Is copying a photo idea legal?

Question: I saw a picture on google which I would like to take. I won't copy him 100%. I loved that idea
Comment: Legality is a matter of your local jurisdiction. So where you are from matters here.
Comment: It probably depends what "the idea" was. Girl on cityscape lit from one side in blue... who would know? Girl who looks like Marilyn, set in 4 frames in garish colours, the Warhol estate might come looking for you.
Comment: As far as I know, ideas are explicitly *not* protected by copyright, only their expression.
Comment: Why do you care? What are you going to do with the photo?
Comment: But just to copy someone´s idea is plagiarizing and IMHO morally not ok. If you just copy the idea give credit to the orginial "author" of the idea at least.
Answer: In general, copyright covers specific expression of an idea, not the idea itself. Also, while law does vary by jurisdiction, international treaties make this aspect, at least, fairly consistent.
However, note that in practice, this covers a lot more than you might think. Note that for example specific, distinctive characters can fall under copyright, so, for example, you can't say "Oh, I'm just using the idea of Harry Potter in a story." An analogy might apply in a visual-arts case. If the photo idea you are copying has distinct creative elements which your copy also expresses, copyright could... come into the picture. (Pun inevitable. Sorry.)
This isn't just theoretical: consider the case of the red bus on the Westminster bridge: here, a tea company used a selective-color photograph of a red bus on a black & white background, and they were successfully sued by a souvenir company which sold a similar photograph:

Read more about this on this law blog;
Many photographers (and lawyers!) feel a little uncomfortable with this precedent, but one key thing is that intention matters:

The judge noted that "the whole point of this case is that [the defendant wants] lawfully to produce an image which does bear some resemblance to the claimant's work."

It's also worth noting that this is a commercial case. Copying what others do is an important means of learning, and it's probable that for most uses a fair use defense would apply. If you're copying the work and then using it in a way that competes with the original, probably not. (But note in any case that there's no a priori fair use under most copyright law; it's a defense you can use if you are sued.)
Personally, I hope that the judge in this case was not particularly aware that selective color like this isn't particularly creative or interesting (and is even provided as an automatic feature in many cameras). Without that awareness, it's easier to see this as a distinctive and unique composition with special artistic merit. If "used that camera mode on a distinctive object" is all it takes for copyright to be asserted... that's a pretty strong.
Comment: Given the broadness of copyright and trademark legislation, it's getting ever more risky to take photographs of just about anything. Think the company that trademarked a tree (the physical tree) and sued anyone they could find making photos of it...
Answer: It is not inherently bad to copy an idea, though your actions could make it immoral.
When learning, especially studio lighting, it is commonplace to copy images to recreate scenes.
When shooting weddings, many brides will Pinterest a favorite photo or two and you won't get out alive without getting that shot.
All that being said, one should never try to pass off these ideas as their own. Always credit your inspiration.

Is copying a photo idea legal?


In regards to the Gibbs free energy equation, it seems that the two terms oppose one another, Enthalpy and -TS. Can you explain this?

Question: So for example, if H is endothermic, then the enthalpy term is positive, meaning energy is absorbed by system overall, meaning net bonds broken, meaning the equation leans towards nonspontaneity. If entropy is negative, then -T∆S is positive, meaning net bonds formed, meaning equation leans towards nonspontaneity. It appears that they oppose one another in regards to bond formation...
Comment: Endothermic does not necessarily mean that there is net bond breakage. For example, you can break one strong bond and form many weak ones, and the number of bonds will increase even though the reaction is endothermic.
Answer: It is not about opposing terms but from experimental necessity. In the early days before the second law was understood it was assumed that the most efficient utilisation of chemical energy consisted of converting all the heat into work. But experimentally this proved not to be the case.
Lewis and Randall (Thermodynamics) put it very clearly

It is true that according to the first law, the external work performed must be equal to the loss of heat content of a system, unless some heat is given to or taken from the surroundings, but this is precisely the point first seen by Gibbs. When an isothermal reaction runs reversibly $T\Delta S$ is the heat absorbed from the surroundings, and if this is positive, the work done will be even greater than the heat of reaction.

Thus entropy and so the free energy had to be invented to understand the experimental data.
Comment: discovered and explained not invented
Answer: The combined effect of $ \Delta H-T\Delta S $ is a measure of spontaneity. The individual terms (i.e., $ \Delta H$ and $T\Delta S $)  are not the actual measure of spontaneity. But in general we say that exothermic reactions are spontaneous (it is when $T \Delta S $ term is negligible in comparison with $ \Delta H$) and sometimes if $\Delta S>0$ we say that the process is spontaneous (if $\Delta H$ term is negligible in comparison with $T\Delta S$ term).
Comment: Itepends on the direction the system is displaced from equilibrium. the differences determine where the equilibrium lies
Answer: At equilibrium, $$\Delta G = 0 = \Delta H-T \Delta S$$ $$\Delta H = T\Delta S$$  This means that a system at equilibrium is stuck there unless matter [chemical potential] or energy is changed to perturb the equilibrium.
Ice + heat = water; add some heat; $T \Delta S$ increases; $\Delta H$ must now increase; this means that heat must be removed and ice melts to maintain equilibrium. Spontaneity direction depends on which side the reaction is displaced from equilibrium. Both directions are spontaneous. One way is energy driven, the other way is entropy driven.
Energy and entropy really do work as a team.
Comment: Please visit [this page](http://chemistry.stackexchange.com/help/notation), [this page](http://meta.chemistry.stackexchange.com/q/443/) and [this one](http://meta.chemistry.stackexchange.com/q/86/) on how to format your future posts better with MathJax and Markdown.


efficiency of my node for my website?

Question: How can I calculate the efficiency of my node in the last 10 or 20 cycles? Are there any special RPC codes for this for add rewiew in to my website?
Answer: There are no special RPC APIs for this. You must query either A) tzscan (or other chain indexer) for each cycle's number of successful bakes/endorsements for your tz1 or B) scan the blockchain yourself for the same information. Once you have $numberOfGrantedEndorsements and $numberofMissedEndorsements, then you can calculate the efficiency.

efficiency of my node for my website?


VirtualBox kernel modules do not match this version of VirtualBox

Question: While using VirtualBox, I am getting the error shown in the picture. I executed the command suggested, but still I am getting the error.
Comment: Welcome to AskUbuntu.  If you write out the error message it will be easier for you to find a resolution.  The system will even give suggestions where the same errors has been resolved by others.  You loose this potential by using pictures rather than text.  Also the images takes up a lot of unnecessary space on the server.  Try to user images when text won't suffice.  In this case the specific text error is clear.
Comment: These instructions work for Ubuntu 17.10: sudo apt-get autoremove sudo /sbin/vboxconfig from [this post on VirtualBox Forums](https://forums.virtualbox.org/viewtopic.php?f=7&t=86240)
Comment: Most dialogue windows in Linux let you select, copy and paste their text content by the way.
Answer: The image in the picture is giving you this error message: rtr3initex failed with rc=-1912 (rc=-1912) Ubuntu
It's telling you you have a mismatched install.  Your kernel modules do not match your installed version.  The kernel modules are packaged in virtualbox-dkms in the repository.
You have most likely installed it from the repository.  But failed to install all the modules, or you installed it, performed and upgrade and the modules didn't get completely upgraded during one of your system's updates.  You can fix this by uninstalling it and reinstalling it, which will install the necessary modules.  You do this with:
$ sudo apt remove --purge virtualbox
$ sudo apt install virtualbox
$ sudo apt install virtualbox-dkms

Completely removing virtualbox and it's dependencies will not affect your VM's.  Just the applicaton itself.
Alternatively you can download the latest version of Virtualbox from http://Virtualbox.org.  The download page for linux is: https://www.virtualbox.org/wiki/Linux_Downloads.
You can append this to your /etc/apt/sources.list file to add the official developers repository:
deb http://download.virtualbox.org/virtualbox/debian xenial contrib

You can download and add the security key with:
wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -

Then grade what you currently have with:
$ sudo apt update
$ sudo apt upgrade

If you purged the previous version then reinstall it with this after the upgrade command above:
$ sudo apt install virtualbox

If you download and install from virtualbox.org the kernel modules for the developers version will automatically be compiled and installed.
Comment: @Royi I take it that you are saying the error is the exact message.  Run these commands: **(1)** `sudo apt remove --purge virtualbox-dkms` ; **(2)** `virtualbox-dkms` .  You may have to run this afterward: `/sbin/rcvboxdrv setup`
Comment: Hello. I had VirtualBox 5.0.4 which freezes my system (I have Kernel 4.13.xx). Then I purged as you wrote above and installed using Virtual Box site. Yet I still get this message. What should I do?
Comment: I ran #1, but now #2 says doria@doria:/home/doria$ virtualbox-dkms
virtualbox-dkms: command not found
Comment: @L.D.James You don't need to run `virtualbox-dkms` (you removed it, no?). Anyway it works.
Answer: Run:
sudo apt-get autoremove
sudo /sbin/vboxconfig

Comment: Welcome to [ubuntu.se]! Could you [edit] your answer to explain how this should help?
Comment: This helped actually in my case. Thank you :)
Comment: Worked for me! Ubuntu 18.04 host running Windows10 Guest.
Answer: I see this is an old question, but I just had this problem and, while the answers already listed here may well be correct and solve the problem, they aren't actually necessary and theres a much easier way to fix it.
If Virtualbox has previously been installed and was working, then this problem can arise after a system update, as it did with me. It seems that VB is updated, but the dkms is not.
In order to obtain the correct dkms, it's necessary to also perform an 'upgrade'.
You can check if this is the case by running:
apt list --upgradable

and the dkms package will likely be shown as an available upgrade.
If so, simply run:
sudo apt upgrade

and the problem will be fixed.
Comment: Life saver... thx!
Answer: From L. D. James's comment:
sudo apt purge virtualbox-dkms
sudo /sbin/rcvboxdrv setup

I've done this after a virtualbox downgrade and it worked.


CV errors in graduate application

Question: What errors do applicants make in their CV while applying to US graduate programs, apart from obvious errors like spelling, grammar, formatting etc.?
Comment: Welcome to Academia.SE! On this forum we discourage "list" questions such as this one. Check out [help/on-topic] site to see what we tend to look for... we want questions to be more directly answerable, rather than just lists of information.
Answer: Here are some that I encounter

Listing all of your achievements, rather than your notable ones. No one cares that you got 3rd place in a high-school biology competition. List things that are truly outstanding, not minor stuff.
Not selecting referees carefully - make sure that the reference letter writers you pick actually like you and would write positive letters. In particular, many universities would largely disregard reference letters from lecturers you took a class with. Unless there was some special relationship (a joint project, a really outstanding performance in class), the letter amounts to 'this student attended my class, and got a good grade'; this is information that I can get reading your transcript.
Writing unqualified achievements. I'm not talking about outright lying (obviously don't), but more things like "talented writer". Ok, you're a talented writer - how about some evidence to back it up? Did you win any competitions? Did your work get published anywhere?
CV sections not ordered according to importance: when someone reads your CV, they're probably reading at least 50 more that day. I don't need to wade through unimportant information (languages you speak comes to mind) before I get to what I want to know. Think - what would make a person pick me out of the bunch? Write that first.
Comment: *In particular, many universities would largely disregard reference letters from lecturers you took a class with.* --- This part seems extremely strange to me (the rest of what you said seems fine), but maybe by "lecturer" you specifically mean a very low-level teacher (e.g. graduate T.A., post-doc, visiting faculty, etc.) rather than a tenure-track or tenured faculty member. Maybe this is also somewhat field-dependent, since in mathematics (especially pure mathematics) a candidate's teachers are pretty much the only people who could write such letters.
Comment: *(BTW, I originally upvoted your answer.)* --- Looking at this the next day, it seems to suggest that I upvoted your answer and then canceled my upvote at a later time. What I meant is that when I originally read your answer, I upvoted it because, as I said in my first comment, "the rest of what you said seems fine" (and I have not canceled my upvote).
Comment: While I certainly can't attest to what happens in other disciplines (or in other departments!), this is certainly true from what I encountered, and from speaking to colleagues in my field. I can also say this from the pool of letters I had to read. Generally letters from lecturers who don't know the student tend to be generic and uninformative.
Comment: *letters from lecturers who don't know the student* --- I don't think anyone would disagree with this, but you did not originally have "who don't know the student". For what it's worth, I don't recall anyone during my undergraduate or graduate years using anyone except a course teacher for a reference, but this was before [REU summer research](http://www.ams.org/programs/students/emp-reu) and other opportunities (such as [this](https://en.wikipedia.org/wiki/Budapest_Semesters_in_Mathematics)) were generally available in math. (BTW, I originally upvoted your answer.)

CV errors in graduate application


Story where main character fights crayfish knights and leeches

Question: Trying to remember name and author of story where main character gets turned into a frog or something and is underwater.  And the crayfish are knights and it is like a society. Gets yanked back out of the stream to normality before the battles are over.
Answer: I think I figured it out, myself.  It is Land of Unreason by American writers Fletcher Pratt and L. Sprague de Camp.

Fred Barber, an American staying as a guest in an English country home during World War II, consumes a bowl of milk left as an offering for the fairies, substituting liquor in its place. The rightful recipient of the offering, drunk and offended at the substitution, takes vengeance by kidnapping Barber off to the Land of Faerie as a changeling, a fate normally reserved for infants. He finds Faerie beset by a menace echoing the war in his own world. Trapped in a magical realm where rationality as he knows it is turned upside-down and failure to follow the rules can have dire consequences, Barber undertakes a quest in the service of Oberon, the fairy king, in order to be returned to his own world. The outcome, befitting a realm in which nothing is as expected, is one that neither he nor the reader anticipates, for Fred Barber is not quite the man he thinks he is.

It indeed has crayfish knights, as per text in the Internet Archive copy, which can be borrowed.

The crawfish-knight was actually puffing in his indignation and Barber judged it prudent to change the subject. "You know," he said, "I'm on rather a serious mission as it happens. I'm looking for a piece of property that belongs to the Mother of the Gods, and I've been led to believe it might be in Whoozis' possession. Could you suggest how I might go about recovering it?"
Comment: Are you the same user who posted this question? If you are, we'd be grateful if you'd merge your new account with the previous one by following the instructions provided [here](https://scifi.stackexchange.com/help/merging-accounts). Once that process is complete, you'll then be able to mark your answer as [accepted](https://scifi.stackexchange.com/help/accepted-answer) by clicking on the check mark beneath the voting buttons. It's this site's way of formally indicating that a query has been solved to the querent's satisfaction.
Comment: I was on a different device, sorry.  I just like posting as disposable guest, don't merge please.  Feel like it keeps me in check to be a second class citizen.  Fuzzy had an awesome answer and deserves the points and all.  I'll see if I can accept it on my phone, so you get the green check.  P.s.  Thanks for the kindness to forum newbies.


Full list of ISO-639-6

Question: Is there a full list of codes in ISO-639-6:2009 (Codes for the representation of names of languages — Part 6: Alpha-4 code for comprehensive coverage of language variants) such as a cached mirror or repository? The original registry GeoLang no longer provides the query services as shown in this archived page. I know that it's currently deprecated but it's good to know the completeness of the system.
Answer: Most likely, there never was a complete list. In October 2014 Peter Constable wrote the following in an e-mail to the IETF-languages mailing list (emphasis mine):

While ISO 639-6 did get approved and published, the code table for 639-6 has never been made fully available in a usable manner. What data has been available has been looked at by lots of people with a response that they don't find it particularly useful for any practical application. Moreover, the agency that was designated as registration authority appears to have ceased its operations. In a nutshell, 639-6 had in many respects failed.

The agency referred to in this message is GeoLang (as mentioned in the question). Technical committee ISO/TC 37/SC 2 lists ISO 639-6:2009 as a "withdrawn standard".
Comment: Based on the clues from language wikis, it's very likely that there was a full list. What I don't understand is that it's a great project first time in human history to codify almost every language and dialect in the world. Standardization is important for usage in data science and computer programs. Yet it's deprecated with such absurd excuses. There is not even a backup. So many years of effort are completely discarded... I can't find anything more confusing and annoying than this...
Comment: @EurekaZheng In standardisation, terminology matters. The standard was not "deprecated"; it was "withdrawn". Note also that the standard itself did not provide a list but only criteria for such a list.
Comment: @EurekaZheng Important for data science and computer programs? Most of the time, ISO 639-1 is enough; Wikipedia has only 5 Wikipedias in the 50 largest that need an ISO 639-3 code. And we have 639-3. Few need more details of ancient languages or dialects of modern ones, and those that do know what they need more than any one-size-fits-all standard could. Not to mention that ISO 639-3 has enough questionable, problematic areas just listing languages; trying to standardize dialects and poorly documented ancient languages would likely standardize a bunch of errors and be useless.
Comment: A full list of world dialects with authority control serves as a useful index for digital linguistics research, besides Wikipedia.

Full list of ISO-639-6


Is this a very sloppy holding pattern or something else?

Question: This scheduled Belavia service to Barcelona appears to be in a very sloppy holding pattern where they aren't correcting for wind at all. Is it normal for a passenger jet to fly like this?
Answer: It does indeed look like they are not correcting for wind. The current wind over Belarus at 10km altitude looks like this:

(screenshot from windy.com)
That is consistent with the direction in which they are drifting. Such a flight path is not a normal holding pattern, which is based on a holding fix. While wind might push the aircraft somewhat off the nominal racetrack pattern, they would at least regularly overfly this fix (although modern RNAV systems are pretty good at compensating for wind).
I can only speculate on why they are flying like this. Most likely they are not holding at a specified fix. They might have been instructed to hold at current position by ATC, probably while they figure out if they are still allowed to fly into the EU, after the European Council has called for a ban:

The European Council:

[...] calls on the Council to adopt the necessary measures to ban overflight of EU airspace by Belarusian airlines and prevent access to EU airports of flights operated by such airlines;

(europa.eu)

Update: It seems they are returning now:

(flightradar24.com)
Comment: *They might have been instructed to 'hold at current position' by ATC* -- most likely *orbit left*. In a Boeing for example *attitude hold* in a bank does the trick. Related though yet unanswered: [Why did BA 199 fly a missed approach followed by circles?](https://aviation.stackexchange.com/q/66257/148977)
Comment: @ymb1 Never heard *orbit left* before, but that sounds like what they're doing. I'm not super familiar with the E-Jets, but as far as I know they don't have an *attitude hold* mode. There is a TCS (toch control steering) button on the yoke, but according to the [Auto Flight System description](https://www.smartcockpit.com/docs/Embraer_190-Automatic_Flight_System.pdf) that is only for overwriting pitch. Lateral control resumes when releasing the button. No idea what modes they used.


How Does the Propagation of H-pol E-M Fields Compare to That of V-pol E-M Fields (other things equal)?

Question: A rather popular belief on this topic is that h-pol is superior to v-pol.  Probably that is traceable to published "far-field" patterns over a lossy ground plane generated by Method of Moments software such as NEC (Numerical Electromagnetics Code).  This post is a deeper dive into the topic.
Comment: Would the downvoter please explain why?
Answer: As clearly shown in the graphic clip first below, h-pol e-m waves radiated at low elevation angles tend to be canceled by their reflections from the Earth near the antenna site. Note the last sentence in the text column at the right side of that graphic. (This clip is taken from a textbook printed in the 1940s, but Physics hasn't changed in the interim.)
The graphic second below shows a NEC4.2 comparison of the E-fields existing over a zero to 45° elevation sector, 0.1 km downrange from an h-pol and v-pol radiator both radiating 100 watts.  (Note that an h-distance of 0.1 km from these radiators lies well within their far field.)
The reduced fields from the h-pol radiator are clearly evident.
Comment: Downvoting a question without explaining why that was done doesn't advance the knowledge that could be gained by the author of the question, or its readers. Neither does it encourage the continued participation of that author in this Forum.
Comment: What does the horizontal axis of the NEC4.2 plot represent, and what are its units please?
Comment: It shows the value of the E-field at those "Z" elevations above the Earth, at a distance of 0.1 km.  For example, the E-field from the vertical monopole at an elevation of 40m AGL and a range of 0.1 km from the antenna is ~ 406 mV/m.
Comment: Your NEC4 graph says E(theta) on the top left, but for an Hpol source you want E(phi). Or are the red and blue graphs each for different field components?
Answer: I think frequency band and application need to be considered as a context.

Satellite signals get randomly repolarized as they travel through the ionosphere, so I don't believe there is any advantage to one orthogonal polarization over another (e.g. horizontal vs. vertical, right-hand circular vs. left-hand circular, etc.)

UHF and higher radio waves in urban areas are subject to extreme multipath scattering  that also tends to randomize polarization.


Cut off part of other shape

Question: So I have a rounded rectangle and a parallelogram. The parallelogram is inside the rounded rectangle, but part of it is sticking out of the rounded rectangle. How do I cut off this portion of the parallelogram in Photoshop CS6?
Answer: If these are vector shape layers, you can set the top layer (the parallelogram) as a clipping mask.
Select the top layer and click Layer > Create Clipping Mask, or alternatively Alt+click between the two layers.
Here's the result:
Answer: If you are sure that there's no need to resize or to move the shapes to different relative positions, then

have the shapes in different layers as raster images
select the exterior of the blue shape
goto the layer of the black shape and press DEL

This is the easy way. If you want to retain the editability, the complexity builds up. Yöu need masks and smart filters. You can keep it simple and still editable, if you save the original shapes in invisible layers.
Not asked, but good to know: Working with shapes is much more flexible in Illustrator or other vector drawing programs.

Cut off part of other shape


Why does my iPhone heat when charged and when in use

Question: My iPhone gets really hot when charging and sometimes when I use it. I thought it might do this because my iPhone is cracked and I've thought about getting the screen fixed but I'm not sure if that's the reason why it's hot. I have also stopped using, I haven't used it for a few weeks now but it still heats up when I charge it. What can I do to resolve this problem?
Comment: All phones heat when charging - have you compared the heat your phone generates with another or considered just taking it in to a shop to have someone that works with hardware make sure yours is safe to use?
Comment: My iPhone will get really hot while I'm on the internet or even texting. It just started doing this I've only had it for about 2 months.
Answer: 1. Bad Connection
In areas with poor or reduced connectivity, iPhone has to expend more time searching for and maintaining network connections. This in turn uses more energy which causes the battery to heat up.
Possible Solution
You can try turning Airplane Mode on and see if you have the same problem with heating up.  I also have an iPhone and I myself notice that it does not heat up if I am out in the open, but it heats up and drains the battery if I am in the basement of a large concrete building.
2. Case?
If you have a case for your iPhone, you should expect that it heats up. The case, while it does protect your phone, also blocks some air from coming out and consequently causes the hot air to be trapped inside the phone. This will cause your iPhone to heat up almost indefinitely.
Possible Solution
When you are charging your iPhone, take it out of its case. While this may be inconvenient, it will help.
3. CPU Usage
If your phone is heating up, you may have a lot of applications open. Also, if you were playing a lot of games, then you can expect an increase in CPU usage and temperature as well.
All of the listed items below can contribute to an increase in CPU Usage:

Games
Data Usage (Facebook, Emails)
Fetch/Push Data

Possible Solutions

Do a Network Connections Reset (Go to Settings => General => Reset => Reset Network Settings, then reboot (you will lose WiFi passwords)

Try disabling the following apps (in Settings => General => Restrictions): Multiplayer Games, Ping, App Store, iTunes Store. Then reboot.

4. Defect
If nothing else works, then it is also quite possible that your iPhone is defective and if this continues to occur as you have stated, I would take it to an Apple Store. They may be able to better diagnose the problem.
Links and Resources
MacRumours
Apple Discussion Board
Apple Discussion Board
Answer: My iphone gets hot too, take out the case, it may help.
When I take out my case, my iphone isn't that hot. Some cases trap the heat while it is charging, therefore the iphone will get hot.
Answer: This IS normal and happens to my iPhone all the time. However you might want to take it to the apple store to check if there is a problem. If there IS a problem on software then Apple will replace your iPhine.
Comment: Apple generally won't perform a hardware repair on a software problem. Perhaps you meant to say something different than what you wrote?
Answer: Cases and Charging
Charging your iPhone while in certain carrying cases may generate excess heat, which can affect battery capacity. If you notice that your iPhone gets hot when you charge it, take it out of its case first.
Comment: Can you provide some data to show that?
Comment: data ?
http://www.apple.com/tr/batteries/iphone.html
bottom right corner of page.
Comment: and... the [English version](http://www.apple.com/uk/batteries/iphone.html)
Answer: My iphone 4 started getting hot and would not hold a charge after I made an update.  I suffered with this for about 2 months until I got in contact with the iphone company and finally talked to the right person to fix both the getting hot and the battery charge problem.  Here is what you do:

Go to Settings
Go to General
Click on Reset Network Settings
Exit the app
Turn off the iPhone
Wait for 5 seconds
Turn your iphone back on. YOUR PROBLEMS ARE SOLVED!
Answer: try taking it apart and cleaning any dust or dirt off the logic board then put it back together. I did that to mine it worked fine
Answer: DO NOT USE Rechargable cases.
if you use your display colors will be suck as my iphone.
do not charge using recharable cases if iphone battery is low (%20-%10).
after 20-30 charge your iphone display color tone will be pink on the middle of the screen area. and I know you wont want this.
best method is
Im warning you -do not use rechargable cases-
first of all chage using cable %70-%80, than you can continue charging using rechargable case without any heat.if you dont do that you will see a pink display area on your screen.after a while. (within 2-3 months)
Answer: I have an iPhone 4S and it has a crack on the back on the right hand side, away from the camera.
My phone heats up as well when charging the solution is:
When you are charging the phone put the screen face down on a table and let it charge that way it won't heat up.
Answer: charge through ur PC/laptop, wont heat up that much
Answer: Too much stuff in one time that's why I had to reset all my things and it works and it's all saved and even though my iphone is cracked when it's charging so it will work I promise
Comment: Hi and welcome to Ask Different. Posting in the answers section is specifically reserved for posting direct answers to the question being asked. The Stack Exchange Q&A format is different from your typical forum, it's not meant for discussion. For more information please see our [Help section](http://apple.stackexchange.com/help). Consider deleting this as it will likely continue to attract down votes for not being a direct answer to the question or improving it to be a direct answer.


What is the IPA of the two-syllable r sound in English?

Question: For example, the word "Emperor" in IPA on Wiktionary for General American is written /ˈɛmpɹɚ/. But that's kind of cheating because ɚ is basically /ɹ/ as far as I can tell. Yet, when you say the word, you say it in syllable form "em-pr-r", it's almost as if there is a silent or subtle glottal stop as in /ɛmpr'r/. Are /ɹ/ and /ɚ/ not really the same sound? To me as an American English speaker they sound the same. How can this word (or words like horror, mirror, etc.) be represented in IPA most accurately to account for the two-syllable "r" sound? Is it about stress somehow?
Comment: Are you asking about the _phonetics_ or the _phonology_?
Comment: After thinking about it more I want to say there is an "oo" sound as in "book" in between, because the shape of your mouth changes slightly to that shape, but it is only a tiny bit different than the r shape. Causing a slightly change in intensity of the r.
Comment: @hippietrail I'm American, and I find that when I say a word like "mirror" or "horror," my tongue, lips and jaw all open slightly in between the first /r/ sound and the second one, producing a little bit of an audible separation between the two sounds.
Comment: Since American /r/ is rounded, any reduced vowel between /r/'s in _mirror_ or _emperor_ is going to be rounded, too. It's probably a very short centralized [ʊ]. Good observation, Lance. Have a look at Ian Catford's _Practical Introduction to Phonetics,_ which is full of little experiments like you describe.
Comment: If it's an 'r' sound followed by an 'r' sound and there's no vowel between, then what *is* between? I'm an Australian English speaker so can't introspect. Is there any kind of hiatus, is there just a long syllabic 'r'?
Comment: @LancePollard: Interesting. Unfortunately (for me) the vowel sound in "roof" is one of the key differences in our dialects. To us it sounds somewhere between the vowel in "rough" and the schwa. I would generally describe any indistinct vowel sound like this in English as a schwa (but I'm not a real linguist).
Answer: Since you tagged this "phonology" rather than "phonetics":
There are a few different ways of representing the second syllable of words like "mirror" in rhotic dialects. Some people treat it as a combination of a vowel /ə/ and a consonant; other people treat it as a syllabic resonant /ɹ̩/. (The same goes for the second syllable of "written", "little", and so on.)
If you prefer the first option, "mirror" would be something like /miɹ.ɹəɹ/, with the schwa acting as the nucleus of the second syllable. If you prefer the second option, it would be more like /miɹ.ɹɹ̩/, with the resonant itself being the nucleus.
Phonetically, if I'm pronouncing the word slowly and carefully, I do tend to have something closer to a schwa in the middle: my tongue lowers slightly, then rises again for the final [ɹ]. If I'm speaking quickly, though, there's no separation between the two [ɹ]s: the realization is more like [miɹː] (contrasting with "mere" [miɹ]). It's possible you actually have a glottal stop in the middle there (though I certainly don't), but the only way to tell would be a recording.
Your example word "emperor" is a bit trickier than "mirror" because there are a few different ways to pronounce it: some people say it with two syllables, others with three. (Personally, I tend to go with three.) I would transcribe these as /ɛm.pɹɹ̩/ versus /ɛm.pɹ̩.ɹɹ̩/—or, if you like schwas, /ɛm.pɹəɹ/, /ɛm.pəɹ.ɹəɹ/. Either way, it has the same /ɹɹ̩/ sequence as "mirror", in my dialect, with the same possible realizations (a slight tongue lowering if pronouncing it slowly and carefully, otherwise just a lengthened sonorant).
Comment: @hippietrail Yeah, that sort of relaxing is what I mean by the schwa in careful speech. And I disregarded vowel length here (since the consonant's what's important), but you're right, it should be a long i: before a voiced consonant.
Comment: @hippietrail For AmE, it's very common to only describe tense/laxness and not vowel length, so _seat_ is /sit/ while _sit_ is /sɪt/. This is much less common outside AmE.
Comment: Wow I was not aware American English had a short 'i' in 'mere'. In the non-rhotic Englishes I know better 'i' can never be short before 'r' word-finally, though it can word-internally like in 'squirrel'. Also, isn't there another kind of hiatus than a glottal stop? I find it hard to imagine anyone fully closing their glottis Cockney-style in such words, rather than just a kind of relaxing/easing/centering.
Comment: @JanusBahsJacquet: Ah yes I usually only get confused when it's all in ASCII but here where Unicode IPA was liberally used it really shouldn't have stood out to me. Thanks for the reminder.
Answer: If you look at official IPA charts (here, here), you won't find the letter /ɚ/ anymore. Esling's chart (the second of those) exemplifies the rhoticity diacritic on regular schwa (ə plus rhotic-hook, i.e. [ ə˞ ], analogous to [a˞] and so on. All that means is, "whatever the vowel is, plus a rhotic quality", which can be any kind of rhotic articulation. However, [r, ɹ, ɻ, ɼ, ʀ] are more-specific rhotic consonants. One essential difference between <ɹ> and <ə˞ > is the the former is a non-syllabic consonant. That can be remedied by writing it as <ɹ̩> (with the syllabic diacritic). However, there is a further claim implicit in writing <ə˞ >, and not as <ɜ˞>, which has to do with the purported tongue position: the latter is a rhoticized open-mid central vowel and the former is a mid central vowel.
Now that we have the "semantics" of the letters out of the way, the next question should be which is most appropriate. One criterion is phonetic. In writing <ɹ̩>, the phonetic claim is that the thing is phonetically the same as <ɹ>, except for syllabicity. That is almost reasonable in my dialect except that  <ɹ> is much constricted (the tongue is higher) than supposed <ɹ̩>, so writing the rhotic vowel as <ə˞ > is more phonetically accurate, again for my dialect. I would not be surprised to hear that in rhotic UK dialects, <ɜ˞> is more accurate as a phonetic claims.
But as a phonological claim, I think that /ɹ̩/ is more accurate: it is /r/ which has been made the syllable peak, by deletion of /ə/. It is analogous to syllabic [n̩, m̩, l̩]. On the third or fourth hand, there are many dialects of GAE. In my dialect, "tear" (the verb) and "terror" are a durational minimal pair, likewise "bear" and "bearer", which can lead to some degree of hilarity when context fails (horror and whore). A phonological analysis as [hɔɹ] and [hɔɹɹ̩] is good enough, by my standards, but if I am being very phoneticky, I would write [hɔɹ] and [hɔ:ɹ]. As you should be able to see, that has major consequences for how you write the tense/lax ~ long/short distinction (seat, sit). I do know that some speakers, from Upstate New York, are or were mildly surprised at the [hɔɹ], [hɔ:ɹ] minimal pair: not everybody talks the same as me. In unstressed syllables, I suspect that /əɹəɹ/ just becomes [əɹ] and "tamper" and "tamperer" are actually pronounced the same, although I can certainly over-articulate the syllables to make a distinction.
In other words, accuracy can be judged according to a physical standard, and a cognitive standard, and they don't yield the same results. It depends on what thing you want to "accurately represent".


PSN login issues

Question: So I have two PS3s in my house.
One belongs to my brother. He bought his PS3 from another person and I reset his system so that he can have his own account on the PS3. We set up his account online but it was not working so we used my information. I did not know that having both systems on the same account would be logging me off on my system. So I looked up how to change the account on the system to his own. It worked but that's because I logged out of my account and switched it. My PS3 system logged me out of the PSN also.
I can't log in, I've tried multiple times and I can't even change my password. I tried changing the password on the PS3 but it's saying my information is not valid. Then I tried using my PC and my phone, but I have not received an email. I cannot get anyone from customer service to help because of the COVID-19 pandemic.
Please help, I do not know what to do. Now my brother can't even log into his PSN.
Answer: If tou are sure that credentials to your account were not be changed, probably the only way is contact with Sony Playstation's Support.

PSN login issues


Is a flattening rank a lower bound for the border rank?

Question: Suppose $T \in V_1 \otimes \cdots \otimes V_k$ is a tensor, where each $V_i$ is a finite dimensional complex vector space. A $1$-flattening (or a flattening) is a realization of $T$ as a matrix in the space of matrices in $k$ essentially different ways as follows:
\begin{equation}
V^*_{i} \rightarrow V_{1} \otimes \cdots \otimes V_{k-1}.
\end{equation}
Is it true that the rank of a flattening of $T$ is always a lower bound for the border rank of $T$? If not in general, is it true when $T$ is a symmetric tensor?
Answer: Yes, the flattening rank is a lower bound for border rank.
First note that flattening rank is a lower bound for rank. If $T$ is a decomposable tensor (simple tensor, rank one tensor) then every flattening of $T$ has rank one. If $T$ has rank $r$, then $T$ is a sum of $r$ decomposable tensors, and so every flattening of $T$ is a sum of the corresponding $r$ flattenings of decomposable tensors. Each of those flattenings has rank $1$. A sum of $r$ linear maps of rank $1$ has rank at most $r$, so every flattening of $T$ has rank at most $r$.
Now, the set of tensors of border rank less than or equal to $r$ is the Zariski closure of the set of tensors of rank $r$.
(A digression: This is the $r$th secant variety of the variety of decomposable tensors, i.e., a Segre variety—at least if you set the $k$th secant variety of a variety $X$ to be the closure of the union of $(k-1)$-planes spanned by $k$ points of $X$. In this numbering the "ordinary" secant variety of lines is the $2$nd secant variety. ... At some point in writing this I have rather glossed over any distinction between affine varieties, such as sets of tensors, and projective varieties. But it doesn't matter much for discussions of rank—all the sets of tensors here are cones, so they might as well be projective varieties.)
On the other hand, the set of tensors with flattening rank less than or equal to an integer $k$ is also a Zariski closed set. Indeed it is defined precisely by the vanishing of the $(k+1) \times (k+1)$ minors of the flattenings. (I am being intentionally vague as to which flattenings. You may decide if you want to consider $1$-flattenings only, or all flattenings $V_I^* \to V_{[n]\setminus I}$ for $I \subset [n]$, where $V_I = \bigotimes_{i \in I} V_i$, etc.)
Putting it all together, the set of tensors of (ordinary) rank less than or equal to $r$ is contained in the set of tensors of flattening rank less than or equal to $r$. The latter is Zariski closed. Therefore the Zariski closure of the first set, the set of tensors of border rank less than or equal to $r$, is also contained in the set of tensors of flattening rank less than or equal to $r$. This is just to say that if $T$ has border rank $r$ (or less), then the flattening rank of $T$ is also less than or equal to $r$. Hence yes, as you asked, the flattening rank of $T$ is less than or equal to the border rank of $T$.
It is also true for symmetric tensors with (symmetric) border rank, either by the same argument, or by an inequality between symmetric border rank and (ordinary, non-symmetric) tensor border rank.
Some introductions include Landsberg, Tensors: Geometry and Applications (bonus: has a ridiculous drawing of a pickle) or Carlini, Grieve, Oeding, Four Lectures on Secant Varieties (no pickles).
Comment: Thank you Zach! The $n$-tuple of $1$-flattening ranks is the multi-linear rank $r_i$ of the tensor $T \in \bigotimes_{i=1}^n V_i$. In Landsberg's book, the Zariski closure of all tensors of multi-linear rank $(r_1, \cdots , r_n)$ is called the subspace variety $\text{Sub}_{r_1, \cdots , r_n}$. In exercise (5.11) of your 2nd reference ([here](https://arxiv.org/pdf/1309.4145.pdf)), the $r$-th secant variety $\sigma_r(X)$ of a Segre variety $X$ (the space of tensors with border rank no greater than $r$) is contained in the Sub$_{r_1, \cdots , r_n}$, IF $r \leq r_i$. Am I missing something?
Comment: No, I don't think you're missing anything. Say $T$ is a tensor of border rank $r$. Then the $1$-flattening ranks $r_i(T) \leq r$. If $r_1,\dots,r_n$ are integers that are $\geq r$, then $r_i(T) \leq r_i$ for each $i$. So $T \in \operatorname{Sub}_{r_1,\dots,r_n}$.


Sorting column A with drop-down and column B with checkbox

Question: I have a spreadsheet that I use to run a foosball tournament, and in column A I have a dropdown data validation that will let me select a players name. In Column B I have a checkbox that I check once a player has paid their entry fee.
I have another column in the sheet that takes the values from column A and sorts them into player/teammate, and in order to get a randomized team, I select all players in column A and do a randomize sort on that range. However, the checkbox in column B does not follow where the data in column A goes, mixing up who has paid and who hasn't.
Is there a way to make it keep column B selection matched up with the player name in column A?
I have searched quite a bit on this but haven't come across anything helpful.
Comment: Welcome. What web application are you using?
Answer: option 1:
=QUERY(SORT(INDIRECT("A1:B"&COUNTA(A1:A)),
 ARRAYFORMULA(RANDBETWEEN(ROW(INDIRECT("A1:B"&COUNTA(A1:A)))^0, 100)), 1),
 "where Col2 is not null")

option 2:
=ARRAYFORMULA(IFERROR(VLOOKUP(D1:D, A1:B, 2, 0)))


Show that the series is divergent

Question: I have the following series:
$$
    \sum\limits_{n=1}^{\infty} \frac{\sin(n)}{3n^p-\sin(n)}
$$
and I want to show that this series diverges for $0<p \leqslant \frac 1 2$. I tried to write
$$
   \frac{\sin(n)}{3n^p - \sin(n)} = \frac{\sin(n)}{3n^p} \left(1-\frac{\sin(n)}{3n^p}\right)^{-1} = \frac{\sin(n)}{3n^p}\left(1+\frac{\sin(n)}{3n^p}+\cdots \right) \\
 = \frac{\sin(n)}{3n^p} \left(1+\frac{\sin(n)}{3n^p}+\cdots+\frac{\sin^k(n)}{(3n^p)^{k}} \left(1-\frac{\sin(n)}{3n^p}\right)^{-1}\right) \\
= \frac{\sin(n)}{3n^p} + \frac{\sin^2(n)}{(3n^p)^{2}}+\cdots+\frac{\sin^k(n)}{(3n^p)^k} + \frac{\sin^{k+1}(n)}{(3n^p)^k \bigl( 3n^p-\sin(n) \bigr)}
$$
and then choose for any fixed $p$ such $k$ that $pk > 1$ so that the series related to last term converge. The series related to first term converges for any $p>0$. So there is a problem to show that the series, related to group of terms from first to $k$-th diverges. For each of these terms I can show this by expanding $\sin^m(n)$ as a sum of sines and cosines in first power and constants. But how can I show that the resulting sum will correspond to an also divergent series? Maybe there is some better way to show that my series diverges?
Comment: The terms with odd $k$ converge (by Abel-Dirichlet), the terms with even $k$ are positive, so it's enough to show that the $k=2$-part diverges. For that one needs to show that even if you remove $n$'s with $\sin^2 n<\epsilon$, the harmonic series is divergent. It seems 'obvious', but I needs a proof.
Answer: Summation by parts gives the convergence of $\sum_n\frac{\sin n}{n^p}$, so we have to deal with the convergence of $\sum_n a_n$, where $a_n:=\sin n\left(\frac 1{3n^p-\sin n}-\frac 1{3n^p}\right)=\frac{\sin^2n}{3n^p(3n^p-\sin n)}$.
We have a series with non negative terms, and $a_n\sim\frac{\sin^2n}{9n^{2p}}$.
Rewriting $\sin^2n$ as $1-\cos(2n)$ (up to a multiplicative constant), noticing that $\sum_n\frac{\cos(2n)}{n}$ is convergent and $\sum_n\frac 1{n^{2p}}$ is divergent, we conclude the divergence of the initial series.

Show that the series is divergent


On back-end, trying to use Assets loads my homepage on the Assets box!

Question: I have an Assets field on my site. When I click to upload files, the assets box opens as it should, but displays my homepage. Any ideas?
Answer: Update: based on your comment that you've got a multiple sites installed on the same server:
Make sure the correct system dir is being specified in your index.php and admin.php files, and that you've got valid values for $config['base_url'], $config['site_url'], and $config['cp_url'].
====
An over-ambitious .htaccess re-write rule is commandeering the ?ACT= request, and redirecting the URL to the homepage, perhaps?
Should be easy to test; comment out and/or remove the .htaccess rules, if possible, and see what happens.
Comment: I thought of that and started deactivating .htaccess rules, but to no avail. If it helps, this site is in a subdirectory of another site. The main site has Assets used in the same way and it works fine. The subdirectory site is the one with problems. I tried deactivating both .htaccess files.
Comment: I don't know if this will help, but the site in the subdirectory was not installed from scratch, but is a copy of the main site which I copied to the subdirectory, so there may be a setting that has not been updated?
Comment: Updated my answer to check some paths/config values.
Comment: system dir is correct in index.php and admin.php. In the config.php file, $config['cp_url'] is correct, $config['base_url'] is set to blank ("") and $config['site_url'] is nowhere to be found...
Comment: This definitely is a case of an Assets AJAX request being redirected somewhere.

Are you using 301 redirects in .htaccess? Those will drop all POST data and Assets uses POST exclusively in AJAX requests. Have you tried the assets_site_url setting?(http://docs.pixelandtonic.com/assets/using/config.htm)
Answer: Do you have an index.htm page in your site root? That can cause a similar issue for Assets.
Try adding this config line to your config.php to tell Assets the path to your site index:
$config['assets_site_url'] = "/index.php";
Answer: Issue solved. The path in "URL of Upload Directory" under File Upload Preference was set as an absolute path for some reason. I changed it to an relative path and it now works.


Stringing during travel on first layer with Ultimaker Cura

Question: I'm using Ultimaker Cura 3.6.0 and I am getting some annoying "stringing" on the first layer. This isn't new to 3.6.0 as I have seen it on pretty much every version I have used.
What appears to be happening is that as it is laying down the first layer, it doesn't retract as it moves from one area to another. This leaves a trail of filament which then shows up as an unattractive line embedded in the print. (ignore the other extrusion issues in the example below)
A similar thing happens on the top layer. It ruins the look of the nice smooth bottom I get from a glass bed.
I don't have stringing issues elsewhere on my prints.
I thought at one time I had seen a setting to control it, like "retraction during travel" or something, but now I can't seem to find anything that sounds like it in the dizzying array of settings.
Does anyone know of a way to get rid it these lines?
Answer: Yes, if you are using the Combing Mode option, please ensure it doesn't do this in the skin, for a leak/string free first layer, it is required to set the Combing Mode to Not in Skin.

When the mode of the option is set to Not in Skin, combing is "off" for the skin; this implies that the material will retract and move in a straight line to the next print area. When material is retracted (and when properly tuned for your printer), the nozzle will not leak filament causing those (deposited) travel movement lines as indicated by the OP.
Comment: Combing. No wonder I couldn't find it on a search for "retract" or "travel". :-) I'll give that a shot when I get home tonight.


Are there examples of mutants or meta-humans who live normal lives?

Question: I was thinking about the upcoming Avengers vs X-men (not X-men vs Avengers!), and mutant registration. One thought led to another and I was wondering if any mutants or meta-humans exist who aren't super heroes? It doesn't matter if the 'powers' or 'abilities' make them crime fighting potential or not, I'm just wondering if they exist?
Comment: @Wikis Batman is the *exact opposite* of what I'm after. He doesn't have powers but he does fight crime. I'm looking for comic book characters who have powers but don't fight crime/do have normal lives.
Comment: Oh... :) note to self, learn to read *before* reacting...
Comment: So I guess you are limiting this to the Marvel universe, thus excluding the most obvious candidate: Batman.
Answer: I hope I'm reading the question correctly...
To point out the obvious, there are plenty of super villains, which would qualify, but I suspect you're actually looking for meta-humans that are simply living out normal lives, and not getting involved in the struggle.
In that case, there are plenty of examples of super-powered beings that might qualify.  It's been years since I read comics, but I remember the Morlocks in the X-Men series living out their lives underground until the Marauders came in and slaughtered a bunch of them.
There have been others that various super teams have run across that seem to want to live out a normal life, but get sucked into one adventure or another, simply because their powers either make them a target, or get them in trouble, or some superhero team simply encounters them, they play a minor role in a storyline, and are rarely seen.
I don't know whether you'd count these as superheroes, given that they only interact with active heroes/teams by chance, yet they often perform heroic (or anti0heroic) acts in these story lines.
Various superheroes also try to leave the hero business and live a normal life, but they invariably seem to get sucked back in for some reason or another.  Circumstance and moral character usually combine to provide a situation where their conscience can't let them sit idly by.
I'm sure there are others out there that have never "gotten involved'.  The problem with identifying all of them is that if they didn't meet one of the above situations, they wouldn't likely have a reason to be included in the comic at all.  Why would the author identify a super-being without reason?
Comment: I'm considering it from the point of view that they might be made victims of the registration system.
Answer: There are a large number of mutants in the Marvel Universe (back when there were a large number of mutants, at least) who's mutations don't do anything but change their physical form (such as being exceptionally hairy) without conveying superhuman abilities.
The majority of these mutants simply try to live a normal life.  You'll see them in the background (and sometimes foreground) of x-men comics, especially when they're discussing anti-mutant bigotry or actions.
The Friends of Humanity on the 90s X-men cartoon seemed to love to target these guys.  In particular there was one stock background character who's mutation was to be exceptionally hairy (shown by a full beard, somewhat disfigured (hands were unusual looking, fairly ugly by typical standards), etc.  He got picked on a lot, but had no special powers.
These characters don't usually feature in the comics, except as victims - lacking useful powers or abilities, they simply lead normal(ish) lives - this does not usually make for interesting stories.
Answer: I think it depends partly on how you define fighting crime, and how loosely you're willing to go in terms of "normal". Since you tagged it Marvel, the best I can think of is maybe something like Marshall Law...which was technically Epic, but Epic was/is a Marvel imprint.
If you're willing to look outside of Marvel, and can more clearly define how normal you want their lives to be I can probably do much better.
EDIT: A cursory Google search turned up a Marvel series called Loners - which I'm not familiar with - that might fit with your criteria.
Answer: Sentry is a super hero with the power of a Million exploding suns but has to cope with agoraphobia and the fear that he'll lose control of his powers. He eventually overcomes this, but until then he just lives a normal life in his cabin with his dog.


Alternative to URLDownloadToFile function

Question: Are there any alternative to the URLDownloadToFile function? I cannot download anything from an HTTPS server with invalid certificate. Are there any generic HTTP clients which I can use to download a file from an HTTPS server with an invalid certificate? Are there any other alternatives for this situation? Thank you!
Answer: You can try libcurl, a easy-to-use client-side URL transfer library.
Here talks about how to deal with ssl cert with it.
Comment: I ended up doing it like this: http://www.codeproject.com/Tips/314167/Alternative-to-URLDownloadToFile-function
Answer: Try using CInternetSession::OpenURL. I'm not sure if it helps with your problem with invalid certificates, but you were asking for alternatives to URLDownloadToFile.
    CInternetSession connection;
    CStdioFile* stream = connection.OpenURL("https://www.google.com");

    const int capacity = 10000;
    char* buffer = new char[capacity];
    int bytes_read = stream->Read(buffer, capacity);

    FILE* output = fopen("C:\\output.html", "w");
    fwrite(buffer, 1, bytes_read, output);
    fclose(output);


Is Sadler's 2000 book Queen's Gambit Declined focused on white or black?

Question: I'm looking for QGD repertoire book as Black. Would Sadler's Queen's Gambit Declined fulfill this, or is it focused on White?
Comment: Nils Grandelius has a chessable course called 'Magnus Queen's Gambit' , a modern way of playing QGD
Comment: @Anna In addition to cmgchess' suggestion, "The Queen's Gambit Declined: Move by Move" could be a good - this series tends to focus more on explanations of plans and such. If you're more advanced and care more about the theory itself, there's "Playing 1.d4 d5: A Classical Repertoire". These books are both from 2017, so while not cutting edge they aren't too old either.
Comment: @Beginner  I'm not below 2000 Elo, apologies if I gave this impression
Comment: Any opening book that is more than 20 years old is really only of interest or use to chess historians. Theory moves at far too fast a pace for you to be able to rely on lines in books that old.
Comment: Thank you, I don't usually play Queen's Gambit so I didn't know. I've just heard a lot of praise for this particular one. What "modern" book would you recommend for QGD as black?
Comment: Thank you for the book recommendations, I'll check them out!
Answer: I got pointed to this topic by a friendly chatter at the TCEC. In principle, Brian is absolutely right - an opening book 20 years old is really going to be missing some stuff and certainly won't give you the complete modern picture of the opening. In the specific case of the QGD book, there are some parts of my book that are still relevant and still very useful - in particular about the typical pawn structures that you can encounter in the opening. I once had the privilege of studying for a couple of weeks with the great trainer Mark Dvoretsky and he gave me an amazing overview of how to play the Carlsbad structures from both sides (when White plays cxd5 and Black replies ...exd5). That went into the book, and I think it's timeless advice! Whatever you do, you should get a modern course as the basis, but if you're looking later for some extra insight into typical positions (maybe once you've got all your lines sorted out) then this is one of the extras you could think about! Hope that helps! Best Wishes, Matthew
Comment: Welcome to the site, it's an honor to have you here! Thanks for your answer; you might want to have a look at the [tour] and our [help] to get a feeling for where we differ from a traditional chess forum.
Comment: Thank you very much! I ended up picking up your book as well as Ntirlis' d4 d5 repertoire book, and have been enjoying the clear Q&A format of insights greatly so far.
Comment: Ah great - I was going to add a comment recommending the Ntirlis book so I think you've made an excellent choice! :) Best Wishes, Matthew
Answer: I haven't read the book but from a quick view at the first few pages it looks like it comes from a White perspective, at least when it comes to "completion" (it covers several options for Black from the same position, while it sticks to one recommendation for White).
This doesn't mean the book is useless if you want to study the QGD for Black though. It can give you an overview and some examples of the options you have and help you choose the most practical one.
As for the opinions that old opening books are not useful anymore today, well, it depends. Some lines may be outdated and need revision or further analysis if you want to play them at stronger levels, but you can still get a lot of knowledge about common themes and middlegames arising from the QGD. At lower levels you may even do well with theory that is a century old specially considering the QGD does not rely on too many "critical" lines.
For instance, in the QGD, you'll find much more use in learning how to play isolated "d" pawn positions and Karlsbad structures than in studying the exact best continuation in most lines. It all depends on your level though, could you give us an approximation of your current Elo?
Comment: Thank you! I've been browsing through Sadler since I asked the question, and found that the book contains many useful paragraphs on high-level ideas and structures. It seems focusing on those is the best use of the book, and getting my repertoire from elsewhere? I've been looking at Nitrlis' 1. d4 d5 book. My FIDE Elo is 2050.
Comment: @Anna our ratings are pretty much the same so take my advice with a grain of salt but In my experience I'd say yes, at first take as much knowledge about general plans  so when you finally start building up the lines in your repertoire, most of the moves will already feel natural and you'll get the same results with less work. I'm no expert in 1.d4 d5 so I can't tell if that book is the best option, but the themes of the QGD are common and you'll find many of them in most middlegame strategy books. I do have some stuff on the Catalan though, so if you're interested we can trade some materials
Answer:
@InertialIgnorance gave you excellent advice. I agree that the "Move by Move" series is excellent. Without a doubt, start with "The Queen's Gambit Declined: Move by Move, by Nigel Davies." About your question, Matthew Sadler is a genius! And the book won the Book Of the Year award in 2000 from the British Chess Federation. How can you go wrong with that? Of course, when a book is not new, learn ideas, not moves. Also, evaluate the lines using Stockfish because sometimes an important detail has not been analyzed. This trick works for old and new books as well. About another part of your question, Sadler authored the book taking into consideration both sides. He gave ideas for White and Black. At the end of each chapter, he made a summary. The image that is above is a good example that he took both sides into account.
However, the study of openings is one of the most difficult parts of chess training. I suggest my students focus on strategy, tactics, and endgames, unless they are fighting for the international master or the grandmaster title.
For openings, I suggest to my students that AFTER they finish their games to compare their moves with the suggestions that are in Nunn's Chess Openings. It is an old book, but good enough for players that have less than 2000 ELO rating points. You can find used books of this kind on eBay for $10. Nunn's Chess Openings has almost all the possible openings that exist.
If your rating is above 2000, in addition to comparing your moves with Nunn's Chess Openings you should compare and analyze your moves with a chess trainer (some chess trainers charge only $10 per hour), and with the most modern version of Stockfish that is available for free in www.lichess.org Here is the link: https://lichess.org/analysis
It is important to notice that to get excellent quality in the analysis, you need to provide enough hardware and time to Stockfish.
Additionally, for openings, I like the books from this publisher: qualitychess.co.uk/sections/1/opening
One of my closest friends who is a FIDE Grandmaster and writes for the best chess magazines of the world suggested me Chess Publishing that has the best information for $19.50 per year: https://www.chesspublishing.com/content/7/index.htm
Chessable offers a thirty day money back guarantee. So, I suggest to try with Chessable. They also offer some free courses in the Queen's Gambit Declined: https://www.chessable.com/courses/s/Queen's%20Gambit%20Declined
I like also Modern Chess. They offer some free material that you can analyze. https://www.modern-chess.com/chess-databases?database_author=&database_opening=Queen%27s+Gambit+Declined&partner=
ChessBase has some good video courses as well: https://shop.chessbase.com/en/search?query=Queen%27s%20Gambit%20%20Declined&cat=0
New In Chess also has some good material: https://www.newinchess.com/catalogsearch/result/?q=Queen%2BGambit%2BDeclined
In addition to that, nothing better than studying chess in general, and openings, is to play the opening in correspondence chess with white and black pieces. Sometimes thematics tournaments are available. My favorite website is Lechenicher SchachServer, that is 100% free: https://www.chess-server.net/en/ Lichess also has correspondence chess.
Again, my advice is to prioritize endgames, strategy, and tactics, unless you are fighting for the international master or the grandmaster title. Good luck with your chess journey!


Stahara word usage

Question: In the 1920 text, Secrets of Jujitsu by Captain Allan Smith (the pdf is readily available by googling), Smith refers to the abdominal region as the "Stahara".  I've done some Japanese arts before, but have always heard this region referred to simply as the "hara".  After doing a search, the only usage of this word I've been able to find online is in reference to Captain Smith's text.  Is there some further connotation to using the prefix "Sta"?  Is this legitimate Japanese word usage according to the principles of Judo or Jujitsu?
Comment: Just to clarify, [下腹](http://dict.asia/jc/下腹) (したはら *shitahara*) is a word in Japanese, meaning "lower abdomen", and does occasionally occur in technical descriptions of throws in [Japanese](https://ja.wikipedia.org/wiki/隅返) and [Chinese](http://www.klnjudo.com/judo-awareness/else/judo-article-3.htm) [texts](https://books.google.co.uk/books?id=CHhBTwEUkmoC&pg=PA463&lpg=PA463&dq=下腹+柔道) on Judo, but purely as an anatomical term.
Comment: my coach was hiroshi nakamura, best japanese coach in all canada ... and he always yelled at when I was training : "Use 'Hara' thierry savard! ".

so I'd stick with it myself, since he learned in japan, I guess its refer this way over there too
Answer: In the text, he explains the origin of this term. And he points out that it's his word, not something the Japanese would say:

When I commenced to teach jujitsu in Yokohama, Japan, in every trick I
  showed how to use the lower abdomen, and how to maneuver opponent's
  balance. My first pupils were Japanese friends, and lower abdomen to
  them was shita hara.
Shita (pronounced sh'ta) and hara are two Japanese words meaning under
  or lower abdomen. The words shita hara mean to a Japanese what the
  words lower abdomen mean to us -- and nothing more.
This word hara is the same word we meet in hara kiri -- abdomen
  cutting -- the Japanese method of suicide.
Gradually as I evolved the idea of balance-control and abdominal power,
  I adopted the word shita-hara as a technical term for a new principle
  for which there was no name. When teaching the Doughboys, they called
  it "Stahara" and that is how it was finally written. It is an American
  word for an American idea.
STA-HA-RA Sta -- pronounced as in star.
  ha -- pronounced as in harp.
  ra -- a has the same sound as in the first two syllables.
  Japanese teachers of jujitsu do not mention the Stahara when explaining
  a throw or trick to their disciples. They teach the use of the arms and
  legs, of the hips and shoulders, but do not show the principle of
  balance, which is the basis of the whole system.
It is therefore an average of ten years before a student of jujitsu in
  Japan masters these throws. It takes that length of time to acquire
  the scientific way, in common parlance, to "get the knack" of doing
  the trick.
Jujitsu is not done with strength of arm or leg and this inability to
  grasp the underlying principle is why it takes so long to master it.

This seems like a reoccurring theme in West meets East. Some Western guy (this guy happens to be from the U.S.) goes to Japan and is taught whatever the Japanese feel comfortable teaching him, and do so while having communication problems. He tries it and finds out it's really hard. After being thrown around and joint locked a lot, he learns some things, but he's still frustrated by how bad he is and how good everyone else is.
Then one day he's sitting around sipping on some rice wine while eating his sushi when it comes to him. It's some brilliant, much better way to think of jujitsu than what he was taught. So now he thinks he's just figured out the secret to jujitsu that the silly Japanese haven't figured out yet in the several hundred years they've been at it.
He goes to the Japanese guys, explains his big idea, and asks to try it out on them. They humor him. They're polite and diplomatic about it, making him look good. So he takes that as a sign of success and goes back West to teach it as a way of learning jujitsu much faster than the normal way.
Like I said, this a reoccurring theme.
Personally, I don't see anything new in the document. And I am 100% certain the Japanese didn't learn "hara" (or shitahara or stahara) from him. They already understood it quite well, but probably didn't emphasize it when teaching foreigners for a number of reasons - mostly having to do with communication issues, but also the reluctance of the Japanese to teach foreigners the complete art.
My thoughts anyway.
Comment: great answer.  This is kind of what I expected.  You mention "this is a reoccuring theme".  Can you give me another example of a Westerner thinking he has "re-invented" an Asian martial art?  I'd like to do further research along those lines. Thanks.
Comment: I prefer older sources, from around the time when westerners were first becoming acquainted with Asian cultures.
Comment: One thing you can do is to look at the history of American martial arts. Like American Kenpo, for example. Ed Parker reinvented everything "because Americans learn differently than the Japanese do." Same with Stephen Hayes (ninjutsu). It's actually pretty common to see Americans coming up with their own brand of martial art. They have all kinds of ways of seeing things which they say separates their art from traditional Asian ones. In the 80's, this was so common that I could barely kick a rock down the street without it hitting one of these places. Hehe.
Comment: Maybe you could post this as a question, by the way.
Comment: I think it would make a good question, but I don't know how to phrase it in such a way as to promote answers that I could actually accept.  "Who are some guys who 're-invented' Asian martial arts?"  Every other answer would be Ed Parker or Bruce Lee.
Comment: It is an interesting subject, though hard to describe. Yep. One common characteristic I see with a lot of these people is that they often haven't gotten very far into a particular martial art before they decide to break off and start their own. They come up with some unusual idea and think it's "everything". And they can be highly respected people, also. Like General Choi (founder of Taekwondo). He now emphasizes the "sine wave" rising and falling motion in forms. But the Japanese forms he learned never had that motion. And it's not clear (to me at least) that it's actually beneficial.

Stahara word usage


UpdateProgress Control Remains Visible on Safari and Chrome

Question: I am using the ASP.NET Ajax controls UpdatePanel and UpdateProgress. The idea of a the UpdateProgress control is to display a message while the page is performing a partial postback, then disappear when the postback completes. On Firefox and Internet Explorer, this happens correctly. However, on Safari and Chrome the UpdateProgress control remains visible after the postback completes. Is this a bug in the ASP.NET Ajax Framework, or is there another workaround?
Answer: Could this be it? http://blog.lavablast.com/post/2008/10/20/Gotcha-WebKit-(Safari-3-and-Google-Chrome)-Bug-with-ASPNET-AJAX.aspx
Comment: This fixed the problem. It looks like the problem was originally solved here: http://forums.asp.net/p/1252014/2392110.aspx
Answer: This could be done in other way by setting up properly ASP.NET 2.0 browser support - just by putting a per-browser config to your app. For more information see here: http://www.techrepublic.com/blog/programming-and-development/manipulating-aspnet-20-browser-support/569
For BB config is here:
http://www.blackberry.com/knowledgecenterpublic/livelink.exe/fetch/2000/348583/800878/800733/How_To_-Configure.NET_2.0_for_BlackBerry_Browser_support?nodeid=1365369&vernum=0


Ability to discharge static electricity

Question: Ever since I was a child, I have been able to "discharge" static electricity in clothing by touching it.  The static falls out immediately! As a child my mother would have me touch all the laundry fresh out of the dryer and bam! All the static would disappear!  If a friend has a clingy, static-y skirt, for example, I can grab it gently in a few places and after an unpainful little zap sound (and sometimes silently) all the static electricity is gone.  How is this possible? I have never found anyone who could answer!
Comment: Everyone can discharge static electricity by touching charged objects while grounded. Probably the only difference between you and everyone else is that you're willing to do it whereas most of us avoid it.
Comment: The static charges can only persist on really clean and dry materials. As soon as you touch the fabrics you deposit moisture and conductive oils from your skin to them. Whatever charge was on there flows trough your body (you are a very good conductor for these small amounts of electricity) and you make the fabrics conductive at the same time.
Answer: Perhaps you have naturally conductive skin - a little bit of conductivity goes a long way to discharge static. Depending on how much static is built up, you may also need to have some path to "lose" the electricity - maybe your choice of footwear? Finally - you must not hate (maybe you don't feel) the little "zap". It's not just a sound - you should actually feel it. But maybe you don't.
Answer: This also happens when your body heats up a lot. You must be having higher than normal body temperature. This causes higher conductivity causing electric charge. All our bodies create electrical energy for work and functioning of organs. Our nervous system itself also discharges electrical impulses. Due to high temperature more electricity is discharged from within the body to our our outer cells i.e. hands and legs, which gets discharged on coming in contact with a conductor. This used to happen to me as well, that's when I found this info.

Ability to discharge static electricity


Not able to see the page Create your Account

Question: Accessing the <code>../admin</code> page, it shows me the login page directly instead of create your account page. I don't have any account for Craft so I'll definitely need to create an account of mine in Craft but not able to find the Create Your Account page.
Answer: You or the person who setup your system created an user account. See step 5 in the installation documentation (http://buildwithcraft.com/docs/installing). Therefore there should be an account and you could try to reset the password.
If you have access to the DB directly you could get or set the email/username associated to that account. Another option would be to start with a fresh installation.


I can't install ruby-debug-base19 -v '0.11.25 on Windows 7

Question: I'm trying to install Rails on Windows 7.
When I install I get this error:
<code>make
generating ruby_debug-i386-mingw32.def
compiling breakpoint.c
compiling ruby_debug.c
ruby_debug.c:29:19: error: conflicting types for 'rb_iseq_compile_with_option'
C:/Ruby193/include/ruby-1.9.1/ruby-1.9.3-p194/vm_core.h:505:7: note: previous declaration of 'rb_iseq_compile_with_option' was here
ruby_debug.c: In function 'context_jump':
ruby_debug.c:2414:53: warning: comparison between signed and unsigned integer expressions
ruby_debug.c:2428:27: warning: comparison between signed and unsigned integer expressions
make: *** [ruby_debug.o] Error 1

Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/ruby-debug-base19-0.11.25 for inspection.
Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/gems/ruby-debug-base19-0.11.25/ext/ruby_debug/gem_make.out
An error occured while installing ruby-debug-base19 (0.11.25), and Bundler cannot continue.
Make sure that `gem install ruby-debug-base19 -v '0.11.25'` succeeds before bundling.
</code>
I installed ruby-debug-base19 -v '0.11.26 following "Installing ruby-debug-base19 on Windows in Ruby 1.9.3"
Comment: Have you tried installing latest (0.11.25) instead?
Comment: @LuisLavena i got the same error
Answer: Just comment it out in the gemfile
<code>#  gem 'ruby-debug19', :require => 'ruby-debug'
</code>
You can try better_errors for debugging if you like Link to better_errors


WCF for REST

Question: Is wcf a viable REST solution?  It prevents you from using some special characters like # so requesting tag/c# does not work.  is there a work around, is this by design?
Comment: Check out http://stackoverflow.com/questions/tagged/rest%20wcf
Answer: REST has nothing to do with URI naming conventions. So if you want arbitrary text in your URIs, you can at the very least just use a urlsafe base64 encoding for anything.
Answer: I think its going to be difficult to find a place for REST given how WCF was designed. Remember, one of WCF's major strengths comes indirectly from its use of SOAP.  It allows web services to be accessible on any transport, HTTP, TCP, MSMQ, etc., through simple configuration.  REST has explicit dependence on HTTP, making it transport-dependent.  So REST web services would be a little bit at odds with that transport flexibility designed into the core of WCF.
I do think that WCF needs to find a place for REST web services, as it is a form of communication. However, its going to be difficult to carve out a place in the framework that makes working with REST a "natural" process; and will that negate the work that went in to making WCF what it is today?

WCF for REST


Is there any symbolism associated with Hebrew being written right to left?

Question: I am interested to know if there is any religious meaning associated with Lashon HaKodesh being written from right to left as opposed to left to right
Comment: https://www.sefaria.org/Responsa_Chatam_Sofer%2C_Orach_Chayim.187.5?lang=bi&with=all
Comment: In general, yes. The concept of starting with the right and moving left is associated with kindness. Inversely, starting with the left and moving right is associated with the opposite of kindness. This principle pertains to G-d's name of 72 triplets among many other things.
Comment: @RabbiKaii Interesting question. I'm not sure it should be described that way. On the one hand, אתהפכה means "converted into the opposite. But if you look at sources discussing this, midrash and Chassidut, it seems focused on  only the Gevurah, the left, being effected. Even though it remains distinct as Gevurah, it expresses & is perceived as Chesed. Consider the text of Kiddush HaLevanah & how the words are read right to left and then left to right. This is also related to רצו ושוב.
Comment: @YaacovDeane do you think we will switch direction after Moshiach when we switch to Beit Shammai?
Comment: @YaacovDeane `opposite of kindness` Not really an accurate depiction of Chesed/Gevurah....
Comment: @Yehuda You are entitled to your opinion but it is misinformed. Consider for example, the name of 72 triplets that we learn from Moshe Rabbeinu. The 2 polar extreme opposites are Chesed and Gevurah. The middle path between the two poles, הממוצע המחבר ביניכם, the connecting link between them is Tiferet תפארת, Beauty, which reveals G-d's Crown of Kingship פאר תורה ופאר תפלה, the Crown of Torah and the Crown of Prayer. Note that these Crowns are revealed and manifest through humility and modesty . אפר היינו עניונות.
Comment: @Yehuda In case you missed it. חסד היינו גי׳ ע״ב. גבורה היינו גי׳ רט״ז שהוא ג׳ פעמים ע״ב. That Chesed is the path of the right מפי החסד, while Gevurah is the path of the left מפי הגבורה. Please note that Moshe Rabbeinu received the Torah מפי הגבורה.
Comment: @Yehuda …And these three paths are what we learn from the Haggadah of Pesach in regard to the questions of the four sons, specifically the question from the Wise Son. His question is directed at the three general categories of Torah laws, חוק, that is above intellect, simply the command of the King, עדות, Commemorative Laws, which can be comprehended, and משפטים, which are in the domain of everyone via intellect.
Answer: In The Great Partnership Rabbi Sacks gives a speculative explanation of the difference between right-left and left-right alphabets. The book is an attempt at describing the differences between science and religion generally, which he essentially divides into two distinct categories but which can be integrated together; hence "great partnership".
Sacks says that the left side of the brain is responsible to break information down into its constituent parts and see how they interact ('left brain thinking'). In contrast, the right side of the brain is responsible for joining events together so that they tell a story and are relevant for creativity and relationships ('right brain thinking'). The left-brain is responsible for analytical processes (writing, comprehension, computation) whereas the right brain is responsible for intuition and creativity.
Rabbi Sacks says that good examples of left- and right-brain thinking is science and religion. The mantra that he states throughout is:

"Science takes things apart to see how they work, religion puts things together to see what they mean".

Rabbi Sacks uses this thematic idea to contrast "Jerusalem" with "Athens". He notes that although the alphabets are similar (aleph, bet, gimmel versus, alpha, beta, gamma):

"...in the move to Greece the alphabet acquired letters to signal vowel sounds as well as consonants... Then, between the eighth and sixth centuries BCE, it evolved into a strange form of continuous writing, beginning from right to left, then, on reaching the end of the line, turning round and coming back, left to right, and so on. Eventually, in the fifth century, it settled into the new mode, left to right, where it has stayed ever since."

Greek philosophy (Socrates, Plato, Aristotle, etc.) "emphasised the universal over the particular, the timeless over the time-bound, the abstract over the concrete particular and the impersonal as opposed to the personal". He then goes on to state this as a basis for the fundamental differences in the philosophy of Jerusalem and Athens. The Torah tells a narrative story ("right brain"), whereas Greek philosophy tells of abstract universalism ("left brain").
Sacks speculates:

"Could it be that this difference between the two cultures has something to do with the way their respective alphabets are written? Greece, at the time the alphabet was changing from right-left to left-right, became the world's first, and greatest, left-brain civilisation. It was not only a left-brain culture. There was greatness too, in the more right-brain fields of art, architecture and drama. But the conceptualisation and abstraction, the analysis of matter into its atomic parts, the Platonic devaluation of the personal and particular: all this comes with the unmistakable signature of the left hemisphere. The fact that this was hapenning at the same time, in the same place, as the emergence of the wrodls' first fully vowelled, left-right alphabet cannot be merely coincidental. The way we record and transmit information has a huge impact on cognitive styles.

The Torah narrative is in tune with right-brain thinking. Furthermore, the lack of vowels in hebrew also gives the Torah an inherent "interpretive" element to it. The Greeks used the letters to sound exactly as they are written.
I will note that this is all speculation since it is not possible to know what the reasons are for the Greeks changing the direction of writing or why Hebrew specifically started as right-left. Ancient Egypt, for example, had both left-right and right-left and even vertical writing. There are pragmatic reasons for making the switch to left-right writing, for example, most people being right-handed, causing ink to smear less when written from left to right.
Comment: It is indeed speculation. The common equipment of a scribe from Egypt from about the time of Moses would have been more convenient for right-left, just as a quill is more convenient for left-right, and this was considered answer enough to not look for symbolism for some time; however this too is reading into it a bit.
Answer: The chasam sofer answers this question in his shu"t on OC 187.
(You have to read the whole piece in order to understand the linked paragraph, so I'm not going to quote it).
The gist of it though is that there's a gemara in Yuma 59a which discusses how the kohen should sprinkle the blood on the mizbeach. Either he has walk around the mizbeach to the right and go to each of the four corners. Or the opinion holds that the mizbeach was small enough to just stand at one corner and throw the blood to each corner while standing stationary.
From this gemara we learn that "every turn one makes should be to the right." Therefore hebrew is written starting at the right side of the page and since we have to end off on the right side (as per the gemara in yuma), the end of a sefer has words written on the right side of the column leaving the left side empty.
According to the other opinion in the gemara where one is stationary, the letters themselves are written from left to right. E.g. a "ר" is written starting from the top left and ends at the bottom right.
(Let me know if my explanation is comprehensible. I'm not sure if I explained it well enough.)


How to remove title 'Navigation' from Navigation menu in Drupal 7?

Question: How to remove title 'Navigation' from Navigation menu in the left column?
Answer: You can click "edit block" or go to the Blocks administration page and enter '<none>' for block title for the Navigation block.
Answer: Drupal 8 has a check box right under Block title, allowing you deselect it and not show the block title.


Can tile be removed and placed again before it sets?

Question: 20 x 20 tiles were started today in my living room. The tile has been laid straight without any kind of staggering. They are in complete rows which is not what I had wanted. The room has not been completed yet and I am wondering if the tile can be removed at this point and done again?
Comment: Once the tile is laid, it becomes more and more difficult to remove as time passes.  It will be difficult to reuse the tile, even if it has only been down for a minute or two. You'll likely have to remove the mortar from both the tile and the substrate, and then start again. This becomes increasingly difficult (especially if you're looking to reuse the tile) as the mortar hardens.
Comment: What kind of tiles (porcelain, ceramic, stone, etc) and what substrate are they on?
Answer: I see your question was posted two days ago, so without a bunch of discussion, I think the answer at this point is a simple "no", if the tile is still on the floor.
According to the instruction sheet for VersaBond tile mortar (a product typically used to adhere tile to floors), the tile is ready for light foot traffic after 24 hours.
intructions here
In my own experience installing tile, removing a piece that has been set with mortar is the kind of thing that can be done if it's caught right away, and if it's only a piece here or there. Even if the decision to remove half a room's worth of floor tile was made immediately, say within 5 to 10 minutes of setting, doing so would take time, meanwhile the mortar would continue to harden on the the tile, including the backs of the removed tiles and the sub-floor where they were removed. Cleaning that mortar off the removed tiles and the sub-floor before it hardens to a point where it needs to be chiseled (effectively ruining the tiles, plus making a big chore out of preparing the floor again) is the main problem with removal.
It would be considered an emergency in the scope of the job. And if discovered mere hours after the fact, I would not consider it as an option but would discuss the issue in terms of "starting over" with new materials.
Good luck!
Answer: Yes but this is very very laborious.  In one of my first tile installs I messed up a back row and basically there were no backup tiles and we couldn't find the tiles locally (tiles were bought a while before).  So i have to take out and clean 20 12x12s.

to get them out alive you need to place a board on top of the first row.  Tap hammer on top of the board against the tile very very hard.  Not to the point where you are breaking the tile but a ton of effort.  You will just tap tap tap until it breaks bond with floor and pops up.  The first few tiles will be the hardest and might be a few minutes of tapping (THEY ALWAYS COME UP THIS WAY).
bucket of warm water with dish soap mixed in
bathtub of scalding hot water (pure hot water plus boil some water on the stove and add) and then add a little bleach
start tiles out in the warm bucket for 5 mins at least
put tiles in tub for 20 mins
get your stiffest putty knife, take out tiles and go at them

If the thinset isn't coming off then let set in tub longer.  It took me just a couple minutes per tile.  Good luck it is a ton of work.


Humidity levels in a basement

Question: I have a damp 28' by 60' basement with 2 concrete walls and 2 walls with paneling. What humidity level should I set my dehumidifier at?
Comment: What environment are you in? If you have cold winters, the appropriate RH varies widely by season.
Comment: I keep mine at 35%, but I also feel uncomfortable at anything above 50% in general.
Answer: I keep my dehumidifier at 60% or 65%. That's a good default when you're using the space for storage or are concerned about limiting mold/mildew.
If you're not having problems with the humidity, then consider running it at a higher setting or even removing the dehumidifier altogether. Dehumidifiers use a lot of energy.
Answer: Depends on what you use the basement for.
A setting over 75% might be okay for a storage area.  Personally, for a sleeping area, I prefer 35-45%.
While dehumidifiers use as much power as an air conditioner, once they get an area to the setpoint humidity it should not work nearly as hard afterwards to maintain the humidity—unless humidity ingresses rapidly.

Humidity levels in a basement


Computing the limit of $\lim_{t\rightarrow0}tf(g(t))$ assuming $g(0)=0$ and $g'(0)>0$

Question: Suppose $f:(0,\infty)\rightarrow\mathbb{R}$ is a continuous function and $g:\mathbb{R}\rightarrow\mathbb{R}$ is a $C^1$ function with $g(0)=0$ and $g'(0)>0$. If the limit
$$
\lim_{t\rightarrow0^+} tf(t)=a
$$
exists, can we necessarily compute the limit
$$
\lim_{t\rightarrow0^+} tf(g(t))?
$$
It seems like we can compute it as
\begin{align*}
\lim_{t\rightarrow0^+} tf(g(t)) &= \lim_{t\rightarrow0^+} tf\left(t\frac{g(t)}{t}\right) \\&= \lim_{t\rightarrow0^+} tf\left(tg'(0)\right) = \frac{1}{g'(0)}\lim_{t\rightarrow0^+}tf(t) = \frac{a}{g'(0)}
\end{align*}
but I'm not sure the step from line 1 to line 2 is valid. Is it?
Comment: You can't replace $g(t) /t$ with $g'(0)$. The right approach is the one in the answer by Fabio Lucchini. The same answer shows that continuity of $f$ is not needed and further we don't need $g\in C^{1}$. Just $g(0)=0,g'(0)>0$ is sufficient.
Answer: You get the correct value of the limit.
The same answer is obtained by:
\begin{align}
\lim_{t\to 0^+}tf(g(t))
&=\lim_{t\to 0^+}\frac{t}{g(t)}g(t)f(g(t))\\
&=\lim_{t\to 0^+}\frac 1{g(t)/t}g(t)f(g(t))\\
&=\frac{a}{g'(0)}
\end{align}
where $g(t)f(g(t))\to a$ because $g(t)\to 0^+$ as $t\to 0^+$.
Comment: +1 for your approach, but the asker's approach is not correct where $g(t) /t$ is replaced by its limit $g'(0)$.


Are stone or metal grinding wheels better for flour?

Question: I want to buy a flour mill for bread and pizza flour. I read that stone grinding wheels are better for grinding fine flour (tipo 00) than metal burrs. The mill that I am looking at does offer fine metal burrs. Any insights into which is better, stone grinding wheels or metal burrs? Can I grind "tipo 00" in one pass or do I need to do multiple grinds?
Comment: Consider an electrically powered unit. Your arm will get very tired grinding a pound of wheat into flour. I use a Victorio Hand Grain Mill which I've attached to a DC motor drive. With the proper shim, this steel grinder will get down as fine as you like, but it's **not** of a size to make grinding a pound of anything very practical.
Comment: Are you using hard or soft grain wheat? Hard grain (as in /semola do grano duro rimacinata/) will probably wear off metal burrs faster, and stone ones are probably better suited.
Comment: I am planning on using hard white spring Nebraska wheat but as this is a new adventure, I am open to new ideas. I doubt I'll be grinding enough that wearing out the burrs will be a problem. I'll be dead by then. I saw the KoMo electrics but they look boutiquey to me. Nobody appreciates a well made and beautiful wood product more than me but I am looking for a serious machine. I am leaning towards the Diamant hand driven mill right now...unless I find something better.
Comment: Diamant, good, that's set up for easy attachment of a belt drive. You *will* be tired after you've turned that handle manually 20,000 times.
Answer: Though I've never ground wheat, I've used metal and ceramic mills to grind spices, rice, and nuts. As far as I know you'll usually find either ceramic or steel burrs. Steel burrs though usually stainless steel, can still corrode depending on the type of steel used. Where as you typically want a harder steel for mills, you also want something corrosive resistant, but often a compromise needs to be made between one of the other.
Its known that ceramic burrs do a better jobs grinding to a consistently small grind. However I've never had an issue with a steel burr, though I've never ground anything to the fineness of OO flour.
As far as I've heard you should not grind anything in more than 1 pass. Its my understanding that its harder to grind something that's already been ground than it is to originally grind it to that same coarseness on the first run. My coffee grinder, which is a conical burr grinder, actually voids the manufacturer warranty if you do this. I assume this is because the burr can become clogged, and can wear out the motor.
In my experience I've preferred ceramic burrs for their ease of cleaning, they don't have issues with static like steel does so the burr rarely needs to be dusted off because it doesn't accumulate build up nearly as quickly.
As far as grinding to a finer coarseness I have no reason to believe that one is better than the other, and cannot think of a reason why that would be so. I've heard that ceramic is better for this, but cannot back that with any facts.
For other reasons I prefer ceramic for just about any type of burr. As far as fineness I've found that the size and quality of the burr can effect consistency the most regardless of the material its made out of.
Addition:
I've used this grinder for over 2 years now. I don't know if it will grind to the fineness of 00 flour, but its rather cheap and good quality.
Comment: Nor grinding in more than one single pass is probably more concerning to coffee grains/mills than what ones. Notice that "rimacinata" means "re-milled" as hard wheat grades need to be miles twice to archieve 00 finesse.


Android: Losing GPS signal strength on some phones when I start up the Camera and SurfaceView

Question: I am working on an app that takes GPS encoded pictures.
I am able to get about 15 - 20 meters accuracy GPS signal strength when I am not running the camera, and have at least 3 satellites in range, sometimes 5 - 7 satellites.
However, when I start up an activity that both displays the SurfaceView with the Camera hooked up to it AND the GPS code, my accuracy goes way down (> 100 meters), but only on some phones.
Phones that it does not work on:

Droid Incredible 2
HTC Wildfire
HTC Inspire

Phones that it does work on:

Atrix
Galaxy Tab
Motorolla Droid (The original)

So, my questions are, why would this happen?  And of course, how can I fix it?
Here is my code that I am using to stoke up the GPS
try{
    locator = new GeoLocator(this);
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    locationManager.addGpsStatusListener(new GPSStatusManager(locationManager));
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setPowerRequirement(Criteria.NO_REQUIREMENT);
    bestProvider = locationManager.getBestProvider(criteria, true);
    Bundle bundle = new Bundle();
    //I copied the next two lines out of some tutorial hoping that they would help boost my gps, but I'm really not sure what they do
    boolean xtraInjection=locationManager.sendExtraCommand(LocationManager.GPS_PROVIDER,
                                          "force_xtra_injection",bundle);
    boolean timeInjection=locationManager.sendExtraCommand(LocationManager.GPS_PROVIDER,
                                          "force_time_injection",bundle);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0.0f, locator);
}catch(Exception e){}

Answer: Complete guess here, but try changing this line:
criteria.setPowerRequirement(Criteria.NO_REQUIREMENT);

to this:
criteria.setPowerRequirement(Criteria.POWER_HIGH);

Theory: by not specifying high power requirement for the GPS, you're allowing the OS to run the GPS in a less-power-consumptive mode, which it does whenever you turn on other power-consuming accessories. When the GPS is run in low-power mode, that will make it less accurate.
Answer: Same here with a galaxy Gio GTS5660 (Android 2.3.6) and a LG5 E610.
It is actually an instance of this bug, which looks most likely to be a hardware issue: http://code.google.com/p/android/issues/detail?id=20098