What are the weaknesses of WPA with TKIP?

Question: I am researching about the weaknesses of WPA with TKIP. I have an idea that the AES-CCMP mode is better than TKIP, but what are the weakest points of TKIP? Also, I am wondering about the disadvantages of WPA TKIP. What are the disadvantages over WPA-AES?
Comment: WPA-TKIP is very weak to DOS attacks.
Answer: Here's a relevant excerpt from a blogpost I did on here a few months ago:
WPA generally uses Temporal Key Integrity Protocol (TKIP). TKIP was designed by the IEEE 802.11i task group and the Wi-Fi Alliance as a solution to replace WEP without requiring the replacement of legacy hardware. This was necessary because the breaking of WEP had left WiFi networks without viable link-layer security, and a solution was required for already deployed hardware. TKIP is not an encryption algorithm, but it's used to make sure that every data packet is sent with a unique encryption key.
An excerpt from the aircrack-ng paper, Practical attacks against WEP and WPA:

TKIP implements a more sophisticated key mixing function for mixing a
  session key with an initialization vector for each packet. This
  prevents all currently known related key attacks because every byte of
  the per packet key depends on every byte of the session key and the
  initialization vector. Additionally, a 64 bit Message Integrity Check
  (MIC) named MICHAEL is included in every packet to prevent attacks on
  the weak CRC32 integrity protection mechanism known from WEP. To
  prevent simple replay attacks, a sequence counter (TSC) is used which
  allows packets only to arrive in order at the receiver.

There are two attacks known against TKIP:

Beck-Tews attack
Ohigashi-Morii attack (which is an improvement on
the Beck-Tews attack)

Both of these attacks only could decrypt small portions of data, compromising confidentiality. What they can't give you is access to the network. To give you an idea of how much data can be recovered, a single ARP frame would take around 14-17 minutes to get the plain text. Getting useful information with this type of attack is very improbable (but not impossible) considering the rate of recovery.
Answer: More recent attacks:
https://pure.royalholloway.ac.uk/portal/files/25512708/paper.pdf
http://www.rc4nomore.com/vanhoef-usenix2015.pdf
Background: WPA-TKIP uses WEP's key structure, changing the 104-bit key on every packet using key mixing. The 24-bit IV is however generated from the low 16-bit of a replay counter, which still created keystream biases in RC4. They are however much more difficult to exploit than WEP's keystream biases where the 104-bit key is always the same.
Answer: You can gain complete access to a WPA(2) + TKIP network, if there is a client connected.  It is trivial to deauth a client and capture the key exchange.  This functionality is built into aircrack-ng once you have the 4 way handshake you can simply run it against a dictionary file until you find the key.
Here is a link that walks you through the process:
https://web.archive.org/web/20160501103330/https://itfellover.com/9-wpa2-tkip-security-mode-cracking/
Comment: Dictionary attacks aren't "trivial". They take quite a while with average machines and even then only tend to work around 30% of the time.
Comment: in the statement the trivial part refers to sending a wifi deauth packet


.doIfEquals not working with gatling version 3.7.6

Question: I have been using the gatling version 3.6.1 in my application for the performance testing. Recently I upgraded the version to 3.7.6 and observed that all the conditional statements were not working.
The below doIfEquals condition is not evaluating to true even if the value of index variable, stored in session is 1. On reverting it to previous version, I am not running into this issue.
<code>.doIfEquals("${index}", 1) {
//logic
}
</code>
Answer: Already answered on Gatling community forum where this question was also posted: known bug, already fixed several releases ago.
Comment: Thanks. Upgrading the Gatling version to 3.8.2 helped.


How to fix ROBLOX "Error Code 17"?

Question: I keep getting error code 17 on ROBLOX, is there a way to fix it?
Answer: According to Roblox's support page:

Signs of Connection Problems
Roblox has trouble with or fails to load online games, sometimes
showing the player an error message (which can include "Could Not
Connect" or "ID=17 Failure" messages). Loading screen on the website
takes a long time or never finishes to load. Player can visit games in
the Build or Edit modes, but not in Play mode. Games randomly or
consistently tell you that they have shut down.

The site then has you try some basic troubleshooting to resolve that error:

Reset Your Internet Options (Windows Only)
Many times, a simple reset of your Internet Options is all you need. Please keep in mind that these steps will need to use Internet Explorer, but will fix many problems even for players that use other browsers such as Chrome or Firefox. Please try the following:

Open Internet Explorer (this browser specifically)
Open the gear icon > Internet options
Open the Advanced tab
Click the Reset button
Close Internet Explorer
Try playing again

Check Your Browser's Security Settings You will need to ensure that the security settings on your browser allow for Roblox. If these
settings are set too high, it can cause a variety of problems ranging
from what is listed at the top of this article to website issues such
as buttons/links not responding.
Check Wireless Connection You can rule out the wireless connection by switching to a wired connection if possible. If it's not the
connection, or if you can't try a wired connection, then check your
firewall's settings, which we will discuss below.
Remove/Disable Any Ad-Blocker Browser Add-Ons Browser Add-Ons/Extensions can cause a number of issues, and in particular,
Ad-blockers can stop a game from fully loading.
Make Sure the Appropriate Ports are Open The ports that Roblox uses is dependent on the Operating System used. The port range is
currently UDP 49152 - 65535, so keeping all these ports open should
allow Roblox to connect to your router properly.
Configure Your Firewall and/or Router A lot of antivirus or internet security software tries to control which programs can access
the internet. Often, these programs err on the side of caution and by
default no program is allowed access.
Reinstall Roblox

Otherwise, Contact Roblox's support.
Comment: iirc you don't actually need to use IE to change Internet Options--you can just type "Internet Options" into the Search bar and it'll pop it up.

How to fix ROBLOX "Error Code 17"?


What are the design principles implemented in DXA?

Question: In order to build a website faster we can use the DXA reference implementation. I would like to know if is there any documentation where it says why we need to follow this implementation, what design principles DXA uses and if any new design principles need to be introduced on top of DXA what will be the best approach?
Comment: I assume you have read the DXA docs? https://docs.sdl.com/784837/679194/sdl-digital-experience-accelerator-2-2/introduction-to-------------sdl-digital-experience-accelerator
Answer: You don't need to follow the reference implementation, it's just an example website, though it has some good examples and scenarios which can be recycled.
DXA is MVC in essence, so every design principle which is valid and proven in MVC will also perform well in DXA. There is a slight difference in DXA involving the "under the hood multi layer routing for various items (Page, Region and Entity)" and some related to how the Model is obtained (and cached (including rendered output caching)) so just keep those in mind when applying any design principles/choices.
As Rick has mentioned in his comment, a good place to start is the official docs, but also debugging through the reference implementation to get a better understanding about the DXA specific concepts and how they fit into any design choices.
Answer: Having implemented several DXA solutions for clients I recommend you take a look at the following DXA resources

DXA Demo Site by Bart Koopman
DXA Video presentation on SDL Docs
DXA Core Code on github
DXA Demo website Code on github

You can get a responsive MVC DXA site up and running using the DXA Models and DXA Views , you just need to add content and change the CSS to provide your house style.
OR
You can use the DXA Models and add your own Views ,if you don't want to use Bootstrap you don't have to.
You can add extra Models and Views to suit your specific use cases.
OR
You can write your own Models and Views if you need to. (You can easily auto-generate the Models and Default views based on your schema with PowerShell and Tridion Core service)
OR
You can even migrate an exiting site to MVC DXA by creating Models and Views based on the existing site schema.
DXA Region Views and Page Views help to avoid a proliferation of additional Controllers.
Whatever way you choose, I recommend that you take advantage of the Core Embedded schema for links and lists, plus make sure that you add the DXA Markup to enable Experience Manager from the start.
It will help if you get some DXA training from SDL or one of the many experienced Tridion Consultants so that you get a good implementation from the start.
The DXA reference implementation is a reference to show you how to build a standards compliant MVC responsive site which is supported by SDL and the SDL community. If you chose DXA then you will also be able to take advantage of the additional integration solutions provided by SDL and the SDL Community.
Answer: Adding to the very good comment from Atila, I thought I could expand on why the DXA was created in the first place, as that can help understand a few decisions.

There was no "out-of-the-box" implementation for Tridion that was somewhat modern (one could argue that CWA was such an implementation, but it was at least 10 years old back in 2015)
Everyone was re-inventing the wheel with the basics
It was hard to push out any sort of extension or basic site functionality if there wasn't at least one "this is how you should do it" implementation
DD4T - while probably superior, I don't want to get into that debate - did not have an end-to-end implementation, and focused on the under-the-hood functionality and not so much on the finished result.

There's more, of course, but the topics above drove the decision to create the DXA. From an application point of view, as Atila states, it was based on MVC, it uses a generic JSON data format (provided by DD4T libraries), and it tried to make it more "web-developer friendly" than what we had before.
Comment: I agree with you,Once I here DXA supported by SDL, i thought developers have common solution instead of re-inventing the wheel as you mentioned. Recently I saw DD4T team starting again as they faced issues with DXA and Trivident team released another framework Dyndle, I felt this may again create confusion among the developers which framework to use.
I thought if we document the design principals of DXA and suggest developers to follow similar principals (Sitecore has Helix) that may elminate future issues and if I want to combine some best practices from other farmeworks it will be easy


Is it possible to build 'Contra-rotating' EDF?

Question: Is it possible to design an EDF (Electric Ducted Fan), with two counterrotating blades, that will have more thrust than two separate EDFs with the same blades?
Comment: Would the blades have to be **exactly** the same, or may we consider that they can be optimized for each case? I'm guessing you'd like the diameter to be the same in both cases.
Comment: And just a guess because I can: one EDF with two counter rotating blades and X kw of power would produce less thrust than two separate EDF's with the same blades and X/2 kw of power each. Because the version with two EDF's will have twice the area of prop disc and the independend blades are operating in undisturbed flow. Just guessing, though...
Comment: Related: https://aviation.stackexchange.com/questions/66400/what-are-the-relative-efficiencies-of-the-various-stages-of-a-counter-rotating-p
Comment: Please feel free to 'design' each fan independently.  Include a stator, etc.  The inlet duct would probably be ~30% smaller in diameter, at the throat, than the first fan.  The exhaust would also have a diameter, at the throat, about 20-30% smaller than the 2nd fan diameter.  Be creative!!
Answer: The primary reasons you'd want contra-rotating pairs with conventional (unducted) propellers are cancellation of torque/P-factor, and delivering more power with a limitation on diameter (tip speed, usually, or landing gear height).
Neither of these really applies to ducted fans; it's easy to null out the slipstream rotation with fixed vanes in the duct, and flow is always perfectly axial so there's no P-factor to worry about.  Further, pitch can be built high enough to absorb the needed power without supersonic blade tips, and generally is.
Bottom line, there's nothing to be gained from the extra weight and complexity of contrarotating fans in a duct compared to just using a slightly larger fan and motor to deliver the increased thrust you're chasing.
Answer: Probably not. In general, a stacked pair of contra-rotating propellers produces somewhere around 70%-80% the thrust of the same two props if mounted separately (Peter Kaempf can tell you the exact number). This is true regardless of whether the props are turned by electricity or gasoline.
Comment: I am not a turbine engine expert.  What I am trying to accomplish is, I think, something similar to a jet engine's compressor.  I want to increase the pressure ratio, which should increase the overall thrust.  But, I'm just guessing - - - -
Comment: BTW, thank you all for your comments.
Answer: Inline, contra-rotating EDF do exist in the RC community but they are very hard to get right. What does not exist are inline EDF configurations that produce more thrust than the two EDF units mounted separately.
There have been many failed attempts to get inline EDF to produce more thrust than a single EDF but there have been several successful attempts.
In case the above statement escaped your notice let me rephrase it: a lot of attempts putting two EDF units inline fail to produce significantly more thrust than a single EDF. My own attempts got me around 0% to 10% more thrust while using around twice the current. It's hard to get it right. But some people have managed to get more than that.
Of those who've successfully flown twin inline EDF units the advantage seems to be not extra thrust but higher overall efflux speed. Generally the rear EDF would have a higher pitch fan so it can accelerate the output of the first EDF without slowing it down. You will end up with a heavier plane with almost no gain in thrust but hopefully a higher top speed.
The main problem is if you get the pitch of the rear EDF wrong then it will simply act as an airbrake instead of an accelerator (you will sometimes notice this phenomena with pattern planes and motor gliders - non EDF - where diving with the prop spinning is slower than with the prop stopped).
The following are some of the more successful discussions/articles from various RC forums over the years. Unfortunately a lot of original content on the results of some of the projects are no longer online but the forum thread is still there:
https://www.rcgroups.com/forums/showthread.php?262808-Electric-Ducted-Fans-November-2000
https://www.rcgroups.com/forums/showthread.php?83207-Multi-stage-EDF
https://www.wattflyer.com/forums/showthread.php?t=67783
https://www.rcgroups.com/forums/showthread.php?1674106-Two-edf-units-in-the-same-duct

Non-inline staged EDF
There is one interesting experiment that used two regular EDF fans one behind the other but is not inline. Instead the first EDF is installed in a cheater hole that blows additional air into the intake from above the plane. This also did not get twice the thrust but got more than the usual amount of almost nothing. You can see the video of it here:


Is there a difference between $y(x)$ and $f(x)$

Question: Oftentimes functions described by $f(x) = 2x+4$, and when this is mapped to the Cartesian plane, $f(x) = y$. This surely implies that $y = 2x+4$. Is there a difference between this and $y(x) = 2x+4$?
Answer: Functions vs. coordinates
Consider plots of two different functions: $f(x)$ and $g(x)$ on the same $xy$ plane. One curve will be labeled $y=f(x)$ which means "this is a set of $(x,y)$ points that satisfy $y=f(x)$ condition". The other will be labeled $y=g(x)$.
Which of these should define $y(x)$? Both? – certainly not, because $f$ and $g$ are different functions. I say: neither. The statement $y=f(x)$ is just a condition for some set of points (i.e. $(x,y)$ pairs) while $y=g(x)$ is another condition for another set of points.
Explicit definition in a form $y(x)=…$ does define a function (well, does or doesn't, read the next paragraph). In this case $y$ is just an arbitrary name and may replace $f$. The same symbol $y$ may be a coordinate on $xy$ plane, which was $xf$ plane before the name replacement. (It is only a custom to have $xy$ plane.) This "union" of function name and coordinate name may cause a problem when there is another function $g(x)$ to plot.
It should be obvious that if $y$ replaces $f$ it cannot replace $g$ that is different than $f$.
For that reason it is a good thing to have coordinates with symbols which are not function names.

Definitions vs. equations or conditions
Another problem: we often write function definitions the same way as conditions to be met or equations to solve. Compare the two:
$$cos(x) = \sum_{n=0}^{\infty} \frac{(-1)^n x^{2n}}{(2n)!} $$
$$cos(x) = \frac{1}{2}$$
The former may be treated as non-geometric definition of $cos$ function. The latter is just the equation to solve for $x$. We have some experience and often feel the difference, but a person (say: Bob) completely unaware of $cos$ will be confused. Bob may find every $x$ that satisfies
$$\sum_{n=0}^{\infty} \frac{(-1)^n x^{2n}}{(2n)!} = \frac{1}{2}$$
and still will not be able to tell what number $cos(x)$ is equal to for any other $x$.
It's worse than that! Bob cannot tell what number $cos(x)$ is equal to even for $x$ being his solution, because he cannot be sure that either equation defines the function (we know it's the first one, Bob doesn't). To clarify that, let's see what happens when I change $cos$ to $sin$ only:
$$sin(x) = \sum_{n=0}^{\infty} \frac{(-1)^n x^{2n}}{(2n)!} $$
$$sin(x) = \frac{1}{2}$$
We know by experience that neither of above defines $sin$. Yet these are legitimate equations to solve either separately or as a system (with empty set solution). Bob (not knowing about $sin$) may only assume that one of the equations is a definition – this will be wrong, his set of solutions will not be empty.
That's why I like the notation $f(x) \equiv …$ or the word "def" above the equality sign, or the explicit statement ("let us define…") – just to cut out possible ambiguity.
I've got the impression that you meant $y(x) \equiv 2x+4$ because there is no other expression in your example that you may want to define as $y(x)$.

Summary

Is there a difference between $y=2x+4$ and $y(x)=2x+4$?

My answer is: in general it may be. The second form is more likely to be read as a definition of a function, yet any form may or may not be intended to be a definition. Both may be equations to solve, when $y(x)$ is defined elsewhere ($y$ may be a given number or a parameter not depending on $x$, still it can be formally written as $y(x)$). The second form states that there is some function $y(x)$; the first one may mention a function or a variable (coordinate) $y$. The coordinate (not function) interpretation allows the first form to be a condition for points (i.e. $(x,y)$ pairs) – as it may be in your example – that leaves room for another conditions for another sets of points.

Is there a difference between $y=2x+4$ and $y(x) \equiv 2x+4$?

Yes. The second form defines a function for sure. The first one may have another meaning (explained above).

Is there a difference between $y \equiv 2x+4$ and $y(x) \equiv 2x+4$?

There is a subtle one: from the second form we know the independent variable is $x$; it may be $x$ xor $y$ in the first one.

Is there a difference between $y(x)$ and $f(x)$?

No. In a sense: you can name your function with any unused symbol. But if $y$ is already in use (e.g. to name a different function, coordinate, parameter) then you cannot freely rename $f$ to $y$.
Comment: This answer was very illuminating to me, especially since it was on a topic that I thought I was comfortable with. I particularly enjoyed your 2nd section, highlighting the important difference between equality and definitions/the distinctness of objects themselves. It seems like $ :=$ "$ \subset$"  $ =$. In other words, the definition symbol can serve as an equality sign. But the equality sign should not be used to stand for definitions/distinctness. I will probably start using the notation $f :=$, $f \equiv$, or $f: x \mapsto$ more frequently for defining functions. Thanks again
Answer: $y(x)\equiv f(x)$ if and only if $y$ is the name given to the dependent variable. In general, $f(x)$ could be named anything but $x$. Consider $z=f(x)$ which is a single variable function that is the $xz-$trace of a function $f(x, y)$. In this scenario, $y=f(x)$ is the trace in the $xy-$plane of the same two-variable function.
(Perhaps to be even more specific we'd have to call the traces something like $f$, $g$, and $h$ to avoid ambiguity.)
Answer: Basically they means the same thing, because $y$ is a variable which depend only by $x$.
Comment: Only in certain context. What is there to say about $y(t)$ or $y(\theta)$?
Answer: Actually, they are the same thing, however $y(x)=2x+4$ is more complete than $y=2x+4$ as a written statement because when you see $y(x)$, then you know $y$ being a function of $x$ before considering the right side.
Answer: It is an interesting question. I think they are the same. You may write $y=\cdots$ or $y(x)=\cdots$.
Actually, I think everyone will say that they are the same, and in fact I am wondering if someone answer to this question that they are not!
Answer: No, there's no difference. But you don't really see $y(x)$ all that much since it is commonly indicative when you say $y$ or $f(x)$ and then have $x$ in your equation on the Cartesian plane.
Although, I suppose if you don't want to confuse people, you can say $y(x)$ to indicate that it's solely on the $xy$ Cartesian plane and not the $yz$ or $xz$ Cartesian planes. But that would be repetitive if you say $y=2x+4$ and you can clearly see that there are only two variables.
The $f$ in $f(x)$ is just a notation (most, if not all the time) unless it is very clear that it's the $f$-axis, which is incredibly uncommon.


Ultrasonic sensor doesn't work inside case

Question: I have a very strange error. My ultrasonic sensor, when both speakers are sticking out of my case, doesn't work at all. It's a black case. It gives very "near" readings. But it does work when outside. Why could this be an issue?
Comment: Please add a picture of your setup.
Comment: Maybe you are getting leakage out the back of the transducer bouncing inside the enclosure.  You could try making a transducer cutout in a piece of comparable material so it is just a wall with no box.  Also try a box with the transducer end completely open, and a box filled with deadening material.  When you understand the cause you can engineer around it.
Answer: It is likely that the transducer and receiver are being coupled together by the enclosure, so that the signal being received first is the vibration through the enclosure rather than an external object. I would recommend enlarging the holes so they are not in physical contact with the enclosure.
You may also be getting similar problems if the board is secured very rigidly to the base of the enclosure, in that case maybe consider using some o-rings between the mounting hardware and the enclosure. But try step 1 first if the holes are tight fitting.
Comment: Yes, oh my this might be the case.
Answer: The sensor consists of a transmitter and a receiver, and it measures the time delay between a transmitted signal and the same signal being received. The further an obstacle which reflects the signal the higher the delay. If you put the sensor in a closed housing then the US signal will reflect back immediately when it bounces on the housing. It's normal that you get a "near" reading.
Always mount transmitter and receiver so that they have a free view towards the environment, So you need holes in the housing.
Comment: but the two speakers are sticking out of a hole


Mysterious Device on network, need some suggestions

Question: I just did a quick scan of my home network and I found this mysterious Intel desktop, looks like its an intel ethernet chipset but I just thought the name "QMDL" was sketchy and was wondering if anyone has ever seen something like this? I was wondering if it could be malicious or someone trying to look at my network traffic.
Comment: "desktop-xxxxxx" is the default hostname Windows 10 uses, so it could be a Windows 10 device. Not certain (anyone could just spoof that) but it's a clue.
Answer: There is only one way to know for sure that whether it is a rogue device - verify that it is a device you own or not. While you do that, consider the following scenarios.

Verify if it was a machine connected by the people who installed the router.
Verify if it is a VM running on one of your machines in bridged mode.
Verify if it is a mobile device like a surface tablet.

If the above three cases are invalid and the device isn't your own machines, it is likely to be rogue. If it is still online you can perform a port scan and see the results and try if you can fingerprint the same.
To make sure that it isn't snooping your network, use wireshark and see the packets from that particular IP and your router. If there are ARP responses which binds the rogue machine's MAC and your router's IP, there is a  man-in-the-middle attempt and you are being snooped.
Comment below if you need the specifics on how to perform any of these.
Comment: That was really helpful thanks man, I actually kind of freaked out and removed it from the network before i installed wireshark so I assume there is no way for me to go back and see whats going on. Also if this was a man in the middle attack would this guy have to be within a certain proximity of me to snoop? or could they be located anywhere in the world? I do have someone who was recently messing with me a few towns over and I know exactly who the kid is so that's why I'm wondering.
Comment: In this case, for an MITM, the device has to be inside the network
Comment: @user151357 he doesn't have to be next to you. If he got access to your network he can do his MiTM remotely.


Is it social engineering when you know you are being social engineered?

Question: More like a philosophical question.
Comment: I think what you mean to ask was "can it still be called 'trickery' if I know I am being tricked?". But "social engineering" is more than trickery.
Answer: Yes.
If you know you are being cheated, you are still being cheated. For social engineering, this may mean that you are warned, and that the attempt will probably fail. But social engineering in itself does not guarantee a positive outcome: a failed attempt is still social engineering.
Answer: Your question can be understood in different ways.
If the question is "Am I still social engineering someone if he knows he's being social engineered?", then I guess @Ljm Dullaart answer is what you're looking for.
Otherwise, if your question is "Could the fact that I know that I'm being social engineered be a way to social engineer the other person?" then absolutely yes: knowing that someone is lying to you is an advantage that, generally speaking, could let you gain additional information about the person you're talking with or the facts you want to know about.


How can I prevent my Desire HDs battery from draining overnight?

Question: I've recently got the new HTC Desire HD, which has a poor battery to start with (1230 mAh), but in the last two weeks I've had several nights waking up with a dead battery.
The first few nights, I suspect that wifi was still running and by default the radio didn't go to sleep when it's idle (changed that). I reduced syncing frequencies for most services to once a day, so that can hardly be the problem. When looking at the battery usage reports, it's mostly the huge screen draining the battery, but that's turned off at night. Last night I turned off any data connection and went to bed with 90% battery and woke up with a dead one.
So what on earth is crashing my battery so quickly? Does anyone have any suggestions other than the no-brainers mentioned here.
Comment: [Here's a very relevant discussion on XDA](http://forum.xda-developers.com/showthread.php?t=819266)
Comment: Did you fix the /init CPU hog bug? :)
Comment: I guess I could post the things I tried from the XDA forum, which indeed seemed to help.
Answer: I'm suggesting an app called PowerTutor (free on the Market). When you turn on the profiler, the app monitors the power usage of each applications and android subsystem, and give a detailed report of what application has been consuming the most battery.
The idea is, you turn the profiler on, then use the phone as usual. Be aware though, the power profiler itself is very power-hungry and it does not save the profiling result if the profiler is restarted, that means if your phone's battery runs out before you can look at the report, you'll just be wasting battery (IOW, you might need to wake up in the middle of the night to look at the report before your phone runs out of battery; or you might need to put the phone on charger, which might affect the result of the profiling since some applications might behave differently when charged and when on battery).
Answer: I ended up trying several things mentioned in the XDA-developer thread:

Changing the Networkmode from GSM / WCDMA Automatic to either GSM or WCDMA, XDA-users claimed that switching between these two modes is a huge battery drainer. In my experience this was the most important one.
Installing a widget, so I could check whether Bluetooth and GPS were really turned off. Especially GPS could run in the background, after using Google Navigation, without displaying the icon.
Turn off syncing for apps you don't really use or rate limit updates to a larger interval. You can always update manually and getting new contact info once a day is more than enough!
Remove widgets that need regular updates, even though the sync setting should have control this.
As I'm using a HTC Sense phone, I turned off all their proprietary apps, I simply don't trust the power usage of things like Footprints.

If you apply all these settings, you should manage to get a full days worth out of your battery, unless you play too much Angry Birds.
Answer: After trying out nearly every battery monitoring app I could find at the time, I ended up installing the free JuiceDefender and it's accompanying commercial licence JuiceDefender Ultimate. I found this was a good tool as it learned my usage habits, and would automatically turn the radios on or off depending on where I was or what I was doing with the phone. Combined with wiping the battery stats and a few recharging tricks, I managed to easily get a day of standby charge.
If you're game to load a custom ROM, you might be able to push the standby out to 2 days at the risk of bricking your phone if the flashing operation fails.
The only other thing that I didn't try is to see if there is a utility that can identify the many service apps running on the phone, and see if there is anything that might be turned off.  It's not unusual to have an OS running more services than are strictly necessary, even on a phone.


Free .net library to convert Word to PDF

Question: Is there any free .net library to convert word to pdf in asp.net for a C# application?
Answer: According to your question I think you can use Free.NET Word Library. It designed for developers to create, read, write, convert and print Word document files from any .NET platform. You can download it by using this link.


In Illustrator CS5 Scaling problems

Question: In Illustrator CS5 when I select Scale from the Transform menu it reverts to Free Transform and I have to select it again to get Scale. Anyone else have that problem?
Comment: Something I've noticed on Illustrator CS5 is the default transform on object > transform >scale **always** scales from the centre, even when a different point is selected on the 'reference point grid'. 'Transform Each' works alright though. Anyone else notice this?
Answer: "Scale" from the Transform menu is a sort of all-encompassing term; once selected it lets you proportionally scale, scale in one dimension, skew, distort, rotate etc. This is usually an easier solution for most users since it means they don't have to jump back and forth between "Scale", "Rotate", etc. in the tool palette.
The "scale" tool palette option lets you scale in one direction or proportionally. If it's easier, just select the object you want to scale and hit "s" on your keyboard for the scale tool. You'll now be using just the scale (in a "scale dimensions" context).
When using Free Transform, if you only want to scale just grab one of the handles and drag it up / down / left / right / whatever. To proportionally scale (i.e. height is adjusted as width is and vice versa) hold down the shift key while scaling.

In Illustrator CS5 Scaling problems


Can I use my computer while BitLocker is encrypting the system drive?

Question: I am thinking of encrypting my Windows 10 laptop with BitLocker (although I am curious about the answer for other versions too). If I start the process I imagine it will take a while since I have lots of data on my system drive. While this is happening will I be able to use my laptop still?
Comment: As said, yes. Except that when I encrypted my data drive (HDD), youtube videos did not play (only the first half second would show). Strange, as all browser files (program and profile folder) are on the (already encrypted) other SSD. Everything else worked fine.
Answer: Yes you can still continue to work while BitLocker encrypts in the background.
Comment: I experienced the same thing with TrueCrypt. The encryption system keeps track of which blocks are encrypted. Programs can continue operate as they normally would, regardless of whether that particular file has been encrypted or not yet (or partially encrypted).
Comment: Im encrypting a drive right now and using the computer
Comment: You can ever reboot and it will pick up where it left off.


GPIO extension - USB to GPIO module (NOT GPIO to USB)

Question: I ran out of GPIO on my RPI and now looking for a module to converts USB to GPIO for my Raspberry. I am not interested in converting GPIO to USB, but interested in USB to GPIO.
I've been googling for some time but haven't found anything like this. Do you maybe know if a product like this exists, that I can connect to my raspberry, and use some extra, additional GPIO ports?
Comment: https://uk.pi-supply.com/products/ryanteck-rtk-gpio-pc-gpio-interface or https://www.adafruit.com/product/2264
Answer: You can connect a Pi Zero via USB to your current Pi.  That will give you 26 additional GPIO.
https://gpiozero.readthedocs.io/en/stable/pi_zero_otg.html
Answer: You are extremely unlikely to find any such device.
Most of us would use a GPIO extender. There are several that work over I²C.


How to attach a list of fields to an entity

Question: I have a node, and I'm looking to attach a list of fields to it. The number of fields should be dynamic. I realize I can create a new content type, and use entity reference module to build a list of related nodes, but I feel like that's overkill. I really just need to attach simple list (or list of fields). Is there a way to do this? or am I misunderstaning
Comment: What kind of fields are you needing to use/add? Are they all going to be unique values, or used many times across different entities across your site? If you can paint the scenario a bit better I can probably help.
Comment: Yes, sorry,they may be repeated, but not very often, they are just text fields with a names.
Answer: There are a few possible solutions to what I believe you are asking:
Use a field collection.
http://drupal.org/project/field_collection
It allows you to create a field containing a few fields of information and attach those to a node. I think it is most likely what you are after.
A simple multi-value text field
The simplest option to attach a bunch of names to a node is just to set up a text field with unlimited values. Then you can add as many as you like. But I imagine that's simpler than what you need.
Taxonomy terms
If the values need to relate to each other across the site, use a term reference field with unlimited values and allow your users to create new terms on the fly when they don't exist already.
Content Type
If all of the names you need to add have additional data attached to them, you might need to go down the additional content type and node reference path you mention in your question.
I hope one of those ideas is what you after.


Date marked from Info-path forms into Calendar

Question: I have 4 info-path forms published in SharePoint online. Each form has date field in it.   I want that the SharePoint/outlook calendar, of the user (who filed the form), will be marked(as an event) against the date field from any of the form he/she filled up.
Comment: Can you expand the question a bit more with some detail, it's a little hard to understand what exactly you are looking for.
Comment: suppose user filled a form which has a date field (say: Next Payment Due On)        So, I want that date from Next Payment Due On  field to be marked as an event in that particular User's Outlook Calendar or SharePoint Calendar, when user submit the form .
Answer: Out of the box no.
Your non-programming way of a possible solution:

Create a task list to capture tasks
Create a workflow on the form library.  Promote the infopath date item to a SharePoint field and when the form is saved, have the workflow create a task in the task list.
Have users connect the task list to Outlook.

The other options available requires custom scripting or programming to reach the Exchange Web Services.


Can service dogs be kept indoors?

Question: Dogs are "haram" to be kept (except as hearding or guard dogs) and are not allowed in one's home.
But what about dogs trained to help disabled people(blind,hearing impairment,seizures......)?
They need to be close to their owner and living with them in order to be of help.
Could those dogs be kept indoors?
Sunni point of  view please but would like to know about others as well.
Answer: Generally, dogs should be avoided because their saliva is impure but trained dogs for helping disabled/blind  people are allowed because that is a necessity. However, they should be taught to not lick their owner.
This is the mainstream Sunni point of view.
Comment: Any source for the "saliva" is impure part? Its saliva similar to human saliva. I don't see the difference.
Comment: @masfenix The Saliva is impure but should be avoided is not Islamic, if you are willing to wash it, I have a similar answer here that explains it more: http://islam.stackexchange.com/a/24322/12537

Can service dogs be kept indoors?


Fish bent spine

Question: My black moor get sucking in my aquarium siphon durning water change. Is there any medicine or treatment to follow to straighten the fish's back/spine?
Comment: there is no treatment for this but it might heal on its own but this depends on the type of injury.
Comment: Ok so I put it In a hospital tank. It is still having a bent spine. Should I continue the hospital tank?
Comment: no reason to keep it in the hospital tank unless it has an infection or a wound that needs to heal.
Comment: Ok thanks for sharing the knowledge. Thats why I like stack exchange It helps people who are new to a hobby get their questions answered.
Answer: Similar symptoms might have very different causes. And the different causes lead to different treatments and different outcomes.
In your case, the best thing you can do is to allow the fish to live his life in the main aquarium - and prevent it from being sucked or harmed again :)
In my case, my Betta had a bent spine. I assume that it happened because the water temperature was quite low for some days - and he might have caught a cold or something. After the water temperature raised to normal levels, he slowly got his straight spine back.
Joke: both our fishes might have a benefit from some therapeutic massage, but it is unlikely that either of us will go to that length :)

Fish bent spine


Can I convert the brakes from rim to disc

Question: I have a 1990s vertik 2 it's the mountain bike one and I am wondering if I could convert the rim brakes to disc brakes if so what are good budget options
Comment: You can, if you really, really want to spend a lot of money for very poor results.
Answer: No.
You would require new wheel hubs with a disk rotor mount, and you would need a fork and a frame with caliper mounts.
Once you replace the fork, frame, and wheel hubs, its not economical.
Instead, shout yourself to some new rim brake pads.  Good kool-stop ones will improve your braking and it feels like a decent upgrade, for much cheaper.
Answer: There used to be an adapter kit made by Brake Therapy that would allow you to mount a rear caliper on a non-disk frame. It's the only adapter I've ever seen that looked reliable enough. I believe they're out of business though.
That would still leave your fork needing to be altered or replaced and replacing your wheels to be disk compatible. So no budget options really exist. Keep the bike as it is. Looks like a pretty decent bike from the era. Find something newer that already has disk capabilities. You should be able to find something used that's decent for under $200.


Feedback for On Hold questions

Question: My question https://earthscience.stackexchange.com/questions/383/what-evidence-is-there-of-an-anti-correlation-between-atlantic-basin-hurricanes remains on hold, despite it being modified in line with the feedback given and a request at the page for further feedback. It looks set to be closed soon. Given the lack of feedback to develop the question into a workable format, and lack of re-evaluation of the page following the suggested modifications, is there a point of putting pages on hold, rather than just closing them?
Answer: You need to realize that since we moved to Public beta we are very few to have close votes and reopen votes privileges. You need to let people some time to act on it.
As for your specific question, i think it's mostly a problem of legibility, i suggested an edit, to turn it into an actual question. I also voted to reopen as indeed it is now an answerable question and not just a quote as it was before.
Additionally "on hold" and "closed" are basically the same thing. "Deleted" is something else, that comes later, if indeed the question was unsalvageable, which was not.
Usually, when an edit is made to a question put "on hold", it should appear in the "Reopen" review queue, where people see the edit and can judge if it is sufficient to get reopen. I checked in my review history and didn't see your question in it. So I don't know what happened, if people decided to leave it closed before i saw it or if it didn't make it to the queue.
Otherwise, people who closed the question are not "pinged" when you edit or comment on the question, meaning we have to remember to check on it frequently if we want to give feedback.
Now if you think they should be a real, quickest feedback mechanism, you should bring the issue on Meta StackExchange as this is the proper place to suggest new features network-wide.
Comment: I guess now you just have to wait for the people in UTC-5 and further west to wake-up and join in since the post is still a few reopen votes short.
Comment: Thanks for the info. I think I did try and escalate it in the right way, waiting for a response to the edit (24h), request information in the post(48h) (perhaps this should have used @usernames in hindsight), I then contacted the help system (72h)(which I guess is not really operating, while there are no interim mods) then finally post here (96h).

Feedback for On Hold questions


Show an iPhone in Keynote

Question: I was wondering if anyone knew if you could, and if so how to show the iPhone in a Keynote presentation to demo software on it? Kinda like they do at the Apple Events?
Answer: You could use a jailbroken iPhone (please don't hit me!) and install a VNC server on it. You can now use a VNC client on your PC using USB or WiFi to show the iPhone screen!
Theres a little tool that lets to establish TCP connections to your iPhone through an USB port:

http://code.google.com/p/iphonetunnel-usbmuxconnectbyport/

I found these instructions:

Launch iPhone_tunnel, forward remote port 22 as local port 2022 (or 22 on Windows):
<code>./iPhone_tunnel
</code>
Connect in terminal:
<code>ssh root@localhost -p 2022
</code>

Replace port 22 with the VNC port, 5900. Also instead of SSH launch the VNC client :)
Comment: Sounds like quite a good idea actually. Might try that out for my next demo. My latest effort was to use the TVOutManager (https://github.com/robterrell/TVOutManager) and just switch to it by unplugging the video input to the projector from my laptop to my iDevice!
Answer: I'm assuming there is an easier way to do it, but if all else fails you could use the iPhone Simulator to help out. Depending on how detailed the presentation is you could probably even use screenshots of the simulator so you can throw them onto your slides.
Comment: Yea that was what I was thinking but I thought it might be more impressive to do it within the presentation like they do at the events... Can't find much online about it though!
Comment: I've put this as the answer as it's the best approach to the situation. Hopefully in the future Keynote might include this feature!
Answer: I suppose you could use the iPhone Simulator and Quicktime to record what you want to show on the Keynote, and then add the video to the slide (assuming you want to show the same actions every time you play the Keynote). Other than that, I would suggest exiting the Keynote and using the iPhone Simulator, then starting the Keynote again (inelegant but it works).
Answer: I've never used it, but this sounds like it might be just what you're looking for:
http://www.tuaw.com/2009/09/16/free-iphone-keynote-and-powerpoint-templates-help-get-you-from-t/
Here's the description frow www.TUAW.com:

Free iPhone Keynote and PowerPoint templates help get you from thought to finish
by Sang Tang (RSS feed) on Sep 16th 2009 at 9:00PM

Mockapp.com has created both Keynote and PowerPoint templates of iPhone UI elements, and has made them available as free downloads. Say you had a dream in the middle of the night about the most awesome iPhone app that, to your surprise, no one has thought of yet. Instead of waking up in a deep sweat and scribbling said ideas on paper, you could dream them up on Keynote.
After mapping out your concept on Keynote, you could then pitch it to others in a Keynote presentation. The Keynote and PowerPoint templates include alerts, the iPhone keyboard, arrow icons, buttons, as well as a host of other UI elements.
Answer: I realize this is very late but you should look into SimFinger.
https://github.com/atebits/SimFinger
I use it to simulate a real environment in the simulator (imagine that). I record the demo, and play it in keynote. This should hopefully solve the issue.

Show an iPhone in Keynote


Which rails server for development?

Question: Is there a "best" rails server to use for development (mongral, webrick, etc..)?  Or does it not really matter?
Answer: Short answer: develop on what you will deploy on.
Long answer: good Rails containers, like Unicorn, Thin, etc, really don't impact your development much but will impact production. And, each has just enough configuration related quirks that interact with your code and choice of gems that just diving in and working in that environment can save a lot of time, even if using continuous integration, but especially if not.
Answer: The "best" in my opinion is Passenger in conjunction with your choice of Apache or nginx, whichever you're familiar with. It's perhaps the only game in town when it comes to getting an application running quickly and reliably. The Phusion team has invested a lot of time and effort into building a complete package for a scalable deployment platform.
Mongrel is only designed to be part of your stack and requires a number of supporting pieces to work properly. It also has to be managed with a separate process launcher and that can be frustrating and can cause serious issues if done wrong. Mongrel2 is a better platform but will need some time to be properly assimilated by the Rails community.
Webrick was never intended as a production web server. It is only a toy server for testing. It is painfully slow and can only service one request at a time.
Answer: See my answer here Recommendations (and Differences) between different Ruby on Rails Production Web Servers

Which rails server for development?


How can I safely override contact form 7 styles?

Question: Where do I place css styles to override the default styles of contact form 7 so that my changes do not get overwritten whenever I update this plugin?
Comment: I changed some color styles in CF7 plugin's main stylesheet which works fine, but when CF7 is updated, I lose the changes made to the main stylesheet. Normally I would place these changes in my theme's main stylesheet, but CF7's stylesheet takes priority as it is loaded later in the cascade.

@weston - Can I add the styles in my theme's style.css (instead of CF7's stylesheet) and change the order that the stylesheets are loaded so that my theme's stylesheet supersedes all other stylesheets in the cascade?
Comment: We need more information. A link to your site or something showing specifically what you're trying to override would help.
Answer: Here are some ways to accomplish this.
If you are using a custom theme, you can edit that style.css and make the style changes that you want there.
If you are using a standard theme that you upgrade, you can make a child theme and then your stylesheet won't get overwritten.
You can create your own stylesheet and just link to it in the header.php in the theme you are using.
Answer: My site also uses contact form 7 with custom styles and bootstrap: http://splash.inting.org/wp/
Here are your options:
1) In building your form, enclose fields with other html elements (with relevant classes), like below:

    First Name*

        [text* FirstName id:FirstName class:input-xlarge]

You can also define IDs and Classes for your contact-form 7 elements like above.
2) Create a custom.css file and update your current theme's header.php, ensuring that the stylesheet is added last (right before closing the header). If it's added last, it is less likely that it will be overwritten by the theme or plugin styles.
3) Use !important on css class and id definitions so they don't get overwritten by other styles
Answer: What I've done is to just prevent the plugin's bundled stylesheet from loading. This is documented on http://contactform7.com/controlling-behavior-by-setting-constants/ and looks like this:
/* Settings for Contact Form 7 */
define('WPCF7_LOAD_CSS', false);

This snippet goes in the wp.config file.
Doing this results in a form without any special styling. This may seem like extra work but actually better suits integration into an existing theme, since the layout and appearance of the form can be fully controlled.
As an example, my styles for the contact form looks like this:
.wpcf7-form { margin-top: 1em; }
.wpcf7-form fieldset p { margin: 0; }
.wpcf7-form label { display: block; float: left; clear: left; width: 150px; text-align: right; margin-right: 5px; margin-bottom: 1.5em; }
.wpcf7-form input[type="text"], .wpcf7-form textarea { display: block; float: left; width: 250px; margin-top: 0; }
.wpcf7-form textarea { width: 450px; }
.wpcf7-form fieldset.submit { margin-top: 1em; position: relative; }
.wpcf7-form input[type="submit"] { display: block; margin-left: 154px; width: 150px; }

.wpcf7-display-none { display: none; }
.wpcf7-response-output { margin: 0 155px; border: 1px solid #000; padding: 0.5em; top: -1em; position: relative; }
.wpcf7-mail-sent-ok { border-color: #398f14; }
.wpcf7-mail-sent-ng { border-color: #ff0000; }
.wpcf7-spam-blocked { border-color: #ffa500; }
.wpcf7-validation-errors { border-color: #f7e700; }
.wpcf7 img.ajax-loader { margin: 1em 0 0 155px; }

span.wpcf7-form-control-wrap { position: relative; float: left; }
span.wpcf7-not-valid-tip { position: absolute; top: 20%; left: 20%; z-index: 100; background: #fff; border: 1px solid #ff0000; font-size: 0.9em; padding: 0.2em; }
span.wpcf7-not-valid-tip-no-ajax { color: #f00; font-size: 10pt; display: block; }

The .wpcf7- bit is the important one, as styles can be scoped to just forms produced by this plugin.
Answer: These is a common misconception that the Contact Form 7 (CF7) plugin controls the appearance of CF7 forms though the plugins CSS style sheets. In truth the Contact Form 7 plugin uses only very minimal CSS styling to allow CF7 forms to blend in with most websites.
The actual look of CF7 forms on your website will depend largely on the current WordPress theme used and the CSS styling that theme applies to standard HTML form elements. To change the appearance of your CF7 forms to suit your requirements, you will need to adjust the CSS used by your current theme for these HTML form elements.
Use a Child Theme to make changes to your CF7 forms CSS
The most common and preferred method to makes changes to CF7 form styling is to create a Child Theme. Make any necessary additions in the child themes style.css, rather than directly in the themes styles.css. That way you don't loose your changes when you update the theme.
The style.css file of the child theme usually imports all styling from the parent theme by including the following CSS code at the top of the child theme's style.css file.
/* Import Parent Theme */
@import url('../parent-theme/style.css');

Any CSS changes you need to alter the appearance of our CF7 forms are added below this. Due to the CSS loading heirachy, any CSS changes made here will generally overwrite styles previously set in the parent theme.


What is authenticity of this forum?

Question: I am an active member of stackoverflow and some other programmers related communities here. And they all are very good and working great. They are like must have for IT professionals.
But coming to religious matters, how is it good to let all kind of people answer the questions which must be answered by proper muftis, when we don't know the person answering is even a Muslim?? Or he is trying to inject some wrong beliefs in Islam? A person without any proper knowledge cannot give fatawa. So, how is this forum authentic and how is it not going to be disastrous as some people like me might give wrong opinions(which they thing are true) as they are not muftis and they are not supposed to give such statements and tell what Islam says about something when they don't have knowledge of it? And as lack of muftis here and no mechanism for answers to be checked by muftis, how can someone trust my answer?
A solution might be to have authenticated muftis on site, or a privilege like moderators a new privilege of MUFTI which will be awarded to only those who are actually mufti and they are able to prove it. They can mark any answer as approved by mufti, or their answers will be marked indicating they are mufti and their answers are more authentic.
Or anything like that to counter the fear i mentioned above.
Answer: We are not, nor have we ever been, a fatwa site.
If a question truly "must be answered by proper muftis" then it's important that it either be closed, downvoted into oblivion, or edited so that it can work here. We don't check credentials at the door, nor do we filter scholarly answers from non-scholars; given how against the Stack Exchange philosophy it is, this is also unlikely to change any time soon.
The fact that so many questions here aren't curated thus just indicates that the community at large still feels that these are perfectly acceptable questions to ask random strangers on the Internet (an opinion which I do not share).
If you want to encourage users who actually know what they're talking about, it's important to vote properly; if you feel that an answer as-written is just not useful coming from a random stranger on the street, downvote it. If an answer as-written is well-written, well-referenced and informative, and which would be just as useful coming from Shaykh Muhammad Saalih al-Munajjid as it would from Joe Six-Pack in Milwaukee, then vote it up.
But if people insist on voting for posts that do nothing more than copy the first link they pulled from Google and/or from their fatwa site of choice (something which literally anybody can do), then that's what you're going to get: A site full of non-experts cribbing other people's work. The community reaps what it sows.
The voting mechanism is foundational to the Stack Exchange model; that's no different here than on any other Stack Exchange site. When applied properly, it does exactly what you're asking for here: It lets people trust your answer, because it was reviewed by and met the standards of the expert community. But if you build a site of non-experts, for non-experts, you're just going to end up with a bunch of answers that, as you fear, aren't (and probably shouldn't be) trusted by anyone.
Comment: @ZiaUlRehmanMughal If you'd bothered to read through meta (including but hardly limited to the links I just posted), you'd see that almost all those exact same arguments have already been made. The whole point of this site is to gather an expert community who are willing and able to figure out *how* to make Stack Exchange work for Islam (Christianity and Judaism have figured it out), but pretty much all anybody does is complain that it *doesn't* work rather than put any effort to *making* it work.
Comment: Actually this forum CANNOT work like other stack exchange sites. Because like in stackoverflow i post a problem "Hay this is not working in my code where is the mistake." And someone points it out, you fix it, test if it works and thats all you care about.
Comment: But when it comes to islam you cannot test whether or not the answer IS what islam says about it. And about posting links to the Fatwa sites online, i think thats better than people like you and me giving their own fatwa's which they are not supposed to.
Comment: FATWA means nothing but someone's opinion.
Comment: Even on stackoverflow we get answers like "This will help:" and only stating some links to other sites having good explanation of the problems and there's no issue there in that. Infact if it solves the problem, those answers get high upvotes and acceptance in that community. But here(as of my experience) if someone try not to give his own opinion rather find and link to some proper fatwa, than that answer is either downvoted or is deleted. That's really the problem here.
Comment: @ZiaUlRehmanMughal If you think a question needs to be answered by a mufti, and you answer the question even though you are *not* a mufti (rather than leaving it to be answered by someone who is actually *qualified* to answer it), then why *shouldn't* you be downvoted? That sounds like working-as-intended to me.
Comment: The whole point is that there is no way to get to know who is mufti and who is not, and which point of view is correct and which is not. That's exactly why we rely on mufti's. And if i link to a proper fatwa somewhere, why do i still get down vote? Aren't we supposed to take fatwa's from muftis? And if i have given a ref to a fatwa addressing that answer why i am getting down vote?
Comment: And i WANT this forum to work, this is not that i am only playing blame game here just because i got some down votes. This can be a great forum for whole world to know about islam. But for that to work we cannot rely on same rules as of programming or some other communities like that.

What is authenticity of this forum?


Icing Made with Yogurt powder

Question: I am looking into making icing using yogurt powder. My question is, would it still need to be refrigerated after I make it. The ingredients in the product I am look at are nonfat milk solids, whey solids, lactic acid.
Answer: It will absolutely need refrigeration. The reason why the powder is shelf-stable is that it is dehydrated and lacks the water bacteria need to survive. Pretty much everything you could mix it with to make an icing will contain water, meaning that it is no longer shelf stable.
Even if you were to mix it with something without water, e.g. shortening, the strict food safety answer is that it still needs refrigeration until somebody has ran the necessary microbiological tests to prove that it doesn't.

Icing Made with Yogurt powder


Were there any interstellar probes prior to the opening of the gates?

Question: We know that the Mormons intend to take the Nauvoo to another star, so at least the idea of interstellar travel was in the books. I'm wondering if there are any references to interstellar probes actually sending data back from another star system in the books or stories. The key is that I'm interested in missions before the gates opened, since I know that at that point interstellar probes and more are a reality.
Answer: There were no Earth-sent interstellar probes prior to the gates opening ever mentioned. The books and TV series were pretty consistently predicated on hard science (other than the Epstein Drive and the advanced alien tech). The Nauvoo, even with Epstein Drive, was going to take hundreds of years to reach its destination star. They were 'going on faith'.

since I know that at that point interstellar probes and more are a
reality

No, I do not believe Earth based interstellar probes were an in-universe reality.
Semantics of "interstellar" come into play here. Do we count simply beyond the bubble of our sun's heliosphere or do we count something only when it is a meaningful distance nearer to a star not our sun. A few months ago I made some simple calculations about Voyager distance beyond heliosphere into "interstellar space" relative to the distance to Proxima Centauri. In a comparison to a coast to coast trip across North America, Voyagers are about 1/2 a block from front doorstep.
Comment: @Lexible hmmmm. It is quite literally in the OP question. "I'm wondering if there are any references to interstellar probes actually sending data back from another star system in the books or stories."
Comment: @Lexible well, OK... if you perhaps include sending probes into the vast interstellar void. However- actually getting to another star and sending back information to Earth... NO.
Comment: I mean, [we were sending interstellar probes out-of-universe in the 70s](https://en.wikipedia.org/wiki/List_of_artificial_objects_leaving_the_Solar_System).
Comment: +1 Whoops! Don't know how I blipped over that! :) Carry on!
Comment: Correct I meant a probe actually arriving at another star system. Also for the "at that point" I meant "once the gates opened". We have lots of discussion about probes being sent through the gates in the last three books but I was interested in the pre-gate timeline


Fractional Laplacian of $(a-x)_+^\alpha$ in $(0,1)$

Question: How can I compute the spectral fractional Laplacian of $(a-x)_+^\alpha$ on $\Omega = (0,1)$?
Here the operator is defined as  $$(-\Delta)^s u = c_{N,s} \int_0^\infty (e^{t\Delta_N}u(x) - u(x)) t^{-1 - s} dt ,$$ where $e^{t\Delta_N}u$ is the solution of the heat equation with homogeneous Neumann boundary conditions on  $\Omega$.
Comment: I would be surprised if a nice closed-form expression existed. A natural approach would be to expand $(a-x)_+^\alpha$ in the Fourier cosine series $\sum a_n \cos(n \pi x)$ and use the fact that $(-\Delta_N)^s [\cos(n \pi x)] = (n \pi)^{2s} \cos(n \pi x)$. I do not know if there is a simple expression for $a_n$, though.
Comment: Right hand integral looks like an operator with respect to $t$: $\int^\infty_0(u(x,t)-u(x,0))t^{-1-s}dt$ with parameter $x$.
Answer: The operator $(-∆)^s$ is the Fourier multiplier $\vert\xi\vert^{2s}$ and thus deserves to be denoted by $\vert D\vert^{2s}$. Now the distribution $u_\alpha(x)=x_+^\alpha$ is homogeneous with degree $\alpha$ and thus has a Fourier transform homogeneous with degree $-1-\alpha$. We have in fact
$$
\hat{u}_\alpha(\xi)=c_\alpha (\xi-i0)^{-1-\alpha}.
$$
You are interested in $v_\alpha(x)=u_\alpha(x-t)$ so that
$$
\vert\xi\vert^{2s}\hat{v}_\alpha(\xi)=e^{-it \xi}c_\alpha (\xi-i0)^{-1-\alpha}\vert\xi\vert^{2s},
$$
and
$
(\vert D\vert^{2s} v_\alpha)(x)=\int e^{i(x-t) \xi}c'_\alpha (\xi-i0)^{-1-\alpha}\vert\xi\vert^{2s}d\xi
=(\vert D\vert^{2s} u_\alpha)(x-t).
$
Translations commute with derivations, including fractional versions.
Comment: I think Jay is asking about a different operator: the fractional power of the Neumann Laplacian on $(0,1)$.
Answer: Let us denote the corresponding eigensystem $\{\lambda_n,\phi_n\}$.
If $u(x)=\sum\limits_nu_n\phi_n(x)$, then we have
$u(x,t)=\sum\limits_n\exp(-\lambda_n t)u_n\phi_n(x)$. Since
$\int\limits^\infty_0(\exp(-\lambda_n
t)-1)t^{-1-s}=-\lambda^s_n\frac{\Gamma(1-s)}{s}$ we obtain
$$
\text{R.H.I.}=-C_{s,N}\frac{\Gamma(1-s)}{s}\sum\limits_n\lambda^s_nu_n\phi_n(x)$$


Is there angular momentum conservation in models like the Ising model?

Question: In Quantum Mechanics conservation laws are fundamental, I was thinking about spin altering models of interaction such as the Ising Model and realized that it isn't at all clear how angular momentum conservation occurs in such a situation. If there is spin flipping occurring where does the contrary compensating angular momentum go as to have global angular momentum conservation? The interaction fields absorb this angular momentum?
Comment: There is nothing fundamental about conservation laws in either classical mechanics or quantum mechanics. A simple rigid wall does, for instance, not conserve momentum. Neither does the Kepler problem with a fixed center mass conserve momentum. In QM none of the potentials where V(x) is a function of just one coordinate is momentum conserving and a system with magnetic field does not conserve angular momentum. WE have to chose potential functions that are. Sometimes we do and sometimes we don't. It's a choice and we have to be aware of its consequences.
Comment: @FlatterMann you should write this as answer, so it does not disappear!
Comment: @hyportnex It doesn't really answer the question about the Ising spin model, though. It's just a general remark why having non-conservative models is a perfectly fine approximation in appropriate situations (nobody is going to complain about the planet speeding up or slowing down a bit just because a kid bounces a ball of a wall). The two answers given, so far, are addressing the concerns of the OP much better and I really don't know enough about the Ising spin model to give an appropriate answer. Thanks for the support, though.
Comment: Although only tangentially related to your question, note that one can (and one does!) study the Ising model in a fixed-magnetization ensemble. (It is actually quite a natural thing to do in the lattice gas interpretation of the model, since it then corresponds to a canonical constraint.)
Answer: It is the bath degrees of freedoms which absorb or provide the compensating forces.
It depends on the ensemble you are using:

Microcanonical Ensemble: The number of + spin and number of - spin is conserved since energy is conserved.

Canonical Ensemble: The system in question can exchange energy and spin with a bath at temperature T. So No conservation.

Grand Canonical Ensemble: No conservation.

in 2 and 3, it is the bath degrees of freedoms which absorb or provide the compensating forces.
But all three will agree in relations between average quantities as the fluctuations die down as some power of N(Number of Particles).
Comment: Regarding 1., note that fixing the energy does not fix the magnetization (think of a 2d grid with one spin having two + neighbors and two - neighbors, for instance; in this case, you can flip the spin at 0 energetic cost).
Comment: Yeah, true. Energy conservation leads to number conservation only with some magnetic field bias.
Answer: Angular momentum is conserved, but sometimes that isn't the important thing. An Ising model might be used to study magnetic properties of a solid, or phase transitions. Details of how angular momentum is conserved are not the primary interest, and don't have a large effect on these properties.
If spins flip and primarily align in one direction, a tiny rotation of the solid can make angular momentum be conserved.
Sometimes a benefit of a model is that it ignores things that are not of immediate interest. This simplifies calculations, and makes more processor time available for the things that do matter.
Answer: The Hamiltonian of the Ising model is usually assumed to be
$$H=-J\sum_{i,j} s_is_j$$
There is no momentum in this expression and no kinetic energy! In Statistical physics, it is common that you can integrate part of the partition function. Think to the ideal gas:
$$\eqalign{
{\cal Z}&=\int e^{-\beta\sum_i[{p_i^2\over 2m}+V(\vec r_i)]}d^{3N}\vec p d^{3N}\vec r\cr
&=(2\pi mk_BT)^{3N/2} \int e^{-\beta\sum_iV(\vec r_i)}d^{3N}\vec r
}$$
The same has been done with the Ising model. Indeed, the partition function of the Ising model is usually written as
$${\cal Z}=\sum_{\{s_i=\pm 1\}} e^{-\beta H}$$
One can notice that there is no integration (or summation) over the momentum of the spins. It is because this integration has already been performed, as in the above example of the ideal gas! What is known as the Ising Hamiltonian is actually not an Hamiltonian but only the potential energy. There is no kinetic energy anymore. Therefore, it is not possible to derive conservation laws for momentum or angular momentum.
Comment: In the continuum (scaling) limit, where the ising model approaches a scalar field theory, can't you write down momentum operators?


Palindromes and linear grammars

Question: Given a linear grammar G, is it possible to determine if L(G) contains a palindrome?
Comment: What do you think?  What have you tried?  What research have you done?  We normally expect you to do some research on your own before asking and to show what you've tried in the question.
Answer: Consider Post correspondence problem (PCP). If $\alpha_1 \dots \alpha_n$ and $\beta_1 \dots \beta_n$ are the words of PCP, then $S \to \alpha_iS\beta_i^r$ and $S \to \#$ where $\#$ is a symbol not in any of $\alpha_i, \beta_i$ and $s^r$ is the string $s$ reversed, gives a grammar $G$ such that if $G$ generates a palindrome, then the corresponding instance of PCP has a solution. PCP is RE though.
Comment: You prove it is at best RE. You should add the procedure to actually do it.

Palindromes and linear grammars


Upload file in Android webview

Question: I have a html form like this
<form data-ajax="false" action='UserPhoto.php' class="settings" method='POST' enctype='multipart/form-data' >
<input type='file' style="height:25px" name='photo' />
<input type='hidden' name='task' value='upload'>
<input type='hidden' name='file_size' value='5000000'>

and I want to upload it by using webView posturl function, is it possible?
as I know posturl can send String data by this way
String value1 = "persistent=1";
String value2 = "&email="+ 2nd_value;
String value3 = "&password="+ 3rd_value;
String postData = value1+value2+value3;
webView.postUrl("http://www.abc.php",EncodingUtils.getBytes(postData, "BASE64"));

but is it possible for me to post .png together with some string values?
and I know another method using this way to upload photo
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("ENCTYPE", "multipart/form-data");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
conn.setRequestProperty("photo", fileName);

but this way doesn't communicate with webview, I need to post the photo using webview as user session is kept with it.
Thanks for helping.
Answer: If you use webview only to upload image to the server you'd better use somethings like this http://loopj.com/android-async-http/ . It is easier and faster.

Upload file in Android webview


Deep linking from another app isn't working for Amazon prime and disney+hotstar

Question: It's not possible to send data to amazon prime and disney+hotstar. I was trying to send user to amazon prime when they click a (video) link (e.g. https://www.amazon.com/gp/video/detail/B01MSPI8JN/ref=atv_dp_share_cu_r). I thought it was Amazon prime which doesn't support it. Then I downloaded Amazon shopping and noticed I can successfully send data to Amazon shopping but not Amazon prime neither disney+hotstar app (using a video link of disney+hotstar's). I was reading the this and this but, they weren't helpful.
I have made sure that I have downloaded Amazon prime as well as disney application.
<code>Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse(https://www.amazon.com/gp/video/detail/B01MSPI8JN/ref=atv_dp_share_cu_r));
startActivity(Intent.createChooser(intent,null));
</code>
I thought it doesn't work for this link only. But I have tested others also. If you wonder if it works for any other application then I will say that It worked perfectly for netflix, zee5 and many more. If you also wonder why I used Intent.createChooser then I will say that I wanted user to select which app they would like to use to open the link (unfortunately it's useless cause it only opens default web browser).
FYI, I have also tested amzn://video/detail/B01MSPI8JN/ref=atv_dp_share_cu_r instead web URL. But still doesn't work.
If you think it doesn't work cause they didn't implement it , then I will say that I have used reversed engineering to view their manifest and confirmed that they have implemented deep linking (Amazon prime, and Disney even Hotstar). There's another easier way to see, what they actually support if you have Android 11 (I have just figured it out now). Go to app info-> Open by default->Supported links
Comment: [Cross-posted](https://software.codidact.com/posts/287382)
Answer: There's actually a reason I asked the question. There's some similar (very few) questions available in SO but none was answered ever (there's few answers also but they are completely useless in 2022, perhaps worked perfectly back then)
Solution : Choose link correctly. Amazon prime can't access amazon.com/....... but they can access only https://app.primevideo.com/detail?.....
the question is how to find those links? Follow the following steps :

Visit Amazon Prime
Select a movie/series
Click on share button.
Click on copy URL (which appears after clicking on the share button).

The URL is available in your clipboard is the correct link. (I can't really test for Disney or hotstar cause they are unavailable in my country also, VPN doesn't help at all, I don't know why. In question, I added cause my client tested it didn't work for him).

The short answer : link.
The medium answer : All the problems available are behind the link. Looking at which link send to those apps was useless cause when I looked at those URL, (giving example of Amazon prime) Prime video says supported links are :

amazon.de
app.primevideo.com
watch.amazon.de
amazon.co.jp
amazon.co.uk
watch.amazon.co.jp
watch.amazon.co.jp
amazon.com
watch.amazon.com.

For me, only app.primevideo.com worked. Others were useless. I don't know why (According to code they should work but in reality something else happened).
Comment: Hi @Billy Istiak, the same issue facing with disney+hotstar also can please provide any solution if knew it.


Cannot boot into ubuntu after installing it on to hard drive

Question: I was prompted to reboot after finishing the installing of ubuntu kylin(i have same problem with regular ubuntu) I either boot right into windows or if I remove the usb, I boot from the usb again which is not helpful. I can see that I have them installed as 3 partitions (bios grub(1Mb), ext4, swap) but i can't find a way to boot it. I have done some searching and someone said the grub is installed right on the usb from a live usb install, but I can see the grub in my partitions.
Answer: You have to try boot-repair after getting into your flavor of Linux
From terminal(Ctrl+T)
<code>sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
</code>


How to make an existing AppleScript file to work as a service?

Question: I made an AppleScript, saved it as a file in a specific folder on my hard drive. Now I want to assign a shortcut to it and looks like I have to make a Service via Automator, but the Run AppleScript asks me to put the code inside, while I want to execute the already existing .scpt file. How to do that?
Answer: Yes, Automator is the best option here. To create the service follow these steps:

Open Automator and select Service:

Search 'applescript' and drag the action to the right pane:

Change Service receives selected text to Service receives no input so that it always appears in the Services menu:

Replace (* Your script goes here *) with:
do shell script "/usr/bin/osascript /path/to/your/script.scpt"

if you wish to execute your existing .scpt file. Note that osascript can't handle user interaction like displaying a dialog window:

To overcome this limitation either use this workaround or simply replace (* Your script goes here *) with the contents of your script.
Save it:

If you wish, you can assign a shortcut to your new service. Select Services>Services Preferences in Finder (or any open application):

Assign a not so common shorcut:

Now your service is accessible from any application through the shortcut you assigned in the previous step:

If you ever want to get rid of the service open ~/Library/Services, delete the service and empty the trash:
Comment: @Zack Thanks, I don't know why `osascript` needs 4 additional seconds to execute your script, but Automator is not the cause of the delay, which was my concern. You may want to debug `osascript`, see https://opensourcehacker.com/2011/12/02/osx-strace-equivalent-dtruss-seeing-inside-applications-what-they-do-and-why-they-hang/ and https://stackoverflow.com/questions/31045575/how-to-trace-system-calls-of-a-program-in-mac-os-x
Comment: I said I want to execute existing script file, not to write it again into Automator.
Comment: I thought that copy/paste would be OK, but yes, you're right, it's stated clearly in your question. Use `osascript`, as explained in other answers.
Comment: @Nakilon I've added how to use `osascript` in Automator to run your `.scpt` file, a limitation and two workarounds.
Comment: I just did this.  It worked; but, it now takes 4 to 5 seconds to launch the script.  (When the code was saved directly in the workflow, it launched almost immediately.)  Any idea what causes this, or how make it launch faster?
Comment: @Zack When you run `/usr/bin/osascript /path/to/your/script.scpt` in a Terminal window, does the script also need 4 to 5 seconds to launch?
Comment: I'm not sure.  That particular script requires a selected email message.  I'm not sure how to fake that from the command line.
Comment: @Zack Launch Terminal and type `sleep 10 && /usr/bin/osascript /path/to/your/script.scpt`. This gives you 10 secs to switch to Mail and select the message before the script runs. Could you try it and report back?
Comment: Yes.  If I select a mail message, then run the script from the command line, it takes 6 seconds before the dialog box pops up.  When the code is saved directly in the Automator script, the dialog pops up less than 2 seconds after selecting the script from the services menu
Answer: In the script, add an on run argument:
on run
    -- do whatever the script does
end run

Then you can use the Automator "Run Shell Script" action, with the osascript command:
osascript /path/to/script.scpt

osascript is a command which executes AppleScript in the shell. You need the lines in the script to allow the script to be executed outside AppleScript editor.
Comment: You don't need to include an explicit run handler. All scripts have an implicit run handler. The reason why Automator's Run AppleScript action includes an explicit run handler might be because Automator uses the special `on run {input, arguments}` form, but even in Automator you can just remove the run handler.
Comment: @ I'm wondering if this ping gets to you. Kudos on the creative name selection.
Answer: Perhaps you'd want to take a look at This Service, which allows you to "create Mac OS X services from any script."
Comment: Can you provide an answer here rather than just a link
Answer: I wouldn't recommend creating Automator services to assign shortcuts to scripts. There is a bug in in 10.7 and 10.8 where the keyboard shortcuts for Automator services don't always work until you hover over the services menu from the menu bar. There is also a relatively long (maybe 0.1 to 1 s) delay before services are run.
See this answer for other ways to assign keyboard shortcuts to scripts. I use FastScripts and Alfred myself.
Comment: I'm not sure if it affects all OS X installations or all services, but I've ran into it multiple times on different installations, and it has mentioned by other people here and at Super User. Occasionally the keyboard shortcuts for all Automator services stop working (or nothing happens if you press them), but they start working again if you hover over the services menu from the menu bar, or if you for example select one service with the mouse.
Comment: I  have never experienced this need to hover? do you have more details of what you are talking about
Answer: You can RUN the existing script with a simple automator service like this.
And assign your shortcut from within the keyboard short cuts as normal.
Just remember some applications may need to be relaunched before they pick the shortcuts up.
example.
sayHello script:
say "hello"

Automator service:

Which in this example uses:

No input
Any application.

The Action is a Run Shell Script
The code just uses the unix command osascript and the path to the file.
Pass input can be to stdn or to argument
Thats it nothing special needs to be done to the script.
For further details on the osascript command look at the man pages for it. The man page give another example where you can pass arguments to the script.
Answer: To develop a Service, you need some sort of software which will create a Service such as one of the following:

Automator to  create a .workflow
ThisService to create a .service
Xcode to create an .app

All of the above kinds of services are packages.  They are all folders which contain an plist that specifies the attributes of a Service.
Here is how I created a Service using Automator that uses a "Run AppleScript" Automator action to call an existing .script.


Get back to grub menu without reboot

Question: I have two separate Linux installations on my system which I can access from grub. Is there a way to get back to the grub menu to access the other system without having to reboot?
Answer: No, there's not.  Once you're booted, there's no way to transfer control to GRUB.
Instead, you can look at User-Mode Linux and regular virtualization (VirtualBox, Xen, etc.).
Answer: No. When grub boots the OS, grub is no more and you can't go back to grub from the OS as it's no longer running. Grub is not just another application, it can only be run at boot time of the computer.

Get back to grub menu without reboot


Models colors are not visible just an outline

Question: I downloaded a blender model and opened it in blender. There are no colours. I need to see the fully colored model so I can import it into pshop. Any help would be appreciated.
Comment: The pink color indicates that the texture is missing, this is why you cannot see the colors on the model. Either you have to go into the material shader and there probably is an image texture node where you manually ahve to add the image texture which might you might have somewhere separately in the download folder, or the texture is missing because it wasn't contained in the download.
Comment: Oh - I just read this too. Excellent - you are right. Thanks. You appeard as a comment.
Comment: Yes, I appeared as a comment because I commented on it  :)
Answer: Whenever blender shows a model in pink color, it means the texture file or an image is missing from that model. Also, sometimes blender fails to link the a texture file.
You can go to File > External data > Find missing files and browse for the location to recover them.
For detail instructions on how to link a texture or image file you may refer to this thread How to re-link missing blender files
Comment: Thank you so much Rose.


Origin of wearing a hat

Question: Wearing a hat has become so widespread in the orthodox community but what is it's origin? Is it based off of anything from the Torah or Chazal? How old is the custom to wear a hat? And when did it become so widespread?
Comment: Are you asking about wearing a hat for prayer, or wearing a hat in general?
Comment: Prayer & Shabbos
Comment: Kabbalistically, the hat represents Keter - a level above the head, which completes the 10 "Sefirot" and makes a person "complete". This perception is different from simply covering the head with a piece of cloth, but requires a headgear.
Answer: This is actually a very complicated question. I will begin by discussing any religious or Torah requirements regarding a head covering, then talk about hats and their relationship to Jews.
There is no religious origin to wear a "hat." By all accounts wearing a hat is a non Jewish custom. The closest thing to an official Torah based Jewish head covering is a Sudra, which is some sort of turban like head covering. The Talmud says If one wants to cover his head one should wear a head covering that wraps around the head such as a turban and say the blessing "Blessed are you Lord our God who crowns Israel with splendor."

כי פריס סודרא על רישיה לימא ברוך עוטר ישראל בתפארה
When he spreads a sudra over his head he should say: 'Blessed is He who crowns Israel with glory'

Brachot 60b, Talmud Standard Vilna edition
Non Jews in Europe did not wear anything resembling a turban and apparently neither did Jews so we start seeing written accounts by 13th century Ashkenazi Jews that the blessing was no longer being said.

A) R. Asher ben Shaul of Narbonne (13th century France) in his Sefer haMinhagot (pg. 141) [15] recorded that the blessing was not cited in his region:
ומי שעוטר מצנפת כמו שעושין בספרד מברך עוטר ישראל בתפארה שדומה לעטרת, והזכיר ישראל מפני שכינה שהיא שורה עליהם, ולא יתכן שילכו בגלוי ראש ועל כן קשר להם כתרים בסיני לכל אחד, וכן אמרו בתלמוד (קידושין לא א) שכינה למעלה מראשי, ולא כן הגוים. מכל מקום (הוא) משמע שאע"פ שאין אנו מתעטרין במצנפת אנו מתעטרין בכובעין דין הוא שנברך עוטר ישראל אלא שאין מנהגנו לומר כן, ונראה בעיני שהמנהג שלנו שאין אנו מברכין משום דאין כל ישראל מכסין ראשיהם והולכין בגילוי הראש.
Asher recognized that עוטר ישראל בתפארה was an appropriate blessing for the turban because "it resembles a crown" (דומה לעטרת).

We see similar accounts in the 14th century.

B) R. David Abudirham, a resident of 14th century Christian Spain, in his enumeration of the morning blessings in Sefer Abudirham [16] (1339) skips any version of the head-covering blessing. In a later chapter he wrote [17]:
ועוד מוסיף בגמ' כשמניח סדינו על ראשו מברך עוטר ישראל בתפארה על שם (שם קג, ד) המעטרכי חסד ורחמים ועל שם (ישעיה מט, ג) ישראל אשר בך אתפאר. והטעם לברכה זו לפי שהיו עוטרים מצנפת כדי שלא ילכו בגלוי הראש. ואמר כאן ישראל לפי שהשכינה שורה עליהם ולא על הגוים. ובכל ארץ ישמעאל נוהגין לאומרה מפני שהם מניחים מצנפת על ראשם, אבל באלו הארצות אין נוהגין לאמרה כי אינם מניחין מצנפת. אבל נוהגין לומר ברכה אחרת שאינה נזכרת בגמרא …
The intention of Abudirham appears to be that in Christian Spain ("these lands") the turban was not worn by Jews and therefore no headdress blessing was said, unlike in North Africa and the Levant [18].

Source: https://www.uncensoredjudaism.com/en/archives/1857
While these sources don't conclusively prove when Jews started wearing a hat in Europe, it does say that the European Jewish community had broken with traditional Jewish dress and had actually removed a Talmudic blessing from their religious practice. The sources above indicate that many Jews didn't wear a headcovering at all (not even a kippah!). It therefore makes sense that the blessing would not be re-instituted for "the hat" that is now in common use since the hat was clearly a later use of a gentile article of clothing.
It should be noted that now almost no Jewish communities say this blessing when putting on a head covering. This and all the other dressing related blessings have been relegated to a fixed part of the "morning" service and are now said in synagogues, completely separated from the acts they were tied to in Talmudic times. I have only seen certain Rambam based groups who continue the proper practice of saying this blessing with a turban style head covering.

Jews in Europe (and other parts of the world) were often forced to wear clothes that distinguished them from non Jews. This way Christians and Muslims would be able to tell who was and wasn't a Jew based on their style of clothes. There were many styles of hats that Jews in Europe were forced to wear that were different based on location or time, but many times these articles of clothe were meant to embarrass or humiliate the Jews on top of setting them apart. Here is an example from the 14th Century. Here is another example from Germany in the 13th century. You can see many more sources and styles from going to this Wikipedia article. It seems fair to say that Jews would not want to say the blessing of "crowning Israel with glory/splendor" over an article of clothing they were forced to wear by non Jews in order to humiliate them.
In more recent times Jews were not forced to wear distinctive types of hats or clothing and many took the custom to wear clothes that didn't make them stand out by copying their non Jewish neighbors. Many theorize that this led to the wearing of hats that we see by Hassidic Jews in our days. When this officially began to happen is hard to tell.
Comment: Probably because only certain Rambam based groups are the only ones who think that's proper practice. Come on.
Comment: Your Ashkenazi source clearly says a hat would be fine for the blessing but people walk around bareheaded so they don't say the blessing.
Answer: The idea of a religious head covering seems to have been a מנהג since ancient times, as seen in Sepher Shemuel II 15:30

לוְדָוִ֡ד עֹלֶה֩ בְמַעֲלֵ֨ה הַזֵּיתִ֜ים עֹלֶ֣ה | וּבוֹכֶ֗ה וְרֹ֥אשׁ לוֹ֙ חָפ֔וּי וְה֖וּא הֹלֵ֣ךְ יָחֵ֑ף וְכָל־הָעָ֣ם אֲשֶׁר־אִתּ֗וֹ חָפוּ֙ אִ֣ישׁ רֹאשׁ֔וֹ וְעָל֥וּ עָלֹ֖ה וּבָכֹֽה
And Daveed ascended upon the Mount of Olives, and weeping as he went up with his head covered, and he went barefoot; all of the people that were with him, each man covered his head and wept as they ascended
Comment: Back then with turbans, and now with fedoras, as was the style several decades ago. I think they're outdated honestly
Comment: This seems to be a custom of mourning/crying.

Origin of wearing a hat


What should I do with amulet of Talos?

Question: Greta asked me to take it from catacomb. After that I return to her. I suppose I gave that thing to her. The problem is it's still in my hand. It's marked as stolen. Thus, anytime I get caught it will be gone. What should I do with it? I want to check whether I really have completed "Return to Grace" quest, because I'm not finding the quest in my journal.
Comment: I am supposed to give that amulet. Turns out I finished the quest and the amulet is still in my hand. Also it's marked stolen. So what do people usually do with it.
Answer: This quest has multiple bugs.
To complete it, all you have to do is return the amulet to Greta.
If you've done that, and it's not complete, you've probably encountered one or both of these bugs, taken from the linked wiki page's Bugs section:

If Roggvir's Amulet of Talos is taken before this quest, any Amulet of Talos picked up after that will be marked as a quest item and cannot be dropped or sold.
This quest may stay in the miscellaneous quest section even after completion.

The reward for completing the quest is just a leveled pile of gold, so it's not something to really worry about, even if having it in your quest list is ugly and bothersome.
Comment: Thank you for being the only one to actually supply a link that is directly related to OP's question, and not just a google search or the general Skyrim wiki.
Answer: That quest has several bugs, you should install the Unofficial Skyrim Legendary Edition Patch which fixes most of the issues people may encounter with the game.
In doubt always consult http://uesp.net, it contains everything you ever want to know about The Elder Scrolls games and lore.

What should I do with amulet of Talos?


XNA 3.0 to 4.0 conversion causes a viewport 'merging' to go awry

Question: I have an old XNA 3.1 game with a 2D camera, that I recently converted to XNA 4.0.
I had the camera zoom by creating a new viewport, setting the bounds to the camera width/height, and then kinda 'merging' them like this:
Viewport viewport = new Viewport();
viewport.X = 0;
viewport.Y = 0;
viewport.Width = camera.DisplayWidth;
viewport.Height = camera.DisplayHeight;

Viewport priorViewport = this.GraphicsDevice.Viewport;
this.GraphicsDevice.Viewport = viewport;
GraphicsDevice.Clear(Color.Black);
DrawGameLayer(gameTime, "PreContent");
this.GraphicsDevice.Viewport = priorViewport;

However, when the new viewport's resolution becomes greater than the graphics device's viewport's resolution (on a zoom out) then it blows up on line 7, with:

The viewport is invalid. The viewport cannot be larger than or outside
  of the current render target bounds. The MinDepth and MaxDepth must be
  between 0 and 1. Parameter name: value

This worked perfectly before, but obviously is not the right way to do things now.  Is there a good way to quickly fix this?  Or am I stuck having to completely change how I zoom in and out?
Answer: There is a lot of examples for 2d cameras in xna... is the first time I see that kind of code...
viewport is not intended to do zooms... it defines a portion of screen to be drawn.
spritebatch.Begin(...,...,...,..., transform) is what you need to do camera transforms
your transform matrix can be similar to this....
Matrix CameraTransform = Matrix.CreateTranslation(-CameraPosition)
                       * Matrix.CreateRotationZ(rotation)
                       * Matrix.CreateScale(Zoom)
                       * Matrix.CreateTranslation(Viewport.Center);


Does anyone have a solution to 10.04 LTS not recognizing blank CD/DVDs?

Question: After I upgraded to the latest version, and I'm fully up to date, I can no longer burn CDs or DVDs, the OS simply will not recognize any blank media. Has anyone else been experiencing this and if so have you found a solution?
Comment: I had this problem too.
Answer: There has been a documented issue with this on the previous version of ubuntu. If you had upgraded your system the problem may still be persistent, simply due to the nature of the upgrade.
I would recommend a clean install.
Comment: I did a clean install and I had this problem too.
Comment: Ditto. I did a clean install and I still can't burn.
Answer: Does it detect other CD/DVD media? if not then problem lies with CD/DVD drive - the hardware.
Answer: I think this is a wide spread issue - there are lots of forum threads (eg. http://ubuntuforums.org/showthread.php?t=1544152, http://ubuntuforums.org/showthread.php?t=1539292) with similar issues.
It may help to update your kernel. Go to System -> Administration -> Update Manager and update all of your packages.
If there is no improvement, try installing the package linux (to install the latest kernel).
If there is still no improvement, you may need to use a ppa to install a newer kernel, that is not available from the repositories. I hear version '2.6.35' solves this issue with some people.
To install it, you need to add the repository: ppa:kernel-ppa/ppa
to your software sources. Then install: linux-headers-2.6.35-14, linux-headers-2.6.35-14-generic and linux-image-2.6.35-14-generic.
Answer: I Had the same troubles and did a firmware update with the DVD/CD-Drive and everything works well.
Answer: I always get this problem when the laser optics start to get dirty. It would read OK but not recognize blank media let alone try to burn them. A quick blast of air always fixed the problem. Get a can of compressed air and try it.
Answer: You do not give any clue what hardware you have. I had that problem (and suspend/hibernate issue) on an old Dell Inspiron 8200 laptop. It had a hot swap drive bay that had a DVD drive in it. But apparently because it could be hot swapped, Linux kept polling for a floppy drive, resulting in log errors attempting to read fd0, lack of auto mounting USB or CD/DVD's, and failed to suspend or hibernate because it could not put udisks-deamon to sleep, which kept polling for the non-existing floppy.
So if you have no floppy and are getting any fd0 errors in dmesg or /var/log/messages similar to "end_request: I/O error, dev fd0, sector 0", either disable the floppy in your BIOS, or if that does not work:
Add following to /etc/modprobe.d/blacklist.conf (use sudo or gksu to run your editor):
blacklist floppy
Then do: sudo update-initramfs -u
Then reboot and see if USB and other removable media auto mounts when inserted.
Note that other partitions on internal drives are not auto mounted unless you make proper mount points (usually in /media unless you want it mounted elsewhere) and entries in /etc/fstab (preferably using UUID). Although, they will mount if you have permission and select them in Places.