Why is the assumption of free will important to physics

Question: I have watched a few lectures and have heard in quite some places that free will is an important assumption in physics. For example Bell's theorem assumes that the two experimenters can freely choose in what direction they measure the spin of the entangled particles.
But otherwise, why is free will important? Does it have to do with the fact that experimenters should be able to repeat an experiment?
Comment: Free will is maybe a too strong and ill-defined assumption. I think that you are talking about the assumption of no super-determinism.
Comment: It's an extreme misnomer.
Comment: @HicHaecHoc I just checked the definition of super-determinism. Yes, I guess I was talking about that.
Comment: I'd be rather surprised if physics were even able to formally *define* free will, let alone say whether or not it exists.
Comment: @PM2Ring Yes I think you are right. The existence Free will would probably be impossible to prove or disprove, nevertheless as far as I know it is a very common assumption and my question was, what is the reason for assuming it?
Answer: Free will is a concept that probably cannot even be defined within the scope of physics. The somewhat related concept that is usually assumed in physics is the absence of superdeterminism.

WHAT IS SUPERDETERMINISM AND HOW IS IT DIFFERENT FROM DETERMINISM
Since all of the universe had its origin in a singularity at the Big Bang, all the events in the universe descend from a common cause. Therefore, it is not unconceivable that all the events in the universe may be causally correlated. The claim of superdeterminism is that you can never assume that two events are independent.
Keep in mind that superdeterminism is not the same thing as determinism. Strictly speaking, in a deterministic universe two separate systems that have the same origin in the far past are always causally correlated, but this correlation could become undetectable, and thus practically insignificant, if the two systems evolve separately without interacting for a time long enough.
For example, think about a hammer and a bell. If you hit the bell with the hammer (not too strongly so that no permanent deformation is produced), both the objects will start to vibrate. The vibrations in the two objects are strongly correlated because they have the same origin in the collision between hammer and bell. However, within seconds or at most minutes, the vibrations will dissipate into thermal noise and no correlation between the hammer and the bell will be measurable: someone that was not present while the hammer and the bell were vibrating, looking at them will not be able to tell if in the past the hammer hit the bell or not. This can be the case even if the vibrations in the two objects are considered to be fully deterministic: in this case the correlation would still be present, but since it would be "diluted" in the thermal noise, it would be practically not measurable and thus could be completely ignored.
The claim of superdeterminism is that two separated systems can never be considered uncorrelated, not even from the practical point of view. In a superdeterministic universe, correlations may become very difficult or even impossible to measure, but, from time to time, they can always re-emerge and have significant impact on the macroscopic time evolution  of the two systems.

WHY DO PHYSICISTS USUALLY ASSUME THAT OUR UNIVERSE IS NOT SUPERDETERMINISTIC?
If our universe was superdeterministic, the scientific method, on which all of physics as a science is based, would be highly problematic. Now I explain why.
When you prepare an experiment, you assume you can control, or at least know, everything important in the physical phenomenon you want to probe. You need this, because when you don't know everything important, you cannot correctly interpret the results of the experiment. Since human experimenters obviously cannot control everything in the universe, they have to assume that most of the things they are overlooking are unimportant. That is, their correlations with the experiment are negligible.
Needless to say, if our universe was superdeterministic, this assumption would be always wrong, casting doubts on the whole corpus of science. Crazy things could happen. For example, there could exist a physical property $X$ that sometimes assumes the value $A$ and sometimes the value $B$. But the correlations that were set at the beginning of the universe were such that every time an experiment is performed, $X$ is $A$. This way experimenters would assume by scientific method that $X=A$ always, not knowing that when they are not looking sometimes $X=B$.
If the universe is not superdeterministic, we can trust the experimental method. If it is, on the contrary, we can never be sure that our experiments are not affected by some kind of "universal conspiracy", written in the correlations that were set at the beginning of the universe.
Comment: thanks that is a really good answer


Xbox360 to Dell All-in-one through HDMI cable, no sound

Question: When I connect my XBox 360 to my Dell All-in-One desktop through HDMI hook-up and switch to the HDMI source on my monitor, I get picture with no sound. How can I get sound?
Answer:
First, you need to check if your monitor supports sound over HDMI(Not all support it believe me)
Second, check if your Xbox audio settings are in the stereo mode
Third, check your volume.
Answer: The key-phrase is this:

Dell All-in-One desktop

This monitor is not even a monitor.  It is a PC attached to a monitor.
The speakers may not be part of the monitor.  It may be PC speakers that happen to be mounted to the side of the monitor, but hooked up to the PC.
You'll have to look at the specification of your device and see whether it really supports audio via HDMI.
Answer: Try the following:
1.Make sure the sound isn't muted and the volume is turned up on your TV.
2.Make sure the console audio settings are correct for your combination of TV and cables.
3.Update your console software.


Making buckwheat crepes buckwheatier

Question: I want to make "real" crêpes au sarrasin. I tried twice, but the result does not have as strong buckwheat taste as the ones I tasted in France. I am at loss since it appears impossible to increase the concentration of the buckwheat flour any further. Namely, at the latest attempt I used buckwheat flour (260g), a bit of salt, two eggs, and enough water to make the batter sufficiently liquid for the resulting crepes to be reasonably thin. The previous attempt was similar, but with milk in place of the water.
Answer: You may need fresher buckwheat flour.
Also, If you have access to a grain mill, you could buy buckwheat groats, lightly toast them, and then mill them to make your own flour.   The toasting process would amplify the flavors, just as it does when toasting nuts or spices.
Comment: Thanks for the suggestions! The flour I used this time had "best before" of Sept 2012. I do not think I can get any fresher buckwheat flour where I live. I have no access to grain mill, but maybe in the future.
Comment: I think the toasting suggestion is good - I would try it with your current buckwheat flour too, toast it a bit in the oven while it is dry. Take care not to overbake it, or its binding power will be reduced.

Making buckwheat crepes buckwheatier


Can you save your session in Julia

Question: Im very new to Julia and was trying to save my session (all the values, including functions for example) and didnt see any easy way. There seems to be a pretty complete low level write function for ints, floats, arrays, etc.  But it doesnt, for example, write a DataFrames. Is there an easy way to do this or do I need to code all this from scratch?  Im using V0.2.1.
Answer: Have you tried using the iJulia notebook?  This might be useful for what you're describing.  https://github.com/JuliaLang/IJulia.jl
Answer: You can do this with HDF5.jl. I don't know how well it works for functions, but it should work fine for data frames and any other native Julia type.
For functions you want to keep, I would probably just define them in a regular .jl file and include("def.jl") at the start of the session, for example.
Answer: Checkout out the Julia Data Format https://github.com/JuliaIO/JLD.jl
It can both save specific julia types as well as types you created yourself, and has macros to save your entire workspace at once.
Comment: Could you please add few points, because it looks  more like a comment than an answer.
Answer: I think it can be in Julia Data format (JLD).
https://github.com/JuliaIO/JLD.jl
If you have own data fromat e.g. type model
type Model
  version::String
  id::String
  equations::Vector{Equation}
  coefs::Vector{Matrix}
end

You can save it with command
using JLD
save("MODEL.jld", "modelS", model1)

and read as
pathReport = joinpath(homedir(),".julia/v0.5/foo/test")
m = JLD.load(joinpath(pathReport, "MODEL.jld"))
model2 = m["modelS"]
model2.equations[1].terms[2] == "EX_01"

Can you save your session in Julia


Marrying non EU citizen

Question: I am a EU citizen. I'm currently living in london  and I'm looking to marry my partner  who's a non EU citizen and he's living in the UK with his parents and my partner is dependent  on his moms visa. But at the same time their visa is on pending.   Since I am an EU citizen  is there anyway that if I marry him he will be able to stay with me or either apply for  EU passport.
Answer: He probably won't be able to apply for an EU passport, but that will depend on your country of citizenship.  Italy, for example, has an accelerated naturalization procedure for spouses of Italian citizens.
He will, however, be eligible to stay with you in the UK under the EU freedom of movement regime if you are married before the UK leaves the EU, and probably also under the new system that will replace it if you marry afterward.  See Settled and pre-settled status for EU citizens and their families for more information.

Marrying non EU citizen


Optimizing jQuery dynamic adding of inset border effect

Question: I'm not that experienced with jquery and javascript but I managed to get this code working for my Drupal website (I've included the beginning and end of the required Drupal jQuery calling code for reference, as the 'context' part makes it work with Ajax refreshing there so as a reference of sorts, feel free to ignore)
<code>(function ($) {
Drupal.behaviors.borderfarba = {
    attach: function (context, settings) {

        var nmbr = 1; /// this will be a counter
        var backcolor; /// here I store the generated random color
        $(".movierow", context).each(function () {

            /// I declare a class + a number from the counter
            var clrclass = "clr" + nmbr;

            /// I add this class to each .movierow class
            /// which is inside a div containing divs with the other classes
            $(this).addClass(clrclass);

            /// storing the random color
            backcolor = get_random_color();

            /// pass the  class and color value to function
            addborder(clrclass, backcolor);

            /// up the counter
            nmbr++;
        });

        function addborder(clrclass, backcolor) {
            /// before the inset border effect I also
            /// apply the backcolor to a title and rating field
            /// that appear over the image

            $("." + clrclass + " .views-field-field-screenrate").css("background", backcolor);
            $("." + clrclass + " .screentitle").css("background", backcolor);

            /// apply the inset border effect
            $("." + clrclass + " img").insetBorder({
                borderColor: backcolor,
                inset: 5
            });
        }

        /// randomization functions
        function rand(min, max) {
            return parseInt(Math.random() * (max - min + 1), 10) + min;
        }

        function get_random_color() {
            var h = rand(40, 130);
            var s = rand(30, 75);
            var l = rand(40, 60);
            return 'hsl(' + h + ',' + s + '%,' + l + '%)';
        }

        /// add a nice slide down/up effect
        /// on mouse in/out for the title
        $(".movierow").hover(
        function () { $(this).children(".screentitle").slideDown(); },
        function () { $(this).children(".screentitle").slideUp(); }
        );

    }
};

})(jQuery);
</code>
The point is I want a  new random color within a specified range (like in my case from reddish hues to green) applied to the jQuery inset border effect found here which is then applied to each image on my page (which are generated dynamically). PS. I think I found the random color generation code snippet somewhere around here, so thanks to that one person, don't want credit where it's not due.
Thus I used a loop which adds a new class to each image and then applies the inset border function to each class.
I'm wondering if there's any way of optimizing this code to be more efficient, as this is the only way I figured how to do it.
Cheers and thanks for any advice, hoping to improve my under par programming skills
UPDATE I have modified the code a bit (and added comments), as I needed the same random background color for 2 additional fields that appear over the image (title, rating)
Answer: Not an answer, but a question...
Why do you convert 'nmbr' to a string?
<code>  /// I declare a class + a number from the counter
  var clrclass = "clr" + nmbr.toString();
  /// I add this class to each .movierow class
  /// which is inside a div containing divs with the other classes
  $(this).addClass(clrclass);
</code>
Wouldn't this be simpler?...
<code>   $(this).addClass('clr'+nmbr);
</code>
Otherwise, your code looks very performant to me, but I'm far from an expert.
Comment: Indeed you're right, I don't need to convert, thanks. Added that automatically, bad habit from switching between languages.                   But I think I still need to keep it in the variable, as I'm passing it around other functions.


Replacing Grout Around Kitchen Sink

Question: first time poster, hope someone can help.  The grout around my kitchen sink is old and broken, and I'd like to replace it.  Not sure if it would be better with grout or caulk (I've never used grout, but I have some experience applying silicone caulk).  I live in a rental, so I don't want to go crazy, but it's worth a couple bucks and a few hours of my time to make it look better.  Any advice on the best material to use, any tools I might need or good videos / guides would be greatly appreciated!
Answer: Hard to tell if the material between the tile and sink is cement or backing board.  Anyway,

If that corner tile or any other one is loose and can be removed without breaking it, do so.
Use a dremel to remove exposed tile cement from removed tiles and all  the visible edge cement, to about a quarter inch deep.  You're creating a gap that you will replace with new material.
Also with a dremel remove the grout lines between the edge tiles.  Looks like the ones between the edge and regular tiles are ok.  Look at youtube tutorials on how to do this.
Use tile cement to replace tiles that were removed.  Force a little construction adhesive into the gap you made at the edge of the sound tiles.
Regrout the lines between the tiles.  NOT the sink edge.
Use silicone caulk at the interface between the tiles and sink.
Comment: Yeah, you should use caulk between the edge tiles and the sink, instead of grout.

Replacing Grout Around Kitchen Sink


Copy iTunes playlists to external USB flash drive

Question: I have lots of playlists on my iTunes library, and I want to be able to copy the music of certain playlists to a flash drive to play on a stereo system. I have too many songs in too many folders to just copy the raw .mp3 files, so that option is out. Any other ideas?
Answer: Unless I miss something, you can just drag & drop the playlist to your USB drive.
Comment: I don't know why, but I couldn't the first time. I decided to try again, and it just started copying :S I have no idea what changed
Answer: iTunesExport is a Java program that you can use to export iTunes playlists including the music files to a specific directory or drive.
If you regularly want to export iTunes playlists the iTunesExport command line version makes it easy to create bash scripts you can reuse.


What is saved in wallet.dat exactly?

Question: As I know, wallet.dat saves all related data for a bitcoin wallet.  However, I don't understand what precisely is saved in the wallet.dat.  I think it must contain several private keys. Does it also contain the corresponding public key, and seed value?  Anything else?
Answer: The wallet.dat file contains your private keys, public keys, scripts (which correspond to addresses), key metadata (e.g. labels), and the transactions related to your wallet. If you have an HD wallet, it also includes the HD seed and and the derivation paths for each private key.
Comment: So 'backup wallet' is actually mean 'backup wallet.dat' and 'restore in another wallet support wallet.dat format', for all circumstances. Is this correct?
Comment: Yes, that is correct.

What is saved in wallet.dat exactly?


php: command not found on centos

Question: I've currently installed CentOS (6.5 version), nginx, mysql and php. I've tried to navigate to  index.php in a browser, and it looks fine, but if I try to run the script via the command-line I get:

php: command not found

Why did that happen? How can I solve it?

Edit: I tried to install the php-cli package:
# yum install php-cli
Error: Package: php-cli-5.3.3-40.el6_6.x86_64 (updates)Requires: php-common(x86-64) = 5.3.3-40.el6_6
           Installed: php-common-5.4.35-1.el6.remi.x86_64 (@remi)
               php-common(x86-64) = 5.4.35-1.el6.remi
           Available: php-common-5.3.3-38.el6.x86_64 (base)
               php-common(x86-64) = 5.3.3-38.el6
           Available: php-common-5.3.3-40.el6_6.x86_64 (updates)
               php-common(x86-64) = 5.3.3-40.el6_6
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Answer: You have to install the commandline interface version of php before you can use it from bash:
yum install php-cli

the commandline version is not necessary if PHP is part of a page in nginx.
Comment: See edited post

php: command not found on centos


Running classic ASP on ASP.net page

Question: I have a classic ASP forum, I'd like to use a master page and contain the forum inside it.  Is this possible without frames?
Answer: There are two strategies you could use to avoid frames.
Ajax.
There are two ways you could use ajax to do this.  One would be to use ajax to get forum contents to populate master page.  The other would be to put the ajax call to generate the page template "wrapper" in the classic asp forum code to call you asp.net app to generate the page template.  Essentially both are putting the pieces together on the client side.
Proxy method.
Similar strategy but doing the putting together on the server side...
Utilize your aspx pages to make a call (webrequest) to your classic asp page, essentially proxying the call to the actual asp page and then consume the returned HTML on the server side and render it utilizing the master page.
Neither are great solutions... the ajax method I would argue against and just use an iframre.  The proxy method is a bit more complicated but would get rid of the frame.
Answer: You could perhaps use an inline frame (iframe) to hold your forum.  You'll still need a dedicated content page with the html for the iframe.
Answer: Create a hidden iframe with the the forum inside of it.  Get the document element from the iframe window using javascript and put the contents of the document element inside a div on the master page.
On each event in the document element of the iframe, reload the div.

Running classic ASP on ASP.net page


iPhone text messages

Question: I do not want my new iPhone to open text messages automatically when I tap the icon because of this recent scam thing with "you've won a prize". I've gotten that message 3 times so far, and I have to wait until someone sends me another message to keep it from opening automatically.  Last night, I asked someone to send a message, they sent it, and I was able to go into text messaging & delete the "prize" message without opening it.  It popped back up within a short time, so I would like to be able to select text message without my iPhone automatically opening the message if there is only one new one.
Comment: Im not sure what the "prize" thing you mention is all about, but if it's just a text message, and not an email, then there should be no problem with just reading and deleting it, there is nothing it can do just by being viewed.
Answer: I had a google, and found this for background reading.
Unlike email, which has the potential to be abused without your consent merely by opening a message, there is no risk attached to simply viewing such messages provided they are received over the SMS network.  They may contain links that you do not want to visit, but they cannot visit those links for you without your direct consent (and indeed action to click it).  So if you receive such messages, simply delete them.  For peace of mind, don't delete the message directly (there is a small change a swipe could go wrong and leave you clicking the link by accident) just drop back to the recipient list, and delete the conversation.
Comment: Thank you so much.  I didn't know if there might be a problem just by opening it.  Appreciate your assistance.
Answer: If you hit the lock button twice, the slider on the unlock screen won't go directly to the app.
Answer: I'm afraid I have to disagree. Here in Argentina those "scam" SMS are risky. The simple act of opening one of those messages allows the company to charge you a monthly fee just for receiving more SMS (scams) daily. I know it's an abuse from the phone company allowing this, but it's happening here. Consumers are not protected in Argentina, that's why they worked around this Iphone flaw.
Comment: I don't think this is correct; there is no technical way, simply by reading the SMS, that anyone can be notified you have read it. Is there any concrete evidence that this has happened?

iPhone text messages


MacBook Air and LCD Projector

Question: When Presenting a powerpoint I tried to minimize the PP and go online to demo. The site comes up on my Laptop but not on the projection. That only displays the home screen.
Answer: You can drag the title bar of the browser window over to the other display. If you open the System Preferences > Displays, then Arrangement tab, you can see where the projector's display is in relation to the laptop display. The main display (typically the laptop's) has a tiny white menu bar depicted in this Arrangement window.
Just click-drag the window in the direction of the second display and it will pop over to the projector.
You can also change the arrangement if it helps. Put the projector above, below, left/right of your laptop display.

MacBook Air and LCD Projector


How long does it take to travel by road from Buenos Aires to Rio De Janeiro?

Question: if any of you people know how long does it take to travel by road (bus/car) from Buenos Aires to Rio De Janeiro, please tell me. I love travelling on land, and am planning to visit South America Next Month.
Answer: It takes about 40 hours by bus.
that's according to the schedule of omnilneas
I would recommend to break the journey into several pieces, there are lots of things to see on the way.


Override the Cartthrob license key generation process

Question: Is there a way to override the Cartthrob license key generation process?  Currently Cartthrob just defaults to a UUID, but we have a more in-depth license generation process that is required for our project.  I can probably hook into cartthrob_on_authorize, but am wondering if there is a better way.
Answer: No I think creating your extension and hooking that event is the right way forward. This sort of thing is why they put hooks in there after all, do you think that hook will be too late, i.e. after UUID generation?
Answer: There is no way to override the built-in key generation. I would recommend turning it off in the settings (by leaving the License Number field mapping empty in the Purchased Items channel). And then using the cartthrob_on_authorize hook.
foreach (ee()->cartthrob->cart->order('purchased_items') as $entry_id) {
    // generate your own license key
    //$key = ?

    // save the key to the DB, where XXX is your Purchased Items' license number field ID
    ee()->db->update('channel_data', array('field_id_XXX' => $key), array('entry_id' => $entry_id));
}

Comment: Thanks Rob, much appreciated.  This is the route I ended up taking.


Tumblr imported blog showing wrong date

Question: I imported my Tumblr blog to Wp but all my blog are showing the preceding date as the date of publishing. I even changed the timezone of my wp account to my location before importing but the problem persists.
Comment: Does dates match in the Tumblr export file?
Answer: Option 1 (no code): you can manually edit each post and change the published date. Look in the "Publish" box where you publish or update posts, and there will be a "published on" date with an "edit" link.
Option 2 (requires database access): you can run a MySQL query to adjust all posts' dates.
UPDATE wp_posts SET post_date = DATE_ADD(post_date,INTERVAL 1 DAY) WHERE post_type = 'post';
UPDATE wp_posts SET post_date_gmt = DATE_ADD(post_date_gmt,INTERVAL 1 DAY) WHERE post_type = 'post';

There are two lines because WP stores both a local timezone timestamp and a GMT timestamp.
This assumes your database uses the default wp_ prefix - you should first back up your database, then check which prefix you use, and if it's a different prefix then just update wp_posts in both lines to whatever yours is called.

Tumblr imported blog showing wrong date


Windows 11 Pro not booting when installed onto a USB via WoR:

Question: I recently created a Windows 11 Pro ARM64 .iso through uupdump.net aria2c to .iso conversion everything went fine the .iso was made i then launched WoR (Windows on Raspberry) everything was done correctly i used the default option apart that i selected wimlib as the install and choose to use lzx compression, my Raspberry Pi is the 4B model the eeprom was updated to usb-boot, it is the model with 4Gb of ram, i am also using a 64Gb Kingston 3.0 usb, once it installed correctly i ejected the usb from my pc, Then i plugged into the Rapberry Pi, plugged in ethernet, plugged in my keyboard, connected it to my monitor and then plugged it into the power outlet, it booted up fine via the usb 3.0 port, i ajusted the setting, display: 720p, ram: use all ram. saved, exited BIOS, pressed enter to boot, then it just kept on the boot screen for 10 mins, then it started verbosing, it just said two lines: no internet connection detected, no internet connection detected, and stayed like that on the boot screen. Am i missing any steps on how to do this? Or is this a common issue?
Edit: I tried rebooting several times, after two reboots it finally just gave the rainbow screen.
Answer: Booting Windows on Raspberry Pi is not fast enough compared to PCs, but some options can help you anyway:

Use fast 100 MB/s U3 Class 10 SD card (like SiliconPower Superior Pro)
Change the boot order in the boot option to disable the UEFI ethernet check.
Be a little bit patient :)

And for better performance:

Disable transparent effect in windows.

Change the performance option : Right-click on This PC > Properties > Advanced system setting > Performance > setting > Adjudt for best performance

Install IoT Enterprise version that is lighter than the Pro version.
Comment: The OP actually says **"not booting"** in the titlle and "kept on the boot screen for **10 mins**".   10 as in minutes. Are you saying that the solution is simply to "Be a little bit patient"?!?   What would be too long -- a few hours?  Two weeks?
Comment: @goldilocks I just said it's not fast compared to PCs :)  When I tried to boot windows on RPi using the U1-SD card I waited almost 10 minutes, but with the U3-SD card, it was 2 min. Flashing windows on U1 was 5 hours but in U3 was 18 minutes. Booting on U1 was 10 or 15 min but on U3 was 2 or 3 minutes. U3 is so good :)


SVG not rendering in Safari

Question: I have several pages on my site that show SVG images on any browser without a problem.  One of the pages shows two different SVG images, and one of them is a pretty complex image.  In my Chrome Web Browser, the complex image shows up without a problem, but when I try to view that page in Safari the SVG shows up with blank spots in the image where there is supposed to be content.
I think I need to replace the image with a PNG version of the SVG image for Safari browswers, but I have no idea how to do that.  Does anyone know how I can fix this SVG problem or replace the SVG with a PNG if the web client is safari?
Answer: If you are trying to do an inline SVG I dont think it's supported in Safari:
<!DOCTYPE html>

        <meta charset="utf-8" />

        <svg id="newYear" height="200" xmlns="http://www.w3.org/2000/svg">
            <circle id="year" cx="150" cy="150" r="50" fill="blue" />
        </svg>

You should try declaring it like you would an image:
<!DOCTYPE html>

        <meta charset="utf-8" />

        <embed src="circle.svg" type="image/svg+xml"></embed>
        <object data="circle.svg" type="image/svg+xml"></object>

I would also look into a PNG fallback.  A Google search will render results on how to do a fallback for legacy browsers.  Have you looked into previous question?

Not able to render SVG image in Safari
Safari embeded SVG doctype

If you want a better answer I would suggest editing your question to show what you've tried and the code because it's hard to ask for help when we have no clue what the you're doing exactly.

SVG not rendering in Safari


Families of ideals with a given initial ideal

Question: Assume a fintie set of monomials is given. Is there a way to find the family of ideals whose initial ideal (say w.r.t revlex order) is generated by that finite set? I'll appreciate any partial answer, reference or suggestions.
Answer: It's kinda gross, but it can be done.
To each monomial, add a generic linear combination of all smaller monomials (w.r.t. your term order).
Now insist that what you have is a Gr\"obner basis. How do you do this? Apply the reduction algorithm to each S-polynomial, until you get stuck. Then assert that the result is zero. This puts a multitude of algebraic conditions on the coefficients in your generic linear combinations.
I hope it's obvious that the resulting set thus constructed, a Bia\l ynicki-Birula stratum on the Hilbert scheme, should be termed the "Gr\"obner basin".
Comment: Sorry, all I mean is that you should put in a coefficient for _every_ possible term, then use the above to constrain the coefficients. This answer makes no assumption of genericity; it really does find every  ideal with this initial ideal.
Comment: Thank you for your answer. Theoretically it is true But the problem ist I don't know how to be sure that the combination is a "generic" one in a concrete given situation. However I know that this problem should not be very easily accessible too, since the consequences are very surprising!


Windows auto-update uses external drive

Question: When using Windows auto-update, it seems to save the install files on my large external hard-drive, rather than my Windows c: drive.  I'd rather not have all that stuff on my external drive - is there any way to force it to only use c: for windows update files?
Answer: The windows update files are downloaded to your c drive, i.e. the same drive windows is installed.  They should be in %systemdrive%\windows\SoftwareDistribution
What i think you mean is that you end up with folders like:  X:\ee9bb670ca8d1b9684e57427c9bd30  on your external drive?
From what i understand, the behavior of most windows security updates is to extract themselves into a randomly generated folder, on a local disk drive with the most free space.  Not sure if there's an easy way to fix this other then having more free space on your c drive then your external HDD.
Just a guess here, but if you can flag the drive as removable, maybe windows wont try to extract the files there?
Comment: That is my understanding of where the files are located and extracted too. I don't think it cares if the drive is removable as I've seen it use a large USB stick before now. I've never seen it use a network drive though, so it does have some filtering in what it consideres valid extract points.

Windows auto-update uses external drive


Words the Holy Ghost teaches with

Question: Is there a compilation of Biblical words in which the Holy Ghost teaches with?
Comment: I have edited and quoted your reference as I think you are referring to verse 13, primarily. Welcome to SE-C. Please see the Tour and Help (below, left) as to the purpose and the functioning of the site.
Comment: @ClementBaptiste Feel free to contact me through my profile wherein is  my email address. Kind Regards.
Answer: I would say, Yes, definitely.
For example the word 'redemption' has a common meaning in the English language and is used in regard to mortgages and financial transactions. It is also used in a very loose way meaning that one can 'redeem' oneself from a bad mistake by correcting that mistake.
But in scripture we see two Hebrew words in the Old Testament scripture translated 'redeem' - gaal and padah. These two words are related and have precise meanings.
Then in the New Testament Greek scripture we see two sets of words, which relate to the two Hebrew words. One set of Greek words is agorazo/exagorazo. The other set is lutron/lutrosis/apolutrosis.
I am not going to go into all this as this answer is not about 'redemption' as such : it is about how words are used.
If one studies the very logical setting out (by the Holy Spirit who inspired all of scripture) of the two Hebrew words and the two sets of Greek words, one will come to an understanding of what we call (in the English language) 'redemption'.
Strictly speaking, we need two words to describe 'redemption' since there are two Hebrew words and two sets of Greek words.
But it is, in my view, sufficient (for the time being until we can really sort this out properly) to at least be aware of what is there in scripture, so that we can be intelligent in our reading of it.
This is a word (strictly speaking - two words) which the Holy Spirit would have us to understand. I would say.

I study the KJV myself and I have found Young's Analytical Concordance an invaluable tool. All of the above (regarding the word 'redemption') is set out, very neatly and simply, in the two halves of Young's Concordance, the first half being a list of the English words used in the bible and the second half being a Hebrew/Greek lexicon (that is all written in both anglicised letters and original letters) so that one can see the different English words that a particular Hebrew/Greek word has been translated into.
Without Robert Young's extensive lifelong labours, or the equivalent, such as I would not have been able to write this answer at all.
Comment: Thanks for showing that the "spiritual" words are those of the Bible, and not some other magical or mystical language!
Comment: @curiousdannii Well, it is good to bear in mind that for every deed, every word and for every action, we will give an account thereof, at the judgment seat of Christ, in the day of the Son of man.
Comment: Thank you Nigel J for the answer and the Yong's concordance reference.
Comment: @ClementBaptiste You are most welcome. The Lord bless thee.

Words the Holy Ghost teaches with


A faulty "proof" regarding exactness of derived functors

Question: I've been trying to wrap my head around derived functors and have come upon the following chain of arguments, which seems to yield the unreasonabel conclusion that all left derived functors are exact. I presume there must be some mistake, but have thus far been unable to find it, and would be gratefull for any help. The argument goes like this.
Take some exact sequence
$$0 \rightarrow A \rightarrow X \rightarrow C \rightarrow 0 $$
With projective resolutions $$A_* \rightarrow A, C_*\rightarrow C$$
By the horseshoe lemma we may choose a projective resolution $X_*\rightarrow X$ st. $X_n = A_n \oplus C_n$, s.t the sequence of deleted deleted chain complex
$$A_*\rightarrow X_* \rightarrow C_*$$
with connecting arrows respectively the injection and projection of the coproduct, is a split short exact sequence of chain complexes. We may compute our left derived functor on our original sequence using this sequence, and since derived functors are only defined on additive functors, homology functors are also additive, and additive functors preserve split exact sequences, this seems to suggest that the derived functor on any short exact sequence yields a split short exact sequence.
A conclusion that seems mildly utopic, if any one can point out what i did wrong it would be much appreciated.
Answer: The middle complex $X_\ast$ has terms that are $A_n\oplus C_n$, but it is generally not true that $X_\ast=A_\ast\oplus C_\ast$ as complexes. To compute the left derived functors of $F$ you would apply $F$ to each of the three resolutions and take the homology. It is indeed true that you will have split exact sequences $$0\to F(A_n)\to F(A_n)\oplus F(C_n)\to F(C_n)\to 0,$$ but the differential in the middle column will not be the sum of differentials of the outer columns. As a result, you will not get a split exact sequence $$0\to H_n(F(A_\ast))\to H_n(F(A_\ast))\oplus H_n(F(C_\ast))\to H_n(F(C_\ast))\to 0.$$
To have a look at what's going on, you can try to write the three resolutions explicitly for the exact sequence $$0\to\mathbb{Z}\to\mathbb{Z}\to\mathbb{Z}/2\mathbb{Z}\to 0$$


How much input fluid is needed to fully replace the contents of my inline chamber

Question: I have built a simple inline chamber for my irrigation system. I have made it so I can add powdered fertilizer to the chamber which will then be pumped through the system to the drip feed sprinklers. What I need to know now is how many liters of water must enter the chamber to replace the original contents. The inside diameter of the chamber is 88mm and the length is 596mm. That gives me approximately 3.6 liters (ignoring the small volume for the thread cap in the center). Now both the input and output hoses are 13mm (outside diameter) which connect to two taps both are 28mm (outside diameter) as they pass through the chamber ends. You can see it below

I expect the input (on the right) to mix with the fluid in the chamber which  means I will need to push more than 3.6 liters through the system to get the bulk of the fertilizer out of the chamber. I also expect the concentration of the fertilizer to drop relatively quickly at first but slow down as the mixing process continues to dilute the mix in the chamber. What I need is a rough estimate of how many liters I need to push through the chamber to get the majority of the fertilizer through.
Comment: This is not a physics question. Please refer to [What topics can I ask about](http://physics.stackexchange.com/help/on-topic) to know more.
Comment: Is it necessary to push any water through the chamber? If the powder has dissolved, won't the action of gravity push it out without any need to be flushed?
Answer: The answer will really depend on the degree of mixing that happens. If there is "no" mixing in the chamber, then the entire volume $V$ will be replaced by pushing just $V$ additional fluid through. But the question is more interesting when you have perfect mixing - so let's set up that problem and do the math:
A chamber of volume $V$ has a certain initial concentration $C_0$ of fertilizer. We add $q$ water per unit time, and remove an equal volume of water-plus-fertilizer. What is the concentration of fertilizer $C(t)$ as a function of time?
In a short time interval $dt$ during which we assume the concentration is constant, the quantity of fertilizer removed is $C(t)~q~dt$. This means the equation for concentration with time is
$$C(t+dt) - C(t) = -\frac{C(t) q}{V} dt\\
\frac{dC}{dt} = -\frac{Cq}{V}$$
We can integrate this to get
$$C(t) = C_0 e^{-qt/V}$$
That means that every time you get a volume $V$ of liquid through your mixing chamber, the concentration drops by a factor $1/e$ or roughly 37%.
To get down to 1% of the initial concentration, you would need 4.6 V of water, since $e^{-4.6} = 0.01$
I hope you can work with this. What exactly consists of "majority of fertilizer" is of course something you need to decide for yourself. The table below may help:
<code>conc    volume
0.001   6.91 x V
0.003   5.76 x V
0.010   4.61 x V
0.032   3.45 x V
0.100   2.30 x V
0.316   1.15 x V
1.000   0.00 x V
</code>
Comment: @Floris your answer was exactly what I was after. Thank you.
Comment: You seem to be making some assumptions about the solubility of the powdered fertilizer and its concentration in the chamber.
Comment: @sammygerbil yes I assume it is perfectly dissolved. If you take that assumption away but don't provide details, there appears to be no physics question left...


Piped search queries in vim or less

Question: I would like to be able to search a log file for lines that being with ^2014-02-18 15:30:[0-9:,]* and have UserName:someguy much later in the same line.  I am sure I could do a regex to include any number of characters, digits and spaces before that point, but I would like to know if I could effectively do something like /^2014-02-18 15:30:[0-9:,]* | /UserName:someguy  meaning pipe the results of the first search through the second search, while still in vim or less.  Obviously I could do this with grep externally.
Comment: How about `grep /^2014-02-18 15:30:[0-9:,]* | /UserName:someguy | vim -`. It will open the contents in vim editor with only the lines having the above patterns in it.
Answer: :v/^2014-02-18 15:30:/d

in vi deletes all lines except those matching that pattern. Then you can filter more with:
:v/UserName:someguy/d

Though you could do it in one go with:
:v/^2014-02-18 15:30:.*UserName:someguy/d

In less, type & and then ^2014-02-18 15:30:.*UserName:someguy

Piped search queries in vim or less


Any Dua(s) To Stop Or Reduce Nocturnal Emissions

Question: Salam
I am A Teen Boy, And I Have Been Having Constant Nocturnal Emissions For The Past 2 Years (Even Sometimes Waking Up 3 Times In One Night), however, these Days because the schools are open and start earlier, i am unable to catch my Sleep plus these days i have them while i am sleeping on my stomach, which means the whole bed sheet and bed needs to be washed, and i feel bad for my Mother, Have been to several doctors but nothing seems to work, does anyone know any Dua Or Any Surah That I Should Recite Before Sleeping to Stop This, Pls Answer As Now its starting to effect my everyday life
(I Dont Watch Any NSFW Stuff, nor Do I Masturbate)
Comment: Why should somebody want something ton stop which is natural and given by Allah.
Comment: Bcoz its starting to effect my daily life....i wouldnt mind it happening 2 or 3 times a month but 5/6 a week Is just ridiculous
Answer: Listen boy!  This is a thing you and we (male men) can't control. Allah 'azzawajal created us like this way. THIS is a very common and very normal thing in male especially when they are hitting puberty. There is "NOTHING" can help us to stop having nocturnal emissions or wet dreams, really! I'm not kidding! It's our nature. Some boys have nocturnal emissions  a few times a week, some have them only a couple throughout their life!!!!
There is nothing wrong with having more wet dreams or not having nocturnal emissions at all!!!  Having nocturnal emission/wet dream is a normal part of growing up. So, you must not feel guilty or ashamed about having them a lot.
Now what Medical-science tells us about wet dream/nocturnal emission is that wet dreams/nocturnal emissions  are caused by a rise in levels of the hormone "testosterone" that happens in a guy's body during puberty. Having them is a pretty common sign of puberty. They aren't a sign of a health problem or diseases. The most important thing is that they don't cause any harm. However, they can be confusing and embarrassing at first. Don't  panic.
Now let me suggest you to do a couple of things as precaution
1/ Try sleeping with a towel nearby.
2/ If you're sleeping at a friend's house/ your relative's house, have a change of underwear with you.
3/ Avoiding sleeping on your stomach.
4/ Always urinate before sleeping.
✪5/ Avoid masturbation strictly. (In islam, masturbation is totally prohibited).
✪6/ *Avoid watching porn. (Watching porn, erotic stories, audio porn, sfw, nsfw are ➤ Prohibited in islam).
7/ Amorous thoughts and discussions must be avoided.
8/ Daily exercise should be done. This is very important. Take care of your body shape. Don't be a fat flabby guy!! Make your body strong and fit. What about having a six pack abs!!! Build your bicep like an egg. Try to do ~100 push ups daily! Invest your time on working out. You can follow these YouTube channels
☞ https://youtube.com/c/IvanRusakov
☞ https://youtube.com/c/JeremyEthier
☞ https://youtube.com/c/athleanx
https://youtube.com/channel/UC_nfjMmJlJXrhl2xbP9wwgRA
☞ https://youtube.com/user/FitnessFAQs
[Islamic prescription] must be followed in  daily basis
1/ Go to bed early. Prophet Mohammed (may peace and blessings of Allah be upon him)
disliked it to stay awake after Isha prayer without any necessity.

✔Abu Barza reported: رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ
وَسَلَّمَ كَانَ يَكْرَهُ النَّوْمَ قَبْلَ الْعِشَاءِ وَالْحَدِيثَ
بَعْدَهَا The Messenger of Allah, peace and blessings be upon him,
disliked to sleep before the evening prayer and to talk after it.
Source: Sahih Bukhari 543, Grade: Sahih
✔Aisha reported: مَا نَامَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ
وَسَلَّمَ قَبْلَ الْعِشَاءِ وَلَا سَمَرَ بَعْدَهَا The Messenger of
Allah, peace and blessings be upon him, would not sleep before the
evening prayer and he would not stay up after it. Source: Sunan Ibn
Majah 702, Grade: Sahih

2/ It is recommended to perform ablution before going to sleep.

✔Ibn Umar reported: The Messenger of Allah, peace and blessings be
upon him, said: مَنْ بَاتَ طَاهِرًا بَاتَ فِي شِعَارِهِ مَلَكٌ فَلَمْ
يَسْتَيْقِظْ إِلا قَالَ الْمَلَكُ اللَّهُمَّ اغْفِرْ لِعَبْدِكَ فُلانٍ
فَإِنَّهُ بَاتَ طَاهِرًا Whoever goes to sleep in a state of purity
will have an angel over his head and he will not awaken until the
angel says: O Allah, forgive your servant for he has slept with
ablution. Source: Sahih Ibn Hibban 1064, Grade: Sahih

3/ It is recommended to pray the voluntary witr prayer (salat al-witr) before sleep.
[If you fear that you will not get up at the end of the night you should pray Witr before you go to sleep].

✔Jabir reported: The Messenger of Allah, peace and blessings be upon
him, said, "Whoever fears he cannot stand for prayer at the end of the
night, let him perform Witr prayer in its beginning. Whoever hopes to
stand for prayer at the end of the night, let him perform Witr prayer
at its ending. Verily, prayer at the end of the night is witnessed,
and that is better." Source: Ṣaḥīḥ Muslim 755 Grade: Sahih
(authentic) according to Muslim عَنْ جَابِرٍ قَالَ قَالَ رَسُولُ
اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ خَافَ أَنْ لَا يَقُومَ
مِنْ آخِرِ اللَّيْلِ فَلْيُوتِرْ أَوَّلَهُ وَمَنْ طَمِعَ أَنْ يَقُومَ
آخِرَهُ فَلْيُوتِرْ آخِرَ اللَّيْلِ فَإِنَّ صَلَاةَ آخِرِ اللَّيْلِ
مَشْهُودَةٌ وَذَلِكَ أَفْضَلُ 755 صحيح مسلم كتاب صلاة المسافرين وقصرها
باب من خاف أن لا يقوم من آخر الليل فليوتر أوله

4/ It is recommended to perform the prophetic supplications before going to sleep.
You should learn and memorize all of these adhkar....
https://preciousgemsfromthequranandsunnah.wordpress.com/2018/11/29/authentic-adhkar-before-sleep/
and read them Daily beofore going to sleep.
5/ It is recommended to wake up early enough to perform the two voluntary cycles of prayer before congregational dawn prayer.

✔Aisha reported: The Messenger of Allah, peace and blessings be upon
him said: رَكْعَتَا الْفَجْرِ خَيْرٌ مِنْ الدُّنْيَا وَمَا فِيهَا [Two
bowings of prayer before the dawn prayer are better than the world and
whatever is in it] Source: Sahih Muslim 725, Grade: Sahih

6/ It is recommended to praise Allah, to remember the Hereafter, and to perform supplications after waking up.

✔Abu Dharr reported: When the Messenger of Allah, peace and
blessings be upon him, woke up he would say: الْحَمْدُ لِلَّهِ الَّذِي
أَحْيَانَا بَعْدَ مَا أَمَاتَنَا وَإِلَيْهِ النُّشُورُ {All praise is
due to Allah who has given us life after our death and to Him is the
resurrection} Source: Sahih Bukhari 6960, Grade: Sahih

So, dear! These are the things that might help you Insh-Allah. And Don't forget to make a lot of dua in your sujood(prostration).
May Allah 'azzawajal help us all in all aspects of our life.
Answer: Best solution ever :
Say out loud right before you sleep (on the bed) : Surat Al-Ikhlass 112, then Surat Al-Falaq 113, then Surat Al-Nas 114, then Ayat Al Kursi (2:255), and lastly the last 2 verses of Surat Al-Baqara.
I guarantee you 100% that you will not have nightmares and dirty dreams in your sleep. They are nothing but the action of the devil (Shaytan).


Version 9 is not served to any device configuration: all devices that might receive version 9 would receive version 10

Question: I published a new version for my app with version 8. It published successfully. Then I realized there is a fatal bug, I immediately corrected it and tried to publish it with version 9. However, it saved it as draft and cannot publish it. I tried to delete the draft, also it cannot be done. I deactivated version 8 (buggy one) and uploaded new one, it is also saved as draft. So, I couldn't publish new one over version 8. People are still downloading buggy version and I could not do anything. Can you please help? Here is the picture
http://postimg.org/image/iokyc9js7/
Answer: Yes, firstly you should Deactivate the APK versioned 8, then the button "Publish" will be enabled again. You can click that button to publish your new APK. It works for me.


Asp.Net popup error message

Question: Is there a way I can display an error message in a popup box? I'm using Asp.Net (C#), and on our webpage, if an order goes throug incorrectly we display an error message. Now, we would like to be able to do so using some sort of pop-up method (maybe Ajax?) - it should be able to take a string value to display the error message.
Comment: What do you display to the user if the order goes through correctly?
Comment: They are directed to a new page that says "Thank you for ordering...." etc.
Comment: And if the order fails, are you going to keep them at the order page, or direct them to a new page?
Comment: Keep them at the same page, the order page.
Answer: For a simple approach, you can have a script block that contains alert("your error message"). If you want the popup to be styled as the rest of your website then you could render your error message into a div element and use a jQuery dialog to display it as a modal dialog within your page.
Comment: @OhMisterRabbit you can do this from code-behind: `Page.ClientScript.RegisterStartupScript(this.GetType(),"myalert","alert('There was a problem processing your order');",true);`
Comment: Can I display that using C# conditionally? If X then "display alert"?
Answer: I have used Ajax to accomplish this myself.
Using the ModalPopupExtender and setting  the PopupControlID to an Asp Panel, I usually put this into a User Control so it can be easily used through a website.
However below is a snippet of the asp.net code

    <asp:LinkButton ID="lnkConfirm" Style="display: none;" CausesValidation="false" runat="server" PostBackUrl="#">Confirm</asp:LinkButton>
    <ajax:ModalPopupExtender ID="lnkConfirm_ModalPopupExtender"  runat="server" TargetControlID="lnkConfirm" PopupControlID="pnlConfirmation" BackgroundCssClass="modalBackground" DropShadow="true" RepositionMode="None">
    </ajax:ModalPopupExtender>

        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>

                        <asp:Image ID="imgIcon" CssClass="modalPopupImage" runat="server" />
                        <asp:Label ID="lblMessage" CssClass="modalPopupMessage" runat="server"></asp:Label>

<asp:TextBox ID="txtValue" Width="200px" MaxLength="100" Visible="false" runat="server"></asp:TextBox>

                        <asp:Button ID="btnAction" runat="server" CausesValidation="false" CssClass="defaultButton" Text="OK"  />

            </ContentTemplate>
        </asp:UpdatePanel>

It does take some time to get it working properly as I have had a few errors with the script manager, which I currently have setup in a master page.
Just might give you a direction to head for, and the CSS can help shape and colour the message box.
Although this is a complex way in some respect but has many uses.
Comment: +1 for the ModalPopupExtender. I used that with great success before moving to MVC and jQuery.
Answer: You can do this with simple javascript like this...
alert("my error message");

Here is more info on using javascript

Asp.Net popup error message


How does the olam haba of a Noahide differ from that of a Jew?

Question: In other words, what precise reasons would motivate a gentile to convert rather than be a Noahide? I have heard that a Jew's olam haba is "better" but in what sense? What exactly is the difference?
Comment: @IsraelReader one could argue that the non-Jew has much more to overcome in order to keep his 7 as he doesn't have a Torah, or a minhag, or Torah keeping neighbours... nothing. Also one might be looking at it backwards. The number of Mitzvot Jews have is a privilege, not a burden, as such so simply counting Mitzvot isn't _necessarily_ relevant (although it actually is in quite a few different ways, I admit)
Comment: @jewishboy Does anyone know what the essence of Olam Haba actually is, so that we can then attempt to contrast the Olam Haba of the Jew vs. that of the non-Jew?
Comment: Do you think that the righteous gentile who only had 7 commandments to concern himself with, should be entitled to the same reward as the Jew who concernedly and meticulously kept the entire Torah? It's only fair that the extremely more effort of the Jew, over his lifetime, should be rewarded accordingly.
Comment: Clearly no one knows.
Comment: My question does not refer to their entitlement to a equal, greater or worse reward but rather what is the reward itself.
Comment: @RabbiKaii In an ideal world, all the non-Jew's neighbors would share the same values as himself and would be committed to meticulously keeping the 7 commandments. They would have study groups to study the fine points of their commandments and they would all be in this together.
Comment: @RabbiKaii The number of Mitzvot Jews have, is indeed a privilege, but also comes at the price of increased Yetzer Hara harassment. Having to deal with the hassle of a relentless Yetzer Hara, and the risk of messing up on any one of the numerous commandments, requires extra effort from man, and Hashem surely rewards man for every effort he makes to keep His Torah. לפום צערא אגרא.
Comment: @IsraelReader touché
Comment: @jewishboy It's a fair question overall, however it is impossible to answer from a jewish point of view as from said view it makes no sense. Judaism's goal is not for us to earn Olam Haba, our goal is to serve Hashem. So saying "why would someone prefer Judaism" based around a question of Olam Haba is a non starter
Comment: @RabbiKaii "Judaism's goal is not for us to earn Olam Haba, our goal is to serve Hashem." The Mesilas Yesharim (beginning of Chapter 1) seems to contradict what you're saying.
Comment: @IsraelReader that would require a discussion, feel free to open one and bring an exact quote and we can see
Comment: @RabbiKaii Done. https://judaism.stackexchange.com/questions/133750/mans-duty-in-this-world
Comment: @IsraelReader I answered there thank you. As for how that pertains to this discussion, see the connection with what I wrote here: https://judaism.stackexchange.com/a/133775/31534
Answer: I think that the question is likely one that couldn't be understood properly because even if you would ask what is it like to have a Jewish Olam Haba everything would be in parables and not capture the essence.
At the end of the day, Rav Dessler (See חלק א׳ שכר מצוה) points out that there is more joy from the "smell" of Olam Haba then there exists in the world from beginning to end (ie: if it was all "added" together). So nothing can capture or comprehend this.
My basic understanding is that there is a nuanced difference in that of proximity to Hashem. So for example a Jewish person may be closer in connection/proximity to Hashem. My guess is that this all depends on how great you are in your role, demands, and abilities.
For example I find it hard to accept that I have earned a closer place then Noach, Eve or Adam etc... There are likely many non-Jews who earned to be closer than me who are alive today.
I do think that obviously someone who wants to be closer will do more, but at the same time there is a balance between taking on too much and not willing to do those commandments he already has or break new requirements that he took upon himself.
So the motivation is being able to serve Hashem in more Mitzvos, to perfect oneself more, and be closer to Hashem. For example a non-Jew cannot keep the Sabbath. Torah is prohibited to be taught to a non-Jew (seek a Rabbi to know what can be taught to a non-Jew).
I think deciding to join the religion because you will "gain" more, although a normal human thought, should not be the approach. I don't blame the question though because it is a natural factor and thought. In fact in this world, Jewish people are routinely hounded and hated so in this world you might lose quite a bit which begs your question of the next world. Nevertheless, the approach should be to serve Hashem out of a desire to serve him and not a desire for reward.
Comment: *I think that the question is likely one that couldn't be understood properly because even if you would ask what is it like to have a Jewish Olam Haba everything would be in parables and not capture the essence.* Exactly what bothered me about the question. What makes Olam Haba "good" in the first place? What makes anyone's portion than another? The issue of how it applies to a Noahide is missing the forest for the trees.
Comment: @shmosel schar mitzva mitzva. The reward of Olam Haba is the discovery of how much the Mitzvot we did meant to Hashem (what other reward would we accept? We accepted Hashem as our God b'mesirat nefesh). This is something we can't know until He tells us (if He hasn't already, which He seemingly mostly hasn't, it's all a big secret)
Comment: @shmosel I agree; however, there is some truth to the question as we are told that we will be "burned" with the agony of what we could have accomplished when we see what others accomplished. (Messilat Yesharim discusses this). So there is truth to the question, but... it's ironically somewhat self defeating to do things for reward. So it's a component but not really the goal I suppose. I definitely think an interesting question though.
Answer: To answer what the difference is between a Jews and a Gentiles olam haba we must understand the differences between a Gentiles soul vs a Jews soul:
I got this idea from: https://www.etzion.org.il/en/philosophy/issues-jewish-thought/issues-mussar-and-faith/jews-and-gentiles and just took the part needed for the answer:
"The Alter Rebbe in Tanya (Tanya), chapters. 1–2) explains that a Jew has two souls – a G-dly soul, which partakes in some fashion in the actual substance of God Himself, and an animalistic soul, which descends from klipat noga, the evil that contains within it an admixture of divine light. Therefore, he explains, any good character trait found in a Jew reflects the essential goodness found in his soul. The soul of a gentile, however, according to the Tanya, is purely animalistic and not Godly. It descends from the evil forces that have no potential for goodness in them whatsoever. Therefore, any good deeds performed by gentiles are done for ulterior motives and cannot possibly reflect essential goodness.
According to this philosophy, a gentile is not merely a lower form of life, but is essentially and irredeemably evil; his substance derives from the sitra achra, the evil forces that threaten all goodness and purity in the world (Zohar, introduction, p. 13a)."
Look here: https://hakirah.org/Vol%2016%20Balk.pdf for more approaches on the difference between a Jewish soul and Gentile soul.
Based off this we can understand that a Jewish soul has its source higher spiritually and as we will see now gets more reward than a Gentile:

As explained the Jewish soul is more pure and spiritual (as we said above)
A Jewish soul is commanded 613 mitzvot vs 7. So for following more commandments from G-d Jews get much closer to G-d by developing a relationship in everything physical they do.
Based on number 2, the idea of גדול המצווה ועושה (brought down in many places in Shas e,g Bava Kamma 87a), that even if Gentiles were to do things they were not commanded (and also not forbidden to keep e.g Shabbat, learning Torah) they would get less reward then Jews who are commanded to do so.

Therefore the one difference in reward in Olam Haba based off the above is the Gemera in Brachot 17a (there could be more I'm not aware of) which says:
מַרְגְּלָא בְּפוּמֵּיהּ דְּרַב: לֹא כָּעוֹלָם הַזֶּה הָעוֹלָם הַבָּא. הָעוֹלָם הַבָּא אֵין בּוֹ לֹא אֲכִילָה וְלֹא שְׁתִיָּהּ
וְלֹא פְּרִיָּה וּרְבִיָּה וְלֹא מַשָּׂא וּמַתָּן וְלֹא קִנְאָה וְלֹא שִׂנְאָה וְלֹא תַּחֲרוּת, אֶלָּא צַדִּיקִים יוֹשְׁבִין וְעַטְרוֹתֵיהֶם בְּרָאשֵׁיהֶם וְנֶהֱנִים מִזִּיו הַשְּׁכִינָה, שֶׁנֶּאֱמַר: ״וַיֶּחֱזוּ אֶת הָאֱלֹהִים וַיֹּאכְלוּ וַיִּשְׁתּוּ״.
"Rav was wont to say: The World-to-Come is not like this world. In the World-to-Come there is no eating, no drinking, no procreation, no business negotiations, no jealousy, no hatred, and no competition. Rather, the righteous sit with their crowns upon their heads, enjoying the splendor of the Divine Presence, as it is stated: "And they beheld God, and they ate and drank" (Exodus 24:11), meaning that beholding God's countenance is tantamount to eating and drinking.
The Ben Ish Chai (in the commentary Ben Yehoyada) explains this Gemera in following way:
….That the עטרות are placed upon those who learn Torah, because from the lights of the mitzvah one is gramented in expensive garments, and from the lights of Divrei Torah one is made crowns, etc.
Based on this Ben Ish Chai we can explain that this cannot be referring to Gentiles since they are chaiv mitah (death penalty) if they learn Torah (Sanhedrin 59a). Hope this helps!
Look at these links for more information:
https://www.etzion.org.il/en/philosophy/issues-jewish-thought/issues-mussar-and-faith/jews-and-gentiles
https://www.torahmusings.com/2015/10/do-non-jews-get-reward-for-mitzvot/
https://hakirah.org/Vol%2016%20Balk.pdf
Comment: Sorry, my friend, but I have to differ on your understanding of Tanya. Firstly, don't translate "ra" as evil (the klipat nogah is also an admixture of ra!). It just means absence of Godliness. Secondly, I can't agree with "irredeemable", and I don't see anywhere in Tanya where it says that. Chabad philosophy indeed overall wouldn't support the above,  answer, as they assert non-Jews are Hashem's children too, and are made in the Divine Image and therefore not a "lower form of life" ch'v. Why they have been placed in a lower starting place is another discussion, see Shaar HaGilgulim 12:2
Comment: Thanks for your comment, these are not my words but from the website I quoted above (probably should have put them in my own words), I agree with the idea that ra isnt evil and the word irredeemable is also not the right word. The basic answer I was trying to say was that the Jewish soul is more pure, refined, and spirtual vs a gentile, and we can see that therefore a Jew will get a better olam haba based off the Gemera in Brachot 17a and the Ben Ish Chai that I brought which is actually the main answer.
Comment: @AvishaiTebeka I presume that Noachides have their own Torah and Mitzvot, so even with the Ben Ish Chai it is interesting to mix the Gemara Sanhendrin especially, since Rabbi Meir says a non-Jew who learns his Noachide Torah is like the Kohen Gadol, implying they are rewarded (and maybe even vested with garments)? I am not saying this is true, but your answer seems to be quite intense....
Comment: @msj121 thanks for your comment as well, I know that my answer is quite intense and many may disagree with it (here are other opinions as well:  https://hakirah.org/Vol%2016%20Balk.pdf) however I believe the concept makes sense.  With regarding to Rebbi Meir in Avodah Zara 3a Tosfoat in Senhedrin 59a says Rebbi Meir was referring to the seven Noahide laws and not the entire Torah (see Meiri who argues). Therefore from the Gemera in Brachot 17a combined with Sanhedrin 59a and the Ben Ish Chai we can understand that Jews have a greater Olam Haba.
Comment: And even the fact that Rebbi Meir says its like wearing Kohen Gadol garments for only 7 mitzvot, how much greater are the garments of Bnei Yisrael who keep 613 mitzvot!
Comment: @AvishaiTebeka I agree, in fact a non-Jew to learn other Torha is Chayav Mitta. However, the Ben Ish Chai and Tosfot would prove the exact opposite logic to what you have written...
Comment: @msj121 please explain how its the opposite logic
Comment: @AvishaiTebeka You can see my second answer.
Answer: To give another answer opposite Avishai:
Although a non-Jew can only learn Torah that are his necessary areas other areas are prohibited (with the seriousness of death), with that:
See Sanhedrin 59.

Rabbi Meir would say: From where is it derived that even a gentile who
engages in Torah study is considered like a High Priest? It is derived
from that which is stated: "You shall therefore keep My statutes and
My ordinances, which if a man does he shall live by them" (Leviticus
18:5). The phrase: Which if priests, Levites, and Israelites do they
shall live by them, is not stated, but rather: "A man," which
indicates mankind in general. You have therefore learned that even a
gentile who engages in Torah study is considered like a High Priest.

We can see that the High Priest is an extremely high level and connection with Hashem, in fact he goes into the Holy of Holies on Yom Kippur where angels are not allowed. This is the connection a non-Jew can have.
However, if this is the connection and value a non-Jew can have with only some of the Torah imagine what facets and connection are being missed with all the additional Torah available. See Avishai's answer showing Torah learning and World to Come are connected.
As per any mitzvah bringing Olam Haba:
Rambam Mishna Macot 3:16
מעיקרי האמונה בתורה, כי כשיקיים אדם מצווה מתרי״ג מצות כראוי וכהוגן ולא ישתף עמה כוונה מכוונת העולם בשום פנים, אלא שיעשה אותה לשמה מאהבה כמו שבארתי לך, הנה זכה בה לחיי העולם הבא.
Rambam, in his commentary to that Mishnah, explains that if one does a mitzvah properly he earns the world to come. I see no reason why the 7 laws would be different.
Comment: Although I can see how a gentile who learns Torah is like a Kohen Gadol who can get to such lofty level as you mentioned, we are speaking about Olam Haba (in the question asked), how do you know that a gentile can get a good/rewarding olam haba just by being "considered a kohen gadol?" Also, I don't see how this answer addresses the question of, how we know that Jew's olam haba is better? In other words, its not so clear from the Gemera you brought
Comment: Any mitzvah brings one to Olam Haba... I have included a source to satisfy you. My answer implies that a Jew's Olam Haba is greater due to greater amounts of Torah.
Comment: Now its more clear to me what you were saying, thanks


Simulate Infinity mirror effect

Question: I'm trying to model an infinity mirror but can't seem to get the reflections working correctly. I have a simple node setup of a glossy and transparent into a mixed node and the geometry node connected using the backfacing node to the FAC of the mix shader. I only have one "layer" of reflection ... how can I get the mirroring effect of infinity.
Comment: Possible duplicate of [How to setup shaders for semitransparent mirrors?](http://blender.stackexchange.com/questions/36388/how-to-setup-shaders-for-semitransparent-mirrors)
Answer: I think your node setup might be reversed, you probably want the glossy shader in the upper slot of the mix shader.
Anyway it may not work that way, if I understand correctly you may need a reflective 'lid' on your box so there's something else for the ground to reflect. Also since 'inside' your box it's dark so there is no light to reflect. Even though it's backfacing is transparent seen from inside it is all mirror so no light is getting in. If you add a light to the inside of your box it might work.

One side note if you are aiming for a 'infinity mirror' effect you may want to bump up the number of reflective bounces for cycles under the Properties Window > Render Tab> Light Paths > Bounces Glossy otherwise after that number of bounces cycles will return black instead of the actual reflection.
Answer: In Render Option in Light Paths panel, select Full Global Illumination in a intergrator presets dropdown, that will increase glossy bounce number and , total  bounce number
Comment: Adding a plane - glass and transparent shader as a lid and bumping up  the reflective bounces helped immensely as suggested by Duarte Farrajota Ramos. Adding a light only added a firefly issue and wasn't needed anyway. The effect was almost there. Changing the Light Path panel intergrator preset to Full Global Illumination completed the infinity effect.

Simulate Infinity mirror effect


How do you export a .blend group

Question: I've built a model in one project and want to import it into another. I see .blend files with groups that other people made. You click in the .group, get the item and you're all good to go. .. There don't seem to be any instructions anywhere on how to get it to make a group.. I don't want to export to unity or cad or anything like that - just simply move a model from one blender file to another. This must be possible. Any idea on the settings?
Comment: what you need is either File > Link (Ctrl + Alt + O) or File > Append (Shift + F1).
with Link, you can import anything from A.blend to B.blend: objects, materials, etc. - but you can't edit the imports inside B.blend. however, any changes made inside A.blend to whatever was Linked, will propagate through the Link and reflect on B.blend.
Append is the opposite of that. you import a COPY which you can edit and there's no edit-propagation from A.blend to B.blend. hope this helps :]
Comment: So you just want to move one object from one file to another?
Answer: The ~.blend file you wish to import must first include a group, which you create in your original project file, by any of the normal means of creating a group: selecting the elements you want in the group, and selecting the menu item Object > Group > Make Group when the viewport is in object mode, or using the defined shortcut key for this, CTRL-G, or alternatively by using the "add to Group" options under the Group pane in the "object properties" tab of the properties editor. If a group is defined in the file you are wanting to append or link from, when you select the append or link option in the files menu, after selecting the file, you will see in the list of items you can append or link, a listing for "group". Select this, and select the desired group, just as you would another data type, e.g., object, mesh, or material.

How do you export a .blend group


Eclipse is invisible in system tray

Question: I just installed Eclipse, but I got a problem, after I minimize the Eclipse than it's not visible on system tray. I also check the ALT+Tab but there also isn't visible. I had to kill the process and restart. How can I fix this?
Answer: Press Super+w
It spreads all the windows in current workspace.
You dont have to kill the application
Answer: Finally I figure it out:
I removed the eclipse:
sudo apt-get --purge remove eclipse
sudo apt-get autoclean

I installed again:
sudo apt-get install eclipse

And it's working now. I have no idea why didn't work before, case I have deleted the old ubuntu(10.04) and I installed the 12.04 from scratch.

Eclipse is invisible in system tray


TERM system environment variable not set - Windows 10

Question: So by mistake I deleted a bunch of my environment variables...
The one I cannot make sense of is TERM, a system-variable. Is this supposed to refer to the windows terminal? What value should I set it to?
Answer: That's fine. Regardless of the OS, TERM should never be defined system-wide.
In general, environment is a per-process thing. Both the "system" or "user" lists are only used to initialize the environment variables at login time, but afterwards the "current" environment is copied from parent process to child process, and each process could alter its own environment without affecting the rest of the system.
The purpose of TERM is to describe which terminal type is connected to the input/output of this specific process. TERM is meaningless for graphical programs (including even the terminals themselves), and can vary in value between terminals as they have different capabilities. For example, if you have Xterm and Urxvt running side-by-side, you will see "TERM=xterm" in one but "TERM=rxvt-unicode" in another.
Because of that, only the terminal app itself should set TERM for its child processes. (I'm not sure if that's possible with Conhost on Windows, due to it being a child of the console app rather than the parent.)

The Ncurses terminfo database has the ms-terminal TERM definition for the Windows Terminal app, although xterm or xterm-256color is "compatible enough" (it's what most apps understand, so it's what most new terminals try to emulate).
Similarly, MinTTY (the Cygwin Terminal) has the mintty terminfo file in Ncurses, but is also mostly xterm compatible. The Windows console (Conhost) would probably use ms-vt100+ or ms-vt100-color.
(That being said, apps running locally on the Windows Terminal will usually work without TERM, either because they already know they're running on Windows, or because they assume the entire world is xterm-compatible, or because they don't use terminal emulation in the first place (i.e. they use the old Windows "console" APIs). When you 'ssh' to another host, however, the SSH client should send a TERM value to be set on the server.)
Answer: TERM is widely used in unix-based systems, but it's not in use in Windows. You don't need to set it (my Windows 10, a pretty standard development machine, doesn't have it).


How many words/phrases were coined by Milton?

Question: In studying the works of John Milton in The Riverside Milton, I've noticed that the footnotes repeatedly point to the OED, which cites Milton as having coined a seemingly endless number of words and phrases that are still in use today. Knowing that he was fluent in Greek, Latin, Hebrew, Spanish, French and Italian, I've become extremely curious: Does anyone have a clue as to how many words/phrases Milton contributed to the English language?
Answer: This source claims Milton coined 630 words (to Shakespeare's 229):

According to Gavin Alexander, lecturer in English at Cambridge university and fellow of Milton's alma mater, Christ's College, who has trawled the Oxford English Dictionary (OED) for evidence, Milton is responsible for introducing some 630 words to the English language, making him the country's greatest neologist, ahead of Ben Jonson with 558, John Donne with 342 and Shakespeare with 229.
Comment: @oosterwal: Let's wait 400 years before we count those. See how many last that long.
Comment: @Erik: If that helps you, consider accepting the answer by clicking the checkmark (or upvoting it). It will mark you as a good citizen on this board and people will be more likely to answer your questions in the future.
Comment: I'm new here, so I checkmarked it (can't upvote anything yet).
Comment: I wonder how many words Snoop Dizzle coined...


Tapping background to close subview in Xcode 4.3

Question: Currently I am creating an app. for the ipad that uses a media player. When you click on a button the media player pops up and I have code that when you press another button the media player stops and is hidden so you can go back to using the superview. The problem is, I dont want to have to click a button to close the subview, I want to be able to click anywhere on the background to close. I've tried making the whole background a button but I'm having trouble writing code to make it so that the full window button that closes the subview ONLY appears when the subview is up. Right now the full window button is up constantly so I can't click on the button that brings up the subview in the first place because the large button is overlapping. I hope this dilemma is fairly easy to understand. If not I can send some code.
Answer: Try a UIPopover instead.  What you're describing is the default behavior.
Comment: I'll give it a shot and get back to you. As a novice programmer I may need more guidance but I'll see what I can do. Thank you for the help


Can I interchange fall down for fall off?

Question: If I say, I was on my motorcycle and I fell down, Would you still be able to understand? How weird does it sound? While on my bike, my trunk is in an upright position and literally I will fall in a downwards direction towards the ground so, is it absolutely necessary to say fall off?
Comment: It depends exactly what you're doing: there are many ways to fall off a motorbike and different expressions may be used for different falls (when it's stationary and you can't hold it upright, if you hit something and go over the front, if you fall off the side without the bike tipping over, or you hit a branch and go off the back, or many more.)
Answer: There are slightly different connotations:

"While riding the motorcycle, I fell off," implies that I was sitting, perhaps on the rear seat, and slipped off whilst the vehicle stayed upright. (Anecdote: a friend was trail riding alone, was knocked off by a branch, and saw his cycle proceed for another fifty-or-so meters sans rider.)

"While riding the motorcycle, I fell down," implies that I fell, and (likely) the vehicle did also. It depends on context, though.
Comment: because you become one with the bike?
Comment: In AmE, "fell off" doesn't usually imply that the vehicle stayed upright. As long as buttocks are no longer resting on seat, we can (and often do) use that phrase.
Comment: Quique - Because _fell down_ doesn't carry the implication of 'becoming separated from the thing you were sitting/standing on'.
Answer: In natural conversational speech, I wouldn't usually say fall/fell. If it refers to a motorcycling accident, I would say I/he/she/they came off the bike.
Here are some examples from newspaper accident reports:
"The 69-year-old came off his bike at the corner of Wrexham Road and Lawrence Hargrave Drive."
"British rider came off his bike at the corner where a Portuguese racer died last"
"A motorcyclist came off his bike at the Shepherd and Flock roundabout"
...


$F=\frac{dp}{dt}$ or $F=ma$?

Question: The second law of Sir Isaac Newton or also known as the fundamental relation of dynamics :
$$\vec{F}=m\vec{a}$$
Which can be derived using the definition of the force :
$$\vec{F}=\frac{d\vec{p}}{dt}$$
But only if $m$ is treated as a constant. What if $m$ is not a constant? absolutely we're not having the same result. Then what we must apply $F=ma$ or $F=dp/dt$ ?
Answer: In classical mechanics mass is always a constant. Matter is conserved (it gets a little more complicated in relativity and quantum mechanics but that need not concern us here). When dealing with a question involving "variable mass", for example rocket propulsion, one must divide the mass into the parts which are moving differently.  See e.g. Rocket equation. The force accelerating the rocket is $ma$, where $m$ is variable. It is NOT $ma + v\dot m$
Comment: This answer should be awarded 'correct answer'. +1 from me.
Answer: if m=const both are the same, if m ist not constant like in rockets you have to use change of  impulse .

$F=\frac{dp}{dt}$ or $F=ma$?


What happens to unstrapped passengers if the airliner were to fly inverted

Question: If for some reason or the other, because of an emergency, or perhaps craving jail time or did not want her job, or perhaps a girls will be girls moment, a pilot and her captain decided to fly a large aircraft like the A380 or boeing 747 inverted and some passengers decided not to strap on their seat belts per instruction in protest of the girls will be girls stunt, what would happen to the unstrapped passengers if the pilots flew this aircraft inverted for a minute or so at its maximum flying altitude?  Would they land on the ceiling, because acrobatic pilots seem not to when they fly inverted.  Will this aircraft land safely?
Comment: I'm voting to close this question as off-topic because it is not a "practical, answerable question based on actual problems that you face" ([Help centre](https://aviation.stackexchange.com/help/dont-ask)).
Answer: That depends on how the pilot inverted the aircraft. If they pulled a Tex Johnson and executed a smooth barrel roll everyone would remain in their seats as it is a 1G maneuver. Even the flight attendants pouring drinks wouldn't spill.
If the Pilot executed an aileron roll the situation would be quite a bit different...
Answer: You don't see aerobatic pilots hit the roof for two reasons:
When aerobatics are planned and intentional, the pilots are strapped in tight by the seat harnesses (usually 4 or 5 point harnesses). During sustained inverted flight, their harness hold them in their seat.
For simple, quick maneuvers, such as a barrel roll, the maneuver can be be done so that the acceleration will always be "down" relative to the airplane (towards the seat), even when the airplane is upside down.   This is the same principle as swinging a bucket of water over your head and the water doesn't immediately fall out.

In the case you created, it is possible for a wide-body / heavy plane to do a barrel roll and be inverted briefly so that passengers don't fall out of their seats.  Test Pilot Tex Johnson famously did a such a 1G roll in a 707 (although without passengers).
If the flight were sustained inverted flight, however, everyone not strapped down would hit the ceiling.
Answer: Yes, they would land on the ceiling if not strapped in.  It is basic physics.  Aerobatic pilots strap in before flying inverted.
Provided the aircraft rolls back upright first, it should be able to land safely.
Comment: To be fair the question was ill posted. I need to read again to see OP thinks some pilots don't look to strap themselves while doing stunts. That's wrong because recreational pilots are not acrobatic pilots and both are straped
Comment: Yes, I agree... not a well thought out question.
Comment: There was an Alaskan Air aircraft that lost its jack screw and flew inverted for a short while. I believe, though, that the fuel lines lacked the means to deliver gas from inverted fuel tanks and basically ran out of gas and went nose first into the Pacific Ocean.


PHP strtotime() looks like it is expecting a Euro format

Question: I've been using PHP's strtotime() method to accept a date field on a form. I love how powerful it is, in how it will accept "Tomorrow", "Next Thursday", or (supposedly) any date representation and convert it to the Unix timestamp.
It's been working great -- until yesterday. Someone entered "2-4-10" and instead of logging Feb 4th, 2010, it logged April 10, 2002! So it expected Y-M-D instead of M-D-Y.
I thought maybe the problem was just using a 2-digit year, so we tried again with "2-4-2010". That logged April 2nd, 2010! At that point I just don't understand what strtotime() is doing. PHP.net says it expects a US English date format. Why then would it assume D-M-Y?
Is there a way around this? Or do I have to stop using strtotime()?
Note: I just now did a test. When you use slashes instead of hyphen/dashes, it works fine, even with 2/4/10. Why on earth does that matter? And if that's all it is, should I just run str_replace("-", "/", $input) on the form input before passing it to strtotime()?
Comment: Yes, attempting to normalize the date in some way before processing it with strtotime seems like a good idea to me.
Comment: Just wait until you try to use strtotime to parse *times*, then you'll be having some real Fun. (Think timezones, DST, etc.)
Answer: The - indicates an ISO Date:
03-02-01  => 1. february 2003 (ISO)
01.02.03  => 1. february 2003 (European)
02/01/03  => 1. february 2003 (US)

Answer: The behavior of strtotime() is based largely on the GNU date input formats spec. But as powerful as it is, it shouldn't be expected to read minds. Allowing free-form user date input is asking for perpetual trouble.
Answer: I had this problem and solved it by doing exactly what you suggested - do a str_replace on the user-entered date to replace the dashes with slashes.  This prevents strtotime from using an ISO date and solves the problem.
Answer: strtotime is by its very nature fuzzy, so you can't assume that it will always do what you want. If you enter 2010-04-02 then you would expect that to return 2nd April 2010, which is what strottime is trying to do. Running an str_replace from hyphens to slashes might mean that people entering in that format get the wrong date.
If you're running PHP 5.3 or above, consider date_parse_from_format() or for PHP 5.1 and above on Unix consider strptime(). Both functions take a format, so remove potential ambiguity (if you tell users what format you are expecting - if you're running an international site and have a text box labelled date which the user enters 2/4/2010 into then there is no way to know what their intended date is).


Why is the window description coming like this when I press Super key?

Question:
The window title should appear beneath the window, not on the top. How do I fix this ?
Answer: try adjusting some custom settings in "settings manager" -> "windows manager" / "windows manager tweaks" / "appearance"
Many ways to customize the look/style etc...
Comment: Do you mean the "Onboard settings" ?
Comment: no - i believe "onboard settings" is a keyboard map/macros for on-screen keyboards...     I am referring to the general settings gui. Depending on your distro the names may vary slightly.
Comment: Oh i got what the problem was. In the tweak-tool I had activated the native window placement option and this was causing the problem.
Answer: The problem lied in an option I had activated in gnome-tweak-tool. It's in extensions and named Native Window Placement. When it was activated the behavior which has been captured in the image was shown. It is meant to arrange windows in a compact manner. When it is deactivated, the window title text takes up space and places it beneath which is the default behavior.


Transfer file from server to home computer via another server

Question: I have a text file on the server (Linux) at work and now I am at home. I am a PuTTY user. To connect to the server from home I have to connect to another server and then by SSH to the main server (which means I can connect to the server at work, indirectly from home) so I can't use scp command or WinSCP to transfer or copy my file to my computer at home. Does anybody know that how I can transfer or copy my file from the server at work to my home computer (Windows system)?
Comment: Can you set up a [port forward](http://howto.ccs.neu.edu/howto/windows/ssh-port-tunneling-with-putty/) to the main server using PuTTy? If so, you could start a direct connection with the server (through the port forward) and use SCP to copy the files.
Answer: You could always transfer files to the intermediate server and then copy it from there. However if the intermediate server has space limitations and cannot hold large files, then you need to create a tunnel through the intermediate server to the second server.
Creating a tunnel through putty,
1) your ssh config should point the intermediate server like this:

2) Then go to Connection -> ssh -> tunnels, you can use any port on your pc for source port, I've entered 8080 here, and in the destination enter the company server which is accessible through the intermediate server as companyServer:22 and hit add.

3) Hit open, it should ask you the credentials for your intermediate server. Once this is done, you can open your scp client like winscp and point it to  at port 8080. This connection will be forwarded to your company server's port 22, where the sshd will be running.
Answer: You are looking for SSH tunneling (as other answers pointed out).
Note that WinSCP supports a (one hop) tunneling natively, so you do not need to bother with setting up a tunnel in PuTTY.
See the Tunnel page on WinSCP Advanced Site Settings dialog.
Answer: If I understand your scenario right, you are saying that you have to connect to one computer via SSH, and then connect to another computer from there?
If so, why not log in to the first server, and then run scp mainserver:file.txt ./. Then log out, and run scp firstserver:file.txt ./ to get it from the first server. You can then log in to the first server and delete the file.


ARCGIS IOS Development Delegates Not Connecting/Working

Question: I'm new to ARCGIS so be easy on me.
I have an UIView in my nib which I changed into an AGSMapView which I then referenced in my UIViewController class which also holds the <ArcGIS/ArcGIS.h> package. Okay I think I've done everything right so far.
After running the code below in the viewDidLoad, I can add the view to get the map to appear on the simulator.
NSURL* url = [NSURL URLWithString:kTiledMapServiceURL];
AGSTiledMapServiceLayer *tiledLayer = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL:url];
[self.mapView addMapLayer:tiledLayer withName:@"kTiledMapServiceURL"];

From here I want to access the - (void)mapViewDidLoad:(AGSMapView *) mapView so I can add the users location.
Anyways I add the AGSMapViewLayerDelegate and set self.mapView.layerDelegate = self;.
Now my code looks like something below.
- (void)viewDidLoad
{
[super viewDidLoad];
NSURL* url = [NSURL URLWithString:@"http://services.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Base/MapServer"];
AGSTiledMapServiceLayer *tiledLayer = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL:url];
[self.mapView addMapLayer:tiledLayer withName:@"Basemap Tiled Layer"];

self.mapView.layerDelegate = self;
}

- (void)mapViewDidLoad:(AGSMapView *) mapView
{
 [mapView.locationDisplay startDataSource];
}

Anyways for whatever reason I can never get mapViewDidLoad to be called, or for that matter any other events in ARCGIS. I believe I'm doing everything I should, If anyone has any ideas why this is occurring, I would greatly appreciate them.
Answer: Well, it is possible that you don't adopt the protocol  to your View Controller like:
ViewController: UIViewController <AGSMapViewLayerDelegate>


Parity transformation on the adjoint spinor

Question: In eq. (3.128) of page 66 of "An Introduction to QFT", by Peskin & Schroeder, a step involves:
$$P\,\overline{\psi}\left(t,\textbf{x}\right)P^{-1}=P\,\psi^{\dagger}\left(t,\textbf{x}\right)\gamma^0P^{-1}=P\,\psi^{\dagger}\left(t,\textbf{x}\right)P^{-1}\gamma^0\,.$$
Without knowing a priori the form of matrix $P$, except that it reverses the momentum of a particle without flipping its spin, how can I justify that $P$ commutes with $\gamma^0$ as suggested by Peskin & Schroeder?
Comment: We get asked this exact same question at least once a week. $P$ and $\gamma^0$ act on different vector spaces, so they commute. Do we have a canonical question on this? I never know which one to link to...
Comment: I was expecting this answer concerning the different vector spaces and I'm glad you gave it, since it pertains to my real doubt:  at some point, we conclude that $P$ is of the form $P$ = \gamma^0, which still entails the same commutation relations. However, they now live in the same vector space. Unless I consider that stating  $P$ is of the form above is unrelated to the space it acts upon. Am I correct?
Answer: Make both matrices diagonally dominate. Compute the product of the 2 matrices. If all of the vectors of the matrix are linearly independent, the matrices commute.


Nexus 7 and ethernet connection

Question: In places where there's no wi fi, wired internet connection is sometimes available. But reading around it seems there's a bug in my Nexus 7 (2013) - Android updated to 4.4.2 - that prevents an ethernet connector from working.
Is this correct? Has there been any response from Google about it - a firmware fix? I'm not really up to doing my own patching.
Answer: Many people have reported that Plugable's adapter works.

Nexus 7 and ethernet connection


Can the high current motor change the ground potential level in the H-Bridge?

Question: I'm planning a half-bridge driver with bootstrap IC-s. My motor runs on 12V, with 50-60A. I linked the schematic. I supply the bootstrap from an other battery (7.2V). Due to the big current, can the ground potential level change? In this schematic the ground of the batteries is connected to each other.  I fear that the potential level increase/decrease can damage the other part of the electronics, that is supplied from the 7.2V, too.
I found a datasheet: http://www.irf.com/product-info/datasheets/data/ir2184.pdf, where two types is introduced, a coupled (IR2184), and a decoupled bootstrap IC (IR21844). What are the advantages/disadvantages both of them?
Comment: 50 or 60 amps will probably produce a measurable voltage drop in everyday ground connections, yes.   You will have to decide if it is better to have control electronics "ride" that difference by being grounded near the load, or "see" that difference by having their own ground path back to the battery.  Also consider the effect of inductance if the load current has a pulsed character.
Answer: The answer to your first question is yes. Now regarding the two ICs:
First, with the IR21844 you can set the dead time. In the simpler IR2184 it's preset.
Second, the 21844 has separate ground pins for the driving logic (VSS) and MOSFET grounds (COM), which is probably what you refer to by 21844  being "decoupled". It is certainly advantageous for your high-current application, as this IR FAQ explains:

with the potential of generating higher -Ldi/dt voltage spikes on COM, later ICs separated Vss and COM to increase the noise immunity between logic and power grounds, so that voltage spikes on COM did not cause the logic ground to dip below zero volts and generate false input signals. In these cases separate Vss and COM pins are provided.

On the downside, the 21844 needs more external parts and probably costs more itself too (bigger package).
Comment: Also note that this [split COM VSS] is not a unique feature of [some] IR chips. Other manufacturers have adopted the same solution for similar ICs, e.g. http://www.ti.com/lit/ds/symlink/ucc27714.pdf
Comment: And for more background material, you'll want to google "ground bounce". A lot of what you'll find on that is about high-speed logic, where the currents aren't all that big but di/dt is. In high-current power applications, the speed may not be that fast, but the large difference in currents is going to have the same net effect.


How to save data in arduino when it's power goes off

Question: I am doing a project 'arduino based switch operation'. Here the user needs to set a time to turn on relay and set time to turn it off. The problem is that I want to supply power to arduino using adapter connected to the ac supply (where the relay will also be connected). When the on time is set and if power goes off for some time then this system doesn't work. I want to save the data in arduino so that it will retain the data if power comes back.. So that my relay is operated on time..
How to do it guys???
Comment: See this answer https://arduino.stackexchange.com/a/72370/14490
Comment: Maybe I don't understand the question, but should the idea not be: the Arduino is always on, and the on and off time depends if the relay goes on/off... If you want the Arduino to be switched off too, you need at least some battery power and using sleep mode i.c.m. with an interrupt pin trigger set to some real time clock to be able to 'awake'  it.
Comment: It is unclear, if you want to power off the Arduino in regular operation, or if you just want to save the time settings in case of a power outage. Please make this clearer
Answer: Look up EEPROM. it is a memory that saves content even though power is off.
You can write data in EEPROM and when power comes back read it back.
there are safe ways to write in EEPROM without corrupting it.
Answer: Beside Georgi's answer, I would like to tell  you some details.
First :
a microcontroller can have a built-in EEPROM like the ATMega328 inside an Arduino UNO/Nano/mini, if not you would need to attach an external one, it can have may interfaces like SPI or IIC etc...
Second :
an EEPROM can hold only a specified amount of data, it can be 512byte like one on the ATMega328 microcontrollers, it can be only 64byte on others.
Third :
an EEPROM have addresses so for example in 8-bit EEPROM one address can hold only 8bits so values from (0-255) like on the ATMega328
Fourth : how to use it
In the beginning of your code you should first include the eeprom library
#include <EEPROM.h>

Then you would for example assign value "24" to one of the address on the EEPROM let's say address "1"
So you will use
EEPROM.write(1,24);

Of course you can power off you board and repower it again and that particular address will have the assigned 8-bit value "24".
To read back
EEPROM.read(24);

I hope that might help you or anyone else.
And as a side note an EEPROM have defined write and read cycles ~10000 maybe ~100000 after that amount it May not work.
Original documentation : here
Answer: You Can do that by using RTC (Real Time Clock Module ) in your project.
Comment: And *how* would you do that? "How do I get from New York to Trenton?" "You can drive." Hardly helpful.
Comment: Sure, hardly helpful. But similar to the question. The title question "How to save data in arduino when its power goes off" smells like EEPROM, additionally...