations, and math).

9th planet location?


Applying for UK Visitor visa for daughter's graduation

Question: My husband and I are applying for a UK standard visitor visa ( tourist) to attend our daughter's graduation ceremony and travel a bit in UK and Europe. We filled in the form that we will be staying independently and paying for the trip ourselves, and gave our daughter's contact detail and said yes to the question of will we be visiting her. The contact address we have given is the hotel we have booked. On confirming the application, the visa confirmation question however has a prefilled no to the question is the purpose of your trip to visit/stay with a close relative who is settled in the UK? Is this because she is a student and temoporary resident or have we done something wrong in the application?
Answer: You did not do anything wrong, but you do need to read the guidance.
If an applicant is visiting a close relative who has UK permanent residence (also called ILR, also called "Indefinite Leave to Remain"), they need to fill out an additional form.  Visiting a close relative with ILR increases the risk factor so they need to examine more things.  This is explained in the guidance.

Booking a hotel and using it as your contact address tells them that you did not read the guidance, and they will examine your evidence more carefully as a result.  It is not a show stopper and no reason to panic if everything else is in order.  Next time, your UK contact address is your daughter's address and don't book hotels or air tickets until after the entry clearance has been issued. This is also in the guidance.

NOTE:  Red emphasis added to screen caps
Adding...
The box on your confirmation was preset to 'NO' because of answers you gave in Part 8 of the application.  You have no close family with permanent residence.
Comment: Thanks, but my daughter is only a temporary resident and a student, and does not have the money to host us. We are therefore only visiting her for the graduation, and have mentioned that and given her contact details as well. That is why my confusion
Comment: I have given them the address of the blocked, not booked hotel in answer to the question where will you be spending the major portion of your stay in the UK. I have given them my daughters contact details in answer to " is a close relative staying in the UK. I have said she is a student and a temporary resident. I have also mentioned that I will be visiting her. Which is why Im asking - Why is the visa confirmation question prefilled to "no" as the answer to will you be visiting a close relative.
Comment: @Radhika because the question is "is the purpose of your trip to visit/stay with a close relative who is settled in the UK" and your daughter is a temporary resident.


JLPT N4 - Actual required Vocabulary, Kanji and Grammar

Question: There are tons of study materials in book stores, in the Web and available as Apps, that claim to cater for the JLPT N4 test, but is there any reliable source for what is really required for N4 (or N3-N1 for that matter) ?
Study for N5 was easy, as it starts from zero, but all next levels seems to be floating somehow and many require quite different vocabulary and Kanji than others for the same levels.
According to your experiences, what are the closest sources to actual N4 requirements for meaningfull and efficient study purposes ?
Answer: For me, it worked to complete みんなの日本語初級 II (Commonly referred to as "Minna no nihongo 2") in terms of grammar and vocabulary. I just learned all of the vocabulary words and the grammar points for each chapter, completed the exercises and I did well in the N4 exam.
As for the Kanji, I can't answer your question because my approach is to learn the kanji for any new word I learn, which is overkilling as regards N4 kanji requirements.
Answer: I was searching for lists of words too at some point, and I fell on the JLPT FAQ:

Why is "Test Content Specifications" no longer available after the
2010 revision of the JLPT?
We believe that the ultimate goal of studying Japanese is to use the language to communicate rather than simply memorizing vocabulary, kanji and grammar items. Based on this idea, the JLPT measures "language knowledge such as characters, vocabulary and grammar" as well as "competence to perform communicative tasks by using the language knowledge." Therefore, we decided that publishing "Test Content Specifications" containing a list of vocabulary, kanji and grammar items was not necessarily appropriate. As information to replace "Summary of Linguistic Competence Required for Each Level" and "Composition of test items" are available. Please also refer to "Sample Questions."

So even the specification doesn't give an exact list of the content. They want you to focus your study on actually learning Japanese. Your best bet is to follow any courses designed for JLPT, they mostly all follow a similar format. Learn all the words you encounter, keep learning new words daily. If you're really worried, you could probably search for the pre-2010 specification, but that would defeat the purpose of why they changed it.


English equivalent for the Indian saying

Question: Is there an English equivalent for the Indian saying " A wandering monk and running water never get polluted".
Comment: What is the saying supposed to mean?
Comment: wandering monk is an ascetic who is not a member of any established order,he travels from one place to another,mainly subsisting on alms (an old ascetic tradition in India). As the ascetic never stays for a longer  duration at a  particular place,he never gets attracted or attached to men and materials at that place. Similarly when water is kept stagnant at a place it turns stale with passage of time and running water always wash away dirt and filth and in the process cleanses itself.This is the idea behind the saying.
Answer:
A rolling stone gathers no moss.
Comment: Please add an explanation as to how this corresponds to the Indian saying.
Comment: @MattE.Эллен I don't know what there is to explain. Please show what you have in mind by editing this answer or submitting a new one with an explanation (and then tell me to delete this one).
Answer: Here is the opening paragraph from Wikipedia's page on "A rolling stone gathers no moss":

A rolling stone gathers no moss is an old proverb, credited to Publilius Syrus, who in his Sententiae states, People who are always moving, with no roots in one place, avoid responsibilities and cares. As such, the proverb is often interpreted as referring to figurative nomads who avoid taking on responsibilities or cultivating or advancing their own knowledge, experience, or culture. Another interpretation equates "moss" to "stagnation"; as such the proverb can also refer to those who keep moving as never lacking for fresh ideas or creativity.
Comment: Welcome to ELU. This is potentially a very good answer, that could be improved with the addition of sources, references or further cited examples. For future reference, this kind of supporting evidence is usually a requirement for authoritative answers here.
Comment: Hello, Kiruthiga Kuppuswamy. I added a link to the Wikipedia page that you took the quoted paragraph from, and I formatted the quotation as a block quote. Your original presentation did not make clear to a casual reader that none of the wording in the paragraph was your own work. Please consider adding an explanation of how the Wikipedia paragraph bears on the question of why "a rolling stone gathers no moss" is equivalent to the Indian saying "a wandering monk and running water never get polluted." As yet, neither answer to the poster's question directly addresses that important matter.


Mobilization of units allowed on a territory with an industrial complex controlled by a power on same side?

Question: My friends an I were playing a&a 1941 and soviet union wanted to mobilize units in India. Is that ever allowed? If yes, when? I read through the whole book and I did not find anything about when you can do that.
Answer: You may only mobilize units in a territory you (not your ally) have owned since the start of the turn.  Additionally, you liberate allied territories when you capture them, immediately returning ownership to the original owner*. Thus the USSR cannot mobilize in India, since it is owned by the UK, not the USSR.
* - Details, it is technically possible to create a situation where the USSR could mobilize in India. It would require that the Axis captures both the UK capital, and India, then the USSR recapture India (a territory is not liberated if the owner's capital is in enemy hands), then on the following turn (after a full turn of ownership) the USSR may mobilize in India.
Answer: You can only mobilize in an area which 1) you control and 2) on which there is an industrial complex.
In the beginning of the game, India does not have an industrial complex. Nor does Russia control it. The "best" Russia can do is to advise her UK ally to 1) build an  industrial complex in India, then 2) build three pieces and 3) move them into Novosibirsk, or some other place of Russia's choice. Each of those activities takes up a whole turn.
As long as the UK (an ally) holds India, Russia cannot capture or control it. But suppose Japan 1) captures it and 2) builds an industrial complex and 3) allows Russia to "recapture" it. Then what happens?
Normally, Russia will have to return India to the UK, an ally. The exception to the rule is if the UK's capital is under occupation, say by Germany. Then since it is basically out of the game, Russia can keep India, build an industrial complex there, and mobilize the following turn.


Merging touching lines in QGIS

Question: I have a vector layer, in which structures (pipes under roads) are made up of multiple lines. I wish to spatially join all the lines that make up a single structure, but cannot figure out a way to do this. I've been messing around with things like "dissolve", but that merges all lines in the layer into a single feature. In the example below, I would like to join all of the orange lines that touch, resulting in 3 features.
Comment: In QGIS https://gis.stackexchange.com/questions/73519/merging-dissolving-polygons-by-common-attribute-field-in-qgis might help but you will need to cluster the lines and apply a unique ID to each cluster - dissolve and explode https://gis.stackexchange.com/questions/70710/exploding-multipart-polygons-within-shapefile-in-qgis then spatial join https://www.qgistutorials.com/en/docs/performing_spatial_joins.html the undissolved lines to the exploded lines and then dissolve by joined FID - this assumes you also need to retain another value like size, install date etc..
Answer: Have you tried simply dissolving your data into your single feature dataset, then perfoming a multi-part to single part? Such that each geometry would then be its own new record?
At a much grander scale, I think the approach you should take is to solve the problem on the creation of the dataset - rather than fixing this already erroneous dataset. There are too many variables (eg: Does the endpoint of line 1 snap to a segment on line 2? - If it doesn't your data is crap and you will end up with lines going everywhere).
Im not sure if you have access to the raw data or the process that was used to create the lines, so this might not even be possible at all.
But assuming you have the raw pipework dataset, you could a few new approaches.
Approach 1 - Store the 'under road' attribute as master data against the original pipe data.
It is not uncommon to store attributes about a linear infrastructures 'situation' (eg: Above ground/below ground - or perhaps whether its inside of conduit etc)
This would require generating polygons of the road reserves, splitting the pipe records where they intersect with those road reserves. Then assigning the attribute to the records that are within the road reserve polygon. (Ideally, then create a capture business rule for the pipework data, such that it tests for this condition).
Approach 2 - Dynamically recalculate the pipe sections that are beneath a road. This would use almost the same technical logic as approach 1, but instead of storing it as an attribute, a new layer/view is created dynamically, possibly by a geoprocessing engine of some description. 'Show the pipe sections (or portions of pipe sections) that overlap road reserve polygons.
Both the above solutions assumes:

you have access to the original raw pipe data.
access to the road reserve polygons.
Comment: Was able to use your approach(the first lines) to merge the touching lines. Simple and straightforward.

Merging touching lines in QGIS


Can I submit the results of a poster to another conference as a full paper?

Question: If I presented a poster at a conference that contained the results of some research, can I then write a paper using those same results and submit it to another conference as a full paper?
Comment: What's the field?  This will depend on your field's norms, and to what extent conference presentations are considered "publications".  For instance, @semi-extrinsic's comments aren't true in my field (math), where you can present a project in dozens of conferences or posters and nobody expects this to be mentioned at all in the final published paper.
Comment: Most importantly: Was the poster associated with a publication other than an abstract?
Comment: For any serious conference you are required to refer to previous work in your full paper. If you mention that the exact same result was presented at a previous conference, I'm guessing your paper would be rejected. Not mentioning that it's been presented at another conference is unethical. The only good option is doing some more work, such that the full paper is an extension of the work presented in the poster. (An obvious exemption is if you're invited to resubmit a paper, e.g. to a higher-level conference.)
Comment: @NateEldredge when you say my comments don't apply to your field, I take it you mean the "I'm guessing the paper would be rejected" part? Or would you also avoid mentioning in the final paper that this was presented previously one or more venues? I'm just curious. For reference, in my field (comp.phys) it's quite common for all conference contributions, even the posters, to have an accompanying paper in the proceedings.
Comment: @semi-extrinsic: No part of your comment really applies in my field (except the first part about citing previous work; but previous conference presentations by the same author on the same work do not count).  I have never seen a published paper mention the conferences at which the work has been presented.  Note that conferences in my field almost never have published proceedings.  If you did publish your work in conference proceedings, then what you said applies.
Answer: This depends on the customs of the field and the venue. I will answer based upon my experience from an HCI-related subfield of CS:
Conferences usually have some requirement of novelty for published works. Therefore, if a paper associated with the poster already appeared in some proceedings of the first conference, you might not fulfil this requirement. First, however, some different cases might apply:

If the poster was not "formally published" (i.e. did not appear as a (short) paper in any kind of proceedings), you should be good to go.
If the poster was supposed to be "formally published", but the conference organizers never got around to setting up the proceedings of the poster session, you're in a bit of an inconvenient situation. Your work is not published in a way that it can be cited (well, it can, but it doesn't look as verifiable as other papers and is not archived by any publisher), but it has been presented. You may want to contact the conference organizers in this case whether publishing your work again is ok, or else you may want to wrap your work in something larger (i.e. present something new, but reiterate the points from the poster as a part of the exposition).

Even if your poster was published in some kind of proceedings, there may be some options:

Posters are often allowed to present work in progress. If your poster (and the connected paper) was presented in a way to present work in progress, your new conference paper might indeed present the final state of whatever you devised. This can essentially match the content of your poster, but provide more details (see also below).
Even if the poster presented final results, the term "results" seems to be seen in a very wide sense at least in my fields, possibly in others. A full conference paper provides much more space than a poster paper, and on the poster, you probably presented different (more visual) things than you would in text. As such, you can shift the focus of your conference paper compared to the poster; where the poster focused on the results, the conference paper might discuss the methods used to obtain the results in depth, including design decisions, citations of similar experiments, a verification of the reliability of your experiments, etc. This kind of description can be useful for the community and subsequent works, and as such should provide enough new content, despite being based upon the same material as the poster.
Comment: Thank you O. R. Mapper for your help ,  My Poster result was never published so im good to go , by the way, im in computer science fielde
Answer: This depends a great deal on the field and conference that you have in mind. Generally, it should be stated in the call for papers. If there is no explicit mention of novelty requirements, that probably means the research cannot be resubmitted in a longer form or that the field has a very clear, established convention.
To take an example from a premier conference in Computer Science, a poster paper can be resubmitted, with the addition of novel contributions, provided that the previous submission was sufficiently short and not published in a journal:

Every research paper submitted to SIGMOD 2016 must present substantial novel research not described in any prior publication. In this context, a prior publication is (a) a paper of five pages or more presented, or accepted for presentation, at a refereed conference or workshop with proceedings; or (b) an article published, or accepted for publication, in a refereed journal. If a SIGMOD 2016 submission has overlap with a prior publication, the submission must cite the prior publication, along with all other relevant published work, following the guidelines in the Anonymity Requirements for Double-Blind Reviewing section below.

However, the paper is still likely to be rejected if there is not sufficiently more material in the new paper; I cannot imagine any venue of high quality simply republishing material that has already appeared somewhere else.


Does Dropbox offer any protection against infected files?

Question: Does Dropbox offer any protection against sharing files which are infected?
To give more info, my friends and I are currently working on a college project. We find it much more convenient using Dropbox to discuss and keep in touch. Is it possible to get infected if one of my colleagues accidentally shared an infected Word Document file on dropbox?
Comment: This is a question for Dropbox support.
Comment: You can try sharing the EICAR antivirus test file. http://www.eicar.org/85-0-Download.html
Answer: Yes, it is possible. Just as you could get infected if one of your colleagues shared and infected Word Document file by email or a usb flash drive.
(I am assuming that you are also triggering the payload by opening the infected document, executing the program, etc. A virus file residing in your hard drive won't infect you by its mere existence.)
Dropbox doesn't scan your files with an antivirus, as stated in https://www.dropbox.com/help/8406. But even if it did, it would still be possible to get infected by a virus not detected by its solution.
You should take the normal protection measures, such as running an up-to-date antivirus in your computer. But there's no reason to stop using Dropbox just for fear of virus. The risk -if they happen to get infected- is in sharing the files with your colleagues. And I assume that's something you want (need) to do ;)
PS: The only difference would be that using Dropbox may make you receive the infected file faster. But on the other hand Dropbox history feature would also allow you to recover a pre-infection version of the files, which might not be available otherwise.
Answer: You can upload infected files to Dropbox. They scan their servers for malware on a somewhat frequent basis.
I've heard that they event block copyrighted content from being shared/downloaded. So, every file inspected when it's uploaded.
But to directly answer you question, yes, you can infect your computer if one of your colleagues uploads an infected Word document.
Comment: I've been part of a dropbox group that uploads/shares lesser known music for the group of friends to find new music to listen to. While the point of the group is to find new music then buy it on your own, the music still shows up on my local PC where I can move it to a static folder. Unless the copyright activity is very new, I can confidently say this statement is false. Not that it helps the original question, but throwing it out there in case people wondered about it from your answer.
Comment: Dropbox will keep a checksum of each file, on the extremely rare occasion that a file is reported as infringing copyright then it will get cleaned out of everyone's account .
Comment: If the hash matches, the people you share the file with will see a notice saying the file can't be downloaded due to copyright issues and will not appear on the file list. If you're using free basic accounts and abusing bandwidth maybe they will cancel your account. For paid users, the file stays in your account but can't be shared.


CAPM goodness of fit

Question: I want to test the CAPM. I have collected monthly data from 1-9-2012 to 1-9-2017. I have data from the return of Standard&Poor's 500 and data from various US companies. The beta's seem right, but my goodness of fit ($R^2$) are low: Ameren 0.0614, Apple 0.2456. My question is: Can this be right? If you're testing the CAPM or am I doing something wrong. I used the CAPM regression $R_{i,t}-R_{f,t}=\alpha_i+\beta_i(R_{M,t}-R_{f,t})+e_i$.
Comment: What estimation procedure are you using? Are you running regressions in two stages: one to find the betas and the other to test the CAPM? If this is the case, which regression are you talking about when you talk about the $R^2$ ?
Comment: I am using OLS. I just one regression: the regression descriped above for 20 stocks. Fama-Macbeth had in their 1973 paper beautifull R^2's, so I was wondering if I did something wrong. But my question was answered splendidly by a number of people below. My thanks!
Comment: OK. Sounds good. But just to clarify, the Fama-Macbeth procedure uses two regressions. The first is a time series regression to obtain the betas. The second is a cross-sectional regression to regress the risk-premia of each security *on their betas*. The CAPM hypothesis puts restrictions on the second regression, not the first. So, since your question is about interpreting the first regression, your question doesn't really have anything to do with testing the CAPM. This confusion is why I claimed that the question was probably a little ambiguous.
Answer: $\beta$ is the measure of the sensitivity of stock returns to market returns. This has nothing to do with the value of $R^2$.
Your results appear to be fine, you can get significant beta estimates but low $R^2$. Why?
As measured by $R^2$, 24.56% of variation in Apple returns is accounted for by the variation in the market index, $S$&$P 500$. Clearly, there must be other factors that determine the remaining 75.44$% of variation in the Apple returns. Other factors that you could include in the model are copmany size and market to book value (Fama and French Three-Factor Model). By including these omitted variables in your new model, you may achieve higher r-squared value.
Answer: First note the variables $\alpha_i$  and $e_i$ are completely degenerated, there's no way to tell one apart from the other, unless you have a strong prior on them. The model should look something like
$$
R_i = R_f + \beta (R_{m,i} - R_f) + e_i \tag{1}
$$
which can be rewritten in the form
$$
R_i = \beta_0 + \beta R_{m,i} + e_i \tag{2}
$$
For the example below I selected Apple as my asset (with returns labeled rasset) and S&P 500 as the market index (with returns labeled rmarket), this for the window 2012-09-01 to 2017-09-01.
This is a summary of OLR applied to Eq (2)

You're right, the correlation between the two is low, which you can actually already see from a plot of the returns

However, you can see from the table above that
$$
P(>|t|) = 0
$$
for the coefficient $\beta$, which means you're almost 100\% sure that $\beta\not = 0$
Comment: This question doesn't (at least directly) address the OP's concern over the $R^2$.
Answer: Note: I'm adding this simply to supplement the other answers.
Also, I'm going to assume that you're talking about the $R^2$ of the time series regression
of security $i$ on the market portfolio $M$
$$
R_{it} = \alpha_i + \beta_i R_{Mt} + \epsilon_{it}.
$$
As @london described in his answer, the $\beta_i$ is simply the sensitivity of security $i$
to the market. In the Sharpe-Lintner CAPM, as well as in other variations, systematic risk is then defined as $\beta^2 \cdot \sigma^2_{R_M}$ and idiosyncratic risk is $\sigma^2_{\epsilon_i}$.
Thus, the $R^2$ (r-squared) of this regression should not be interpreted so much as
"goodness of fit." Rather, it is simply a measure of the ratio
of ratio of systematic risk to total risk (systematic plus idiosyncratic risk). As @london described, total risk includes all the other things that drive
security $i$'s returns. To see this,
note that the definition of $R^2$ in the population sense
is
$$
R^2 = \frac{\beta_i^2 \sigma^2_{M}}{\beta_i^2 \sigma^2_M + \sigma_\epsilon^2}.
$$

CAPM goodness of fit


How many calories does it burn to regrow a liver?

Question: The liver is rather unique in being able to regrow after partial donation. More interestingly, growing organs in general uses loads of energy, and while I'm not exactly advocating for advertising liver donation as a weight loss strategy, how many calories exactly does it take to regrow a liver?
Comment: Funny how this is a hot question.
Answer: To get the answers started, though admittedly with a very rough estimation, I'll add my own idea of a lower bound of calories burned to regrow an entire liver.
Because basic laws of thermodynamics state that to produce 100 calories worth of food requires at the very least 100 calories worth of energy, an estimate on the nutritional content of the liver itself should be a reasonable lower bound for how many calories it takes to regrow a liver.
According to Nutritiondata.com, raw pig liver has 134 calories per hundred grams, and raw cow liver has 135. Given the relative consistency, right around 134 should be a reasonable estimate for the caloric content of human liver, not that any of us really want to test that one out. Now according to Hypertextbook referencing a number of sources, average mass of a human liver is around 1.5 kg.
Finally, UCSF Medical Center states that the majority of a liver is regrown in the first two weeks. In theory, this would mean that in the case of a whole liver donation, half the liver would be regrown in the first two weeks after donation. However, whole liver donations tend to not lead to regrowth, with this study (unfortunately paywalled) stating that around 25% of the liver needs to be left to initiate regrowth. For arguments' sake however, and considering we're already vastly underestimating the caloric needs for liver regeneration by assuming 100% efficiency, let's roll with it.
So 1.5 kg of liver at 134 calories per 100g yields 2,010 calories per liver, of which 1,005 would regrow in the first two weeks, or no less than 71.79 calories per day to regrow a liver for the first two weeks after loss/donation. Notably, Raymond Lindeman's 10% law implies that regrowing a liver may burn 10x this number of calories or more, so I'm really curious to see what answer someone who knows more than I do might provide.
Sources:

http://nutritiondata.self.com/facts/pork-products/2195/2
http://nutritiondata.self.com/facts/beef-products/3468/2
https://hypertextbook.com/facts/2004/MaryPennisi.shtml
http://ucsfhealth.org/education/evaluation_to_be_a_living_liver_donor
http://www.journal-of-hepatology.eu/article/S0168-8278(00)80412-2/pdf
http://www.biologyexams4u.com/2017/07/ecology-notes-raymond-lindemans-law-of.html