Clean up muddy water left after hurricane

Question: After Irma, 2 yrs ago, our floor was covered with a wet sticky mud.  I used a massive amount of towels to clean it up. Now I am wondering if a wet dry vac( preferably with a pump )  would make the job easier.  Your thoughts please?
Comment: @JimStewart, you normally remove the filter from a wet/dry vac when using it on liquids or wet materials.  That said, I wouldn't use one on mud.  Dirty water, sure, but not mud.
Comment: I would probably start with something like a [Squeegee Broom](https://www.homedepot.com/p/Quickie-2-in-1-Squeegee-Push-Broom-635SU1/202843362) to push the stuff into bigger piles or thicker puddles before scooping it up in a dust-pan or something similar.
Comment: I was part of a team cleaning a factory floor covered in water plus.., we used large brooms (4ft head) and shovels then big industrial wet/dry vacs but the shovels and brooms did the large part of the work...
Comment: Every shop vac I've ever seen has a float ball  captured inside the filter cage.  If the ball gets too close to the vacuum input, it is sucked up and plugs the input, making the vacuum go "SkrEEEEE" and stopping all suction.   Water rising in the vac moves it too close.
Comment: A shop vac would get quickly filled. The filter would get wet and covered in mud which would stop it up. I would scrape up as much as you can with a dustpan (or pair of them pushed together). Perhaps a snow shovel would work.  If the floors could be scratched by metal  implements, then plastic implements should be used. The mud would be dumped into a wheelbarrow, if you have one, or into buckets if you don't have a wheel barrow. Only after as  much as could removed by the above would I consider using a shop vac.
Comment: When you say towels I assume you mean terry cloth fabric towels, right? I would think that this would work much better than a shop vac. You would wipe the floor until the towel was full and then take it outside where it would be washed clean with a hose and then twisted dry?
Comment: @JimStewart the wet/dry vacs we used had a safety float to switch off the motor once the liquid got to the max height and there was still a "filter" to prevent excessive moisture passing through...
Answer: What I've done in the past for mud and other messes is to start with a garden hose to move the mud, using a basic sprayer head. You spray in an arc across the floor and try to get the water & mess flowing in the direction you want.  You can use the squeegee broom mentioned by brhans to help with this. The water not only helps liquefy the mess to make it easier to flow away, but the movement and pressure does the work of moving it for you. You don't even need a pressure washer to get most things clean this way.

If you get really good at this, you can not only get large amounts of mud/mess off the floor, but you can get nearly 100% of it off. I've used the technique so much and figured it out so well that mops were essentially unnecessary for several things I've had to clean off floors. Getting the water to move correctly will prevent puddles and will leave not much more standing water than a mop will.
How thick and/or how large an area it is you need to work with determines your starting point. If it's not thick and not a large area, start at the farthest point away from your exit or drain. This gives you the best shot at getting it done in the fewest passes. And don't worry about trying to clean it all in one pass. With something as messy as mud, it'll likely take several passes, even if there's not much there.
If it's a lot of mud/gunk or it's a large area, start closer to the exit or drain. This allows removal of sections of mess and helps prevent it from flowing back on your already cleaned sections.
If it's really thick, as in more than an inch, then you need to shovel it out first, using a flat bladed shovel, like the image below, or a snow shovel or scoop shovel. Depending on where you need to get it, a wheel barrow, like Jim Stewart mentions, could do the trick. If you can't get one through a door, then 5 gallon buckets can work in a pinch.

Images included for example only.
Comment: That was my first thought also.  However it depends on there being a downhill place for the water/mud amalgam to ultimately go, like a garage door or basement walkout.  You wouldn't want to have your sump pump pumping it... Maybe you could temporarily rip it out and replace with a dirty water pump.
Comment: @Harper, good point. A sump could handle some of it, if it's a dilute enough slurry, but not big chunks or really thick gunk.
Comment: Close to where I grew up the Russian river would flood every 10 years or so. We would use sprayers and large rubber squeegees to move everything out including the Sheetrock we had to cut out. After moving the solids and spraying a bleach solution and again water spray and squeegeeing was all we did to prep the homes. Today I would use hydrogen peroxide as the bleach stinks forever, no real smell to hydrogen peroxide and it cleans up any nasties  in the water.


As yeast is a fungus, are there any alcohol recipes that contain mushrooms?

Question: As fully asked in the question are there any alcohol recipes that contain mushrooms?
Answer: As yeast is a fungus, are there any alcohol recipes that contain mushrooms?
The short answer is yes, but you still need the yeast to start the fermentation.

Mushroom-Infused Beer Recipes
Below you'll find some basic beer recipes that incorporate mushrooms. Each recipe is sized to make 5 gallons of beer. However, given the broad range of ingredients available to homebrewers, you don't have to limit yourself to the ingredients you see here. You can modify any existing recipe. Just be sure to formulate your beer to balance sweetness and bitterness. And consider making it a specialty regional beverage that incorporates local and organically grown ingredients. Have fun making your first mushroom beer, and "hopfully" many more!
Turkey Tail Ale
A golden pale ale with turkey tail (Trametes versicolor)

6 pounds extra-light malted grain

4 ounces fresh or 2 ounces dried turkey tail mushrooms
1 ounce hops
Ale yeast

Iceman Amber
An amber ale with birch polypore (Piptoporus betulinus) and amadou (Fomes fomentarius)

6 pounds extra-light malted grain
1 pound amber malt

12 ounces carrot juice (preferably organic)
4 ounces fresh or 2 ounces dried birch polypore mushrooms
4 ounces fresh or 2 ounces dried amadou mushrooms
1 ounce hops
Ale yeast

Reishi Red
A natural red lager with reishi (Ganoderma spp.)

6 pounds extra light malted grain
1 pound amber malt

12 ounces red beet juice (preferably organic)

4 ounces fresh or 2 ounces dried reishi mushrooms
1 ounce hops
Ale yeast

Agarikon Stout
A dark, earthy brew with agarikon (Laricifomes officinalis, Fomitopsis officinalis)

1 pound chocolate malted grain
1 pound crystal malted grain
5 pounds pale malted grain
2 ounces liquid agarikon mushroom extract (from colonized grain)
1 ounce hops
Trappist yeast

Note: Agarikon is endangered and should not be harvested in the wild, but it is a powerful medicinal mushroom worthy of a stout beer. Since this mushroom cannot be cultivated in large quantities and the mycelium is slow to grow, the best option for this recipe is to allow myceliated cakes to supercolonize over the course of several months, until they are thick with biomass, and then prepare an extract from them. - Brew Outside the Box: Making Mushroom-Infused Beer

Technically speaking, working with mushrooms doesn't pose any major technical hurdles during the brewing process, making it an easy ingredient to play around with, although approaches vary by brewery. Some infuse whole dried mushrooms into the wort (the water extracted during the mashing process), transforming the hot liquid into a sort of mushroom broth, which is then fermented and bottled. Others dry mushrooms and grind them into a powder, which is then made into a tea and added to the beer after fermentation is complete.


What is the entailment of this sentence?

Question: I found that most of the examples of entailment are statements about a third person, but never the speakers themselves. So I wonder what the utterance like "I'm cold." entails?
Answer: This is a pretty broad question. "I'm cold" without any other contextual details entails any number of things. Basically any entailment means "if A, then B; A therefore B".
So if "I'm cold." then

I exist.
I sense ambient temperatures.
The temperature I experience can change.
I have a concept of hot/cold.
The temperature I am experiencing is in the range of what I would define as "cold".

If you get creative, you could probably come up with a dozen or so more entailments for this simple sentence pretty easily.
One reason entailments are more often about 3rd persons rather than 1st is that there is a distinction between presuppositions and entailments. Speakers have presuppositions, sentences have entailments. So the 1st-person sentence "I'm cold" entails certain presuppositions that the speaker has. And since the speaker and the subject of the sentence are the same, it makes distinguishing entailments and presuppositions a little trickier whereas with 3rd-person sentences, the presuppositions of the speaker do not have a direct impact on the entailments of the sentence.


Rust map with locations?

Question: How do the locations in Rust obtained from /location correspond with the world map? What are the locations of the rad towns?
Answer: You can enter co-ordinates here:
https://rustmap.net/
Comment: While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference.  Link-only answers can become invalid if the linked page changes.
Comment: He can provide more info about the answer and the link itself. "Type here and you find what you are looking" is not a good answer for ArQAde. The idea is, you came here to find an answer HERE. even if the answer leads to another place, you already have an idea on how to solve your problem without leaving the site.
Comment: @Michel I personally don't think that's applicable since the link is to an interactive service. The post could certainly be improved by adding an answer for the second question, but it answers the first one relatively well.
Comment: [There is a large and ever-growing debate on link-only answers.](http://meta.stackexchange.com/questions/tagged/link-only-answers)  StackExchange generally frowns on such answers, due to the reasons already laid out by @Michel.
Answer: http://rustmapmarks.com/RustLocalizer.php
There you can find the coordinates when you mouse over the map.
http://rustmapmarks.com/maps.php?h=0QDSm4PsDJ1TI
There is a map with the most known places marked, mouse over the icons for the coordinates.

Rust map with locations?


How to run an existing REACT project

Question: Beginner here, please help.
(1)If I have the files of a react project which was built on codesandbox or by another dev, how do I run the app and make changes in VSCode on my own machine.
(2)How do I run an existing personal create-react-app project on my machine, so as to continue buliding?
Comment: in the terminal run `npm install` and then `npm start` https://ccoenraets.github.io/es6-tutorial-react/setup/
Comment: Pretty much just [npm start](https://www.youtube.com/watch?v=rUdOf63M_WA)
Comment: This might help: [run existing react app in vscode](https://www.youtube.com/watch?v=rUdOf63M_WA)
Answer: Open a terminal on vscode, then make sure you already node installed.
Type npm install after that npm run start or whatever command to run, you can see on package.json.
Answer: If you accidentally closed VS Code or your local server tab, you can manually go to the folder, then right click and choose open in terminal, "open your project folder in terminal". Run npm start.
It will start development server with hot reloading at http://localhost:3000/
Answer: The first thing you need is to install updated version of nodejs, you can type to google "download nodejs" and make sure you download the stable version.
You need to open a terminal, also make sure you can locate your file path then type:
cd your file path: your-appName (this should be the name of your app)

How to run an existing REACT project


Which spell in Dota 2 has the largest Area of Effect?

Question: I think Phoenix's Supernova, Naga Siren's Song of the Siren and Tidehunter's Ravage have big Area of Effect radii. It would be fun to know which spell has the largest Area of Effect.
Which spell in Dota 2 has the largest Area of Effect?
Answer: There are a few contenders, but tied for first are Broodmother's "Spin Web" and Phantom Lancer's "Doppleganger" abilities, each with a radius of 900 units.
When looking at abilities that have offensive capability, the largest area of effect ability goes to Disrupter's "Static Storm", using a level 25 talent to increase the radius from 500 units to 775 units.
Without needing to level or improve the ability with talents or items, the largest offensive area of effect ability goes to the Techies' "Focused Detonation", with a radius of 700 units.

Broodmother's "Spin Web"
Broodmother's "Spin Web" ability creates a web that covers a radius of 900 units. The ability does not provide any offensive ability; that is, the Broodmother has increased movement speed when walking on a web, but they do not damage enemies.

"Spins a large web that grants Broodmother a passive movement speed increase, gives free movement, and boosts regeneration while in its vicinity. Spin Web charges restore every 40 seconds. Spin Web can be cast from anywhere as long as the new web touches an existing web. Webs never expire, and can be manually destroyed. When the maximum limit of webs is exceeded, the oldest web disappears."
- Description of Broodmother's "Spin Web" abiliy @ The DOTA2 Wiki

Phantom Lancer's "Doppleganger"
Phantom Lancer's "Doppleganger" ability allows both the player and any nearby illusions to teleport to another location. The initial area of effect comes in targetting the nearby illusions, and covers a radius of 900 units surrounding the player. All illusions reappear within an area of effect radius of 325 units.

"Phantom Lancer briefly vanishes from the battlefield. After 1 second, Phantom Lancer and any of his nearby illusions reappear at a random position within the targeted location, along with two additional doppelgangers. Extends duration of all illusions. The two added doppelgangers have different properties: one takes normal damage and deals none, while the other takes 500% bonus damage and deals 80% less damage."
- Description of Phantom Lancer's "Doppleganger" ability @ The DOTA2 Wiki

Disrupter's "Static Storm"
When looking at damaging effects, Disrupter's "Static Storm" comes in as the largest area of effect, with a radius of 775 units. This requires a level 25 talent that increases the radius up from 500 units.

"Creates a damaging static storm that also silences all enemy units in the area for the duration. The damage starts off weak, but increases in power over the duration."
- Description of Disrupter's "Static Storm" ability @ The DOTA2 Wiki

The Techies' Focused Detonate
When looking at damaging effects without the use of talents, the Techies' "Focused Detonate" ability comes in as the largest area of effect, with a radius of 700 units. The actual effect is that it triggers the detonation of mines, which need to be pre-placed by the player to damage enemies.

"Detonate all remote mines in the target area."
- Description of the Techies' "Focused Detonate" ability @ The DOTA2 Wiki
Answer: There are several abilities with a global radius.
Bloodseeker's Thirst gains benefits based on enemy heroes' health wherever they are on the map, and provides vision globally when a hero falls under 25% of its max health.
Chen's Hand of God heals allied heroes and units under Chen's controls wherever they are on the map.
Crystal Maiden's Arcane Aura provides mana regeneration to allied units wherever they are on the map.
Lycan's Feral Impulse is an aura that increases attack and health regen of units under Lycan's control, wherever they are on the map.
Omniknight's Guardian Angel renders allies immune to physical damage and, when upgraded by Aghanim's Sceptre, has global radius.
Silencer's Global Silence applies silence to all enemy units, wherever they are on the map.
Spectre's Haunt creates an illusion next to each enemy hero, wherever they are on the map.
Troll Warlord's Rampage, unlocked through the Aghanim's Shard, provides attack speed or status resistance to all allied heroes, wherever they are on the map.
Zeus' Thundergod's Wrath deals damage to all enemy heroes, wherever they are on the map.


Causes of screen tearing and vsync

Question: Is there an explanation of whats going on from the software down to the hardware that explains tearing? One would think that the graphics card would just tell the LCD display to change whenever it wants to. Why do LCD displays have refresh rates at all?
Answer: Sometimes your video card is faster at drawing than your monitor can possibly refresh, due to its hardware. It will have drawn out a full frame and then started work on the next frame (filling up the buffer with this new data) but it only gets 25% into it before the monitor comes along and grabs the buffer to draw the screen. The buffer it has grabbed is then a frame some fraction completed, but it renders anyway.
If you're moving really fast the difference between the two frames might be pretty dramatic, which looks like a 'tear'. If you're not whipping around it might not be noticeable at all. Vsync instructs the video card to only send up whole frames to the monitor accessible buffers, so the monitor is never in a position to grab a partially written to frame.
It does this by instructing the video card to only write one frame to the buffer and only to do so after the monitor has grabbed the previous frame. This effectively limits your FPS to your monitor's refresh rate.
On why monitors have refresh rates: It's the hardware involved. High end TVs have very high refresh rates (~500+) but you probably don't want to spend the money on a monitor when you're not even going to be able to tell.
Comment: How does an LCD display end up having a refresh rate. A refresh rate on old CRT monitors makes sense because there is an electron beam, but LCD displays don't have that.
Comment: There's still a hardware controller that needs to take in input (the frame buffer) and translate all the data to the screen. It's not an instantaneous operation and there's a limit to how fast it can be done. There are in fact monitors that have very high refresh rates, but the human eye has difficulty detecting much beyond 30 fps, so it's not typically worth the additional cost for most people.
Answer: Even if there's no electron beam, you're still sending the information to the monitor in the same order, over time.  How often you send an entire screen's worth of information is, more or less, the refresh rate.
Consider that LCD pixels take time to change from one value to another.  Even if your hardware used a lot of bandwidth to send a very high number of frames to the monitor each second, you'd still have to use pixels which could change fast enough to make that meaningful.  So although there is no electron beam, there are practical limits to how fast an LCD can refresh.
And if you tell the video card to change what you're sending halfway through a frame, it will do so.  Hence, tearing.
Comment: Do you mean the LCD display has no memory for each pixel and relies on a stream of data from the GPU even if it is displaying a static picture?
Comment: That's more or less correct.  The video card sends the static picture in full, uncompressed, over and over.  See the Wikipedia article on DVI for details.  TFTs do act as a "memory" for each pixel, and a display can use memory for other purposes (e.g. motion interpolation) but the image is nonetheless updated with every refresh, static or no.

Causes of screen tearing and vsync


Codeblocks "Error resetting breakpoint..." can't debug

Question: This is my first post, so feel free to direct me elsewhere if this is in the wrong place.  I'm totally new to code::blocks, and I followed the directions (twice) from here to set it up with minGW.  Other than some expected warnings, it builds just fine.  However, when I go to debug it, I get the following messages:
Setting breakpoints Debugger name and version: GNU gdb (GDB) 7.4
Child process PID: 3928 [Inferior 1 (process 3928) exited with code
[037777777777] Debugger finished with status 0

When I set a breakpoint, I get the following:
Setting breakpoints
Debugger name and version: GNU gdb (GDB) 7.4
Child process PID: 3092
Error in re-setting breakpoint 2: Function "C:/Users/Me/Documents/My Code/MyProgram/MyProgram/main.cpp:5" not defined.
[Inferior 1 (process 3092) exited with code 037777777777]
Debugger finished with status 0

I have searched and searched, but I haven't found anything.  The only relevant posts on this site,
CodeBlocks Breakpoints Ignoring Scope
codeblocks debugging
How to debug in Codeblocks?,
have not helped me at all.  I've reinstalled everything twice and I have no idea what else to do to get this debugger working.  Any help at all would be appreciated.
EDIT:  I made "Hello World!" and it ran, but still could not be debugged.  No idea what the problem is, especially since it detects gdb.
Answer: This error occurs if there is a space in your build path (in your case "My Code").
Just rename that directory or move the project to a place where there are no spaces in your path.
Reason:
Ref this link: http://wiki.codeblocks.org/index.php?title=Debugging_with_Code::Blocks#Path_with_spaces
You may have to clean and build your project again
Comment: had the same problem with cdb - removing space from path helped. A LOT :)


How to handle captcha in Jmeter?

Question: I have created a test plan for a user for a web application. The test plan is running as expected, but on the registration screen, the user has to enter a captcha. I'm not able to handle it from Jmeter.
Comment: Please frame the question with concrete details. What have you tried? What is failing ?
Comment: I have created a test plan for a user for a web application. Test plan is running as expected but on registration screen, user has to enter capcha. I m not able to handle it from Jmeter. After goggling I found a solution on stack over flow.
Comment: I found this on stack overflow:
 1. Create a Beanshell Sampler

In it, the following code displays the captcha and waits for user input

filenameOrURL = new URL("${captchaimage}");
image = Toolkit.getDefaultToolkit().getImage(filenameOrURL);
Icon icon = new javax.swing.ImageIcon(image);

JOptionPane pane = new JOptionPane("Enter Captcha", 0, 0, null);
String captcha = pane.showInputDialog(null, "Captcha", "Captcha", 0, icon, null, null);
Answer: Solution is here :
https://stackoverflow.com/questions/6964358/jmeter-testcases-which-can-handle-captcha
Or you can disable captcha from code before test.
Answer: The whole point of adding captcha security is to stop an automated tool to access the website.
It is not completely possible, but if you are able to handle that using Jmeter or another tool then its security bug as anyone can run an Automated test on your environment.
There are some ways to manage/handle, you need to get the following things from app/ development experts:

To disable CAPTCHA validation for testing purpose.
To make the CAPTCHA as static- Make certain it sends only the same value
each time.
To send the CAPTCHA value in server response-(with the intention that you
can correlate)
Provide the CAPTCHA details which are come in the database in sequence-
Basically, get it from the database and ensure it happens in series.

How to handle captcha in Jmeter?


Flex - objects floating at the top of a canvas?

Question: I want to have a canvas with some "floating" property. Basically when I add child to it, the child should float at the top. When I add the second child, it should float above the previous one.
For example the canvas width is 100, and I have two VideoDisplay with width 100 and height 75.
canvas.addChild(video0);
// Or canvas.addChildAt(video0, 0);
// video0 should be at x=0 and y=0
canvas.addChild(video1);
// Or canvas.addChildAt(video1, 1);
// video1 should be at x=0 and y=0, while video0 x=0 and y=75

I am not sure if this is do-able, via Flex SDK or any third-party library? Thanks.
Comment: Does it need to be a Canvas?  Sounds like a List that you are building up.
Answer: What you need to do is create a function that takes a DisplayObject, repositions the other children and then adds the child.
private var displayObjects:ArrayCollection;

public function addFloatingChild(object:displayObject):void
{
    // loop through displayObjects to set new positions
    for(var i:uint; i < displayObjects.length; i++)
    {
        // logic for new position
    }

    // keep reference to child
    displayObjects.addItemAt(object, 0);

    // this will always put on top of other children
    // this will always position at 0, 0
    this.addChild(object);
}

Answer: I just googled a little, and found a very helpful third-party library flexlib. For those having the same demand, flexlib offers a FlowContainer that will meet your need.


Sound output starts delayed. Cant force sampling rate on boot

Question: Whenever the PC boots and I start playing some audio, HDMI audio starts playing after 3 seconds. Before playing any audio file, if I run this command: pacmd list-sinks | grep sample, I get this output:

sample spec: s16le 2ch 44100Hz
sample spec: s16le 2ch 44100Hz

After playing some files and experiencing the 3-second delay, if I rerun the same command, I see this output:

sample spec: s16le 2ch 48000Hz
sample spec: s16le 2ch 44100Hz

Therefore, I assume the delay is due to changing the audio sample rate from 44100Hz to 48000Hz. In order to force 48000Hz on boot, in the file /etc/pulse/daemon.conf  I updated the values to:
; default-sample-format = s16le ; default-sample-rate = 48000 ; alternate-sample-rate = 48000
Also in files /etc/pulse/default.pa and /etc/pulse/system.pa have commented out load-module module-suspend-on-idle.
However, on boot, the sample rate remains at 44100Hz for both cases. Any help is appreciated.
Comment: Hi - please add the Ubuntu version that you are using so others can help as best as possible.
Comment: Ubuntu 22.04.4 LTS
Answer: If you look above, you will see Default values are commented out.  Use either ; or # for. Remove the ; to uncomment the lines:
default-sample-format = s16le
default-sample-rate = 48000
alternate-sample-rate = 48000

Comment: Audio is distorted on boot. I added `pulseaudio -k` in _Startup Applications Preferences_  App to solve the distortion issue
Comment: At least you have your sampling rate working like you wanted. If you want to fix the distortion, which is not a simple thing to fix, you should post a new question, and include sound hardware information like `lspci ; aplay -l`


Approximation of the binomial distribution

Question: Let $S_n=\dfrac{B_n - np}{\sqrt{n\cdot p\cdot (1-p)}}$ be a random variable which has the standardized binomial distribution. From Chebyshev's inequality I know that $$P(|S_n| \ge x) \le \frac{1}{x^2}$$ Is there also a good approximation of the form $P(|S_n| \ge x) \ge \ldots\,{}$?
Comment: Chebyshev's inequality applies to all distributions on the real line, not just to binomial distributions.  But you've specified a binomial distribution.  There may be inequalities of the sort you seek that would apply to binomial distributions but not to other distributions.  It's unclear whether such an inequality would answer your question.
Answer: Start by expressing the binomial distribution as
$$
P(B_n = k) = \binom{n}{k}p^k(1-p)^{n-k}
$$
so that
$$
P(|S_n| \leq  x) = \sum_{i=np-x\sqrt{np(1-p)}}^{np-x\sqrt{np(1-p)}}\binom{n}{k}p^k(1-p)^{n-k}
$$
and express
$$
\binom{n}{k} = \frac{n!}{k!(n-k)!}
$$
Then use the Stirling approximation with the first 2 non-trivial terms:
$$
\sqrt{2\pi n} \left(\frac{n}{e}\right)^n e^{\frac{1}{12n}-\frac{1}{360n^3}} < m! < \sqrt{2\pi n} \left(\frac{n}{e}\right)^n e^{\frac{1}{12n}}
$$
This yields really tight bounds on $P(|S_n| \leq  x)$.
Answer: For large values of $n$, $S_n$ has a CDF that is well-approximated by the CDF
of a standard normal random variable. Thus, one approximation to a
lower bound is
$$P\{|S_n| \geq x\} \geq  \sqrt{\frac{2}{\pi}}\left (\frac{1}{x} - \frac{1}{x^3}\right )\exp(-x^2/2)~~ \text{for}~~ x > 0.$$
The corresponding upper bound is
$$P\{|S_n| \geq x\} \leq  \sqrt{\frac{2}{\pi}}\frac{\exp(-x^2/2)}{x}
~~ \text{for}~~ x > 0.$$
See, for example, this answer for
details on how to arrive at these bounds.


How to make a facebook app that automatically shares posts from a facebook page on my personal account?

Question: I have a page and every time I post an update, I have to ask my Social Media team to share it from their personal accounts to increase the reach. I wish to automate this process by making a facebook app.
The app is supposed to share every new post automatically from accounts of those who signed up for the app.
I tried to look up for such apps, but couldn't find any. Is there some constraint that doesn't allow the existence of such apps?
If no, how can I create one? I have fair coding skills but haven't worked on developing a facebook app before.
Thanks.
Answer: Autosharing/Autoposting is not allowed, prefilling is not allowed either.
Platform policy: https://developers.facebook.com/policy/
That being said, publishing on a user wall is explained in the API reference, including example code: https://developers.facebook.com/docs/graph-api/reference/user/feed#publish
Comment: Hey, thanks, but then how come apps like Thunderclap auto-publish content?
Comment: if they do autoposting and prefilling, you should report them. the facebook terms are very clear about it.
Comment: The policy says _Obtain consent from people before publishing content on their behalf._
and I completely agree with that.
The app I wish to make only posts after the user allows it to.
Comment: how about the prefilling part? did you read that? either way, i have included a link to the docs too, there is example code.


What blueprints become available during story?

Question: As I progress, I realize that some blueprints open up throughout the story and don't have to be researched. Are these random or are they always the same and is there a list over those? Seems you can easily waste research point if you don't know that.
Comment: There's a difference between research and development in the game. Research is just making the development of something available. Often developing something ahead of the automatically unlocked research what you want to go for because by the time it becomes "common" in the game world (i.e. you can just develop the item), it's obsolete, or at least the bare minimum to have any fighting chance, so - what you're asking isn't really so much a defined list - your answer is: level first,  always based on missions, level, and relationships.
Answer: The blueprints, which are automatically unlocked are never even shown on the research screen. You simply unlock all the common research projects whenever you reach the required level+1. I.e. once you reach Lvl 21, you get access to all common level 4 blueprints.
Additionally you also get access to new nomad blueprints at those intervals. Those cannot be bought or researched either.
List of automatically unlocked research projects:

Possibly incomplete, feel free to add, if I missed something.

M-8 Avenger Assault rifle
M-96 Mattock Assault rifle
Incisor Sniper rifle
Viper Sniper rifle
M-23 Katana Shotgun
Disciple Shotgun
M-3 Predator Pistol
Carnifex Pistol
M-5 Phalanx Pistol
Biotic amplifier melee weapon
omni blade melee weapon
Pathfinder Armor set
Intitaitve Armor Set
Maverick armor set
all nomad blueprints
Comment: I can't speak for the asker, but I interpret the question as asking for a list of what these common research projects are. In other words, a full answer should have the names of guns and armor in it.
Comment: from what I can see he is mostly concerned about wasting research points on projects, which he gets automatically. But that can't happen as you cannot spent research points on automatically unlocked projects. I'll add a list to my answer, though it may be incomplete.
Comment: Not at my Xbox to confirm, but I think you're probably missing the Charger and Viper.
Answer: To clarify, these are the tiers where the various automatic upgrades are unlocked (as well as where things like Mods level up in vendors inventories):
Tier I: Level 1
Tier II: Level 6
Tier III: Level 11
Tier IV: Level 21
Tier V: Level 31
Tier VI: Level 41
Tier VII: Level 51
Tier VIII: Level 61
Tier IX: Level 71
Tier X: Level 81
There are no further tiers.
Comment: Yeah, but for which weapons do you automatically get access to those tiers?
Comment: The tier rules don't apply to some of the Remnant gear. I have a Tier X chest plate and not even half way to level 81. I also have a level VII legs and not level 50.


Screen Sensitivity of the retina display iPad (3rd generation). Is it better than before?

Question: Does the new iPad support higher resolution tapping, or just more pixels for display. Stylii and the existing iPad feel like writing with a big marker on a big index card. Will the new iPad feel more like pen-and-paper when using a stylus?
Comment: Not really an answer to your question, but worth mentioning it. A while ago their was [a great project](http://www.kickstarter.com/projects/531383637/jot-capacitive-touch-stylus?ref=live) on KickStarter, Jot. It was an ultra sensitive stylus for your iPad. And although it's not available anymore by KickStarter, you can still buy it on [their website](http://adonit.net/). It really worth the money!
Answer: I practice, I can't tell any difference at all between the two models for most finger gestures on non-drawing apps.
Two things make this measurement hard - we don't get to see the raw pressure points and the unsmoothed and smoothed multitouch input. The end result of touch is highly processed which could easily hide changes in the detection grid / chip that does the processing / algorithms or tuning to make one iPad feel like the others.
The other is that our fingers cover the area we are selecting and for fine adjustments, you don't have to actually move your finger - just roll it to change the contact area of your deformed finger pad area that is either in direct contact or close proximity to the glass surface.
Once I learned to pivot and wiggle my fingers in place rather than try to slide it for fine adjustments - my precision (and feel of being able to control the precision) jumped immensely.
On the other hand - drawing with a stylus or deft and rapid strokes with a finger in a good drawing program makes the end feel on a retina iPad much better than before. I don't know if this is mental or real, but getting a finer line out of the same repeated gestures is incredible and makes the new hardware feel much more like pen or pencil and paper to me. I can't tell if it's the CPU/GPU or hardware or illusion, but the feel is quite real after a short adjustment period.
Comment: For what it's worth, I found I was far more accurate on my iPhone 3G than on both my 4 and 4S.
Comment: Thanks. What drawing program do you use? None of mine have updated to the higher resolution yet (nor would it matter as I don't have a new iPad). Also, is your stylus still a big finger-like pad, or do you have a stylus with a 'sharper' tip?
Comment: I'm using the cosmonaut and my finger exclusively. When I want a finer line, I increase the zoom factor. (programs are pre-release)
Answer: Only if you file your fingers down to double precision ;)
But seriously, no, the actual capacative touch screen layer is unchanged, because the thing that is needs to interact with (your finger) remains unchanged.
To take a simple drawing application as an example, drawing a spiral will receive input from your fingers in the same way as on an iPad or iPad 2.  It takes the locations of your touch and tries to take an average of the "centre" of your touch point and this will produce the same results, although when translated into your drawing the enhanced resolution allows the touch algorithm to smooth out the centre area to a slightly more accurate level which may result in a more accurate looking drawing, but it's not due to any resolution changes in the touch sensitive layer, just a more accurate rendering of the existing input.
Comment: "could be useful", could being the operative word.  But the essense of locating your touch input is to calculate what it considers the center point of any touch contact, and providing an x/y co-ordinate to produce a pixel location.  that location has by it's nature to be at a "higher resolution" that previously, but it doesn't mean that it's actually any more accurate.  The premise isn't flawed in my view, it doesn't matter if you use a finger, a stylus, a sausage or a moon rock, it calculates the center point the same and smooths the input - the rest is just maths.
Comment: I should note that using a stylus does not necessarily improve the accuracy of any touch input, it's merely allows you to *see* where you are touching with more clarity, hence the illusion of greater fidelity.
Comment: Your premise is flawed, as I don't interact with my finger, I interact with a stylus. Therefore, the higher resolution could be useful. You state that the capacitive touch screen layer is unchanged. Do you know this, or are you just guessing this because your finger is unchanged?
Comment: But a stylus is a smaller point than a finger. Or a moon rock... You're answering a question about a precise input device with comments about sausages. I'm confused...
Comment: That was exactly my point (if you excuse the pun), it doesn't matter how large or small your pointing device, it's "centre" is the same.
Answer: There is definitely a difference in screen touch sensitivity between the iPad Retina and the iPad 2. The former has a harder feel and is less sensitive to the touch. I still prefer using my iPhone 5 for everything even though the screen is smaller, the feel is so much better and way user friendly / faster on the touch.
As for stylus: the best for your iPad is Maglus by Applydea (love it!)
And for very fine writing and intricate stuff: Adonit Jot Pro.


UI Suggestion for switching apps

Question: Scenario : Just like in google switching apps from the top right corner cube button, where the user can quickly navigate to gmail, gdrive etc. I have kept the switching of app on the left side with a down arrow. Is the down arrow a good approach for letting the users know that from there the apps can be switched?

Answer:
Is the down arrow a good approach for letting the users know that from
  there the apps can be switched?

No.
You need an icon to hide Apps under it; icon finder is suggesting similar to Google or MS Outlook type App Icons:

Users have formed a specific mental model with dropdown arrows, they will think that the content hidden under Platform dropdown will be related to Platform service. They won't expect some another app or service to be hidden under it.
But, the label of that dropdown arrow can be helpful: More Apps
Comment: But in the same top bar, we also have other 4 btns like search, user profile, notifications and requests. So when in responsive mode, all the icons come together and doesnt look good.
Comment: @DivyanshPatel Place them on top with proper space - adjust the layout differently for different screens so that it doesn't appear cluttered. See how Google does it for small screens.

UI Suggestion for switching apps


Why could these characters use Force heal but not Anakin?

Question: In Star Wars Episode IX: The Rise of Skywalker we see Force heal used at multiple points by Light Side users. However in Star Wars Episode III: Revenge of the Sith it seems that this is a Dark Side exclusive power. Anakin doesn't know how to use it and Palpatine says that it's not a power you can learn from a Jedi. What's the explanation for this?
Comment: Honorable mention for Baby Yoda also.
Comment: Which *Jedi* do you see using it in TRoS? We see the last Jedi in that eponymous film, there are no more in TRoS.
Comment: @TylerH "I am all the Jedi' - Rey Palpatine (not Skywalker)
Comment: @DJSpicyDeluxe About as *technically* accurate as "*all the Jedi live in you now*".
Answer: The power that Darth Plagueis had was distinct from what was used in The Rise of Skywalker.
In TROS Rey and Ben use the Force to transfer their life between themselves and other organics, there is no new life being created, this is why Ben has to die to save Rey. On the other hand, Palpatine says that Darth Plagueis influenced the midichlorains to create life, ie he wasn't transferring life, he was creating new life.
Anakin probably could have transferred his own life to Padme but then he would have died instead, but if he could create life the way that Plagueis could then they could both survive.
Comment: I also doubt Palpatine would have given Anakin the hope of healing Padme, even if Anakin had to fully or partially sacrifice himself. He wants Anakin under his control; best way to do that is lie & obfuscate. Once he's under Palpatine's control, what's the first thing he does but lie to Vader saying that Padme is dead!
Comment: @elemtilas Padme was dead, Vader did (sort of) kill her. Palpatine wasn't lying.
Comment: D'oh! I meant Palpatine lying that Anakin actually killed her!
Comment: @DJSpicyDeluxe Palpatine had no way of knowing Padme was dead. He was *intentionally* lying and only *inadvertently* telling the truth that she was dead.
Answer:
Palpatine says that it's not a power you can learn from a Jedi. What's the explanation for this?

Palpatine was likely trying to manipulate Anakin.  Throughout the prequel trilogy, clone wars,...etc Palpatine is constantly manipulating different people to achieve his goals.  While it is possible that the power he described exists, he is more likely claiming its existence in an attempt to manipulate Anakin.
Comment: From Legends novels I'm pretty sure we had confirmation that this power existed. Under Disney's canon, I'm not sure.
Answer: I'm not sure that any of the Jedi during Anakin's time knew about Force heal.  We never see it used during the Clone Wars, a time where that ability would be very useful.  I think it is possible Rey learned it from the Jedi texts.  Then when she healed Ben, he learned about the ability and used it to save Rey later.  Before you ask, I'm sure Baby Yoda relied on his instinct or the will of the Force to use Force heal.
Comment: I would not call what Obi-Wan did Force heal.  It didn't look like what was used in The Rise of Skywalker and the Mandalorian.  But it is a possibility.  Perhaps the Force ghost of Qui-Gon taught Obi-Wan the ability.  We know from Revenge of the Sith and From a Certain Point of View that Qui-Gon popped in every now and then to teach/talk with his former apprentice.
Comment: Obi Wan (appears to) use it after Luke is attacked by the Sand People in IV.
Comment: Keep in mind, Obi Wan's scene was shot like 40+ years ago. I doubt Lucas had even a glimmer of ROS in his mind at that time, either story or cinematography! Anyway, his comment to R2 seems to indicate a sure knowledge of Luke's condition. Conjecture: living alone in the neighbourhood of the Sand People is as good a place to learn & practice force healing as any, just because in 20+ years alone, you're bound to have a run in or two!
Comment: I agree that Force healing was most likely not the original intention...but when has that ever mattered in Star Wars?  Also just because he knew Luke was going to be okay doesn't mean Force healing.  It could just be good old fashioned medical knowledge.
Comment: I don't disagree with your points, though the way he grabs at Luke's wrist doesn't instill much confidence in me that Obi Wan knows how to find, let alone assess a pulse!  It's the configuration of fingers on Luke's forehead followed by several moments of concentration that leads me to think this is some class of healing by Force.
Answer: In the Legends novel Shadows of the Empire, Darth Vader does use Force Healing. In the movie Empire Strikes Back, the time you see him with his helmet off-is actually a chamber he uses not only for communication, but also to focus his time into healing the permanent damage. In the SoE book, he uses as much hate as he can, but can only remain outside his breathing apparatus for something like 15 minutes, and it causes him pain to even do the act-using more rage to make himself last longer each time.
It may just be Legends, but it fits into the canon universe.
Comment: In the novels and in the movies, Bacta tanks for healing are a well-known healing method. Luke is also in a Bacta tank after his near-death experience in the frozen wastes of Hoth. Finn also wore a modern 'bacta suit' for nearly the entirety of TLJ. There's nothing Force-related about them so far as we know.


A classical universe from a quantum one?

Question: I don't understand how our quantum Universe suddenly becomes classical. If quantum mechanics governs everything - and accordingly nothing is determined - then how do we have a past history that goes back in time, classically, to the big bang?
Comment: Our Universe never becomes exactly classical. Clas. ph. holds approximately only. The history we believe going back to the Big Bang is a retroactive interpretation of the results of measurements we have (or a given observer has) made. It allows us to be "almost" sure about the value of many quantities (quantitative or qualitative descriptions of the events in the distant past) because those values or assumed facts are very likely to evolve to the future outcomes we have actually observed. But if we can't determine these answers about the past, then they are as undetermined as everything in QM.
Comment: So the past does not exist classically - i.e., what we see as a classical past is merely an approximation as to how quantum mechanics most likely evolved our Universe from time = 0?
Comment: Universal laws of nature like conservation of energy and momentum which govern development of the Universe hold for both classical and quantum worlds. Quantum effects are mostly local and quickly lose coherence with distance, so they become averaged etc.
Answer: How do we know anything? We look at things and make observations.
How do we do that? You need a system with enough parts that reliably work together so it can react to the thing you want to observe without being confused by every single other thing happening in the universe. If you are distracted by shiny objects you won't observe what you are supposed to.
Without this ability you wouldn't see a classical world and you wouldn't be able to observe anything. And the emergence of the classical world is made possible by this.  Becsuse if you can be insensitive to the rest of the universe then you can be insensitive to certain amounts of noise and error.
This means you can look at a large group of stuff and instead of observing it's exact state you observe some bulk average properties.
And when we talk about a classical world we don't mean that we see $10^25$ particles with particular locations and velocities. Our math might look like we think that bit it isn't actually what you see or experience.
You experience an interaction with your environment where you are sensitive to bulk properties of joint states of many systems.
And not everything happens just as often. And when you have many things it is harder for them to all act weird. It is like when you want to find the average height of people I'm some country. You could pick people at random, if you pick 1000 of them the odds that you picked the 1000 tallest people is unlikely. It could have happened. If you picked just one maybe the odds are poor you pocked on of the 1000 tallest but it becomes really harder if you picked 1000 at random that they were all so unusually tall.
So a lot of the possibilities just average out and you are set up to be sensitive only to the averages becsuse you have to be able to notice a bulk thing and not get distracted by every passing photon.
If you wanted to be sensitive to such things then an easy way is to shield something from all the distractions then have it interact with something that can be sensitive to that and then have something else interact with something sensitive to that and so on until you get something with bulk properties you can sensitive to.
But it is more than just that. There are two ways a configuration can evolve. One is based on be classical forces the system is subject to in that configuration. The other is a quantum effect that you can think of as a correct to that.  And all the weirdest parts of that correction are due to interference effects which require that the two configuration evolve to be close two each other. Just one part of the configuration being different means no interference. When you interact with something you make the thing interacting become different. So you change the configuration of that part so the entire configuration changes.
This washes out the effects that we call the quantum effects. Or the other way around. The effects that aren't washed out by interactions are called the classical effects.
That said there are macroscopic quantum things. Bose-Einstein condensates, lasers, superconductors, magnets.
Answer: Unlike in classical physics, in quantum physics there exists such a thing as a correlated state, different degrees of freedom can get entangled. Perhaps paradoxically, this feature of quantum mechanics gives rise to classical mechanics. What happens is that the degrees of freedom of any system will get entangled with those of the environment. A statistical description of only the system by averaging out the effects of the environment is then possible and then yields the effective classical behavior of the system if the system is large enough.
Now, it can be shown that the very notion of a probability always arises from quantum mechanics. There is no known application of classical theory of probability such that the invoked probabilities don't ultimately arise from quantum effects.


What if a passenger forcefully requested for a food which is not available on the flight?

Question: I'd never took long flights, however curios if one day I'll fly to NewYork from India and I wish to eat my favourite dish, which may not available in kitchen of my flight, what they will do? Is there something that I've to choose from the menu only? If so, I ordered one from the menu and its not available there? However I will force air hostess to get that particular dish for me, what can be done in this situation?
Comment: I feel this should go on travel.se
Comment: Yeah this is more suitable for Travel (although I'm not totally sure it's suitable there either) - you can take food on most flights, though, within reason.
Answer: There is only so much food on the plane while it's in the air. If the dish is not available then it is not available.
Should you then throw a tantrum and the flight-attendant judges that you are a danger to themselves or other passengers or the continued flight; the pilot will then divert the flight and throw you off at the nearest available airport. After that you may be fined for the trouble you gave them.
Comment: You can request (i.e. pre-reserve) a 'special meal' (e.g. vegetarian) when you buy your ticket. But you have to do that (let them know) in advance: it's too late after the plane takes off, and too late even when you check-in.


it's not against the constitution to arrest a pregnant woman in Bolivia

Question: In Bolivia my liberal party is about to make it illegal to arrest an pregnant woman and I am wondering if this goes against the portion of our Constitution that talks about equity before the law. Can anybody tell me if this is constitutional without modifying the Bolivian Constitution?
Comment: You have to tell us which country. It's not the US, so you don't want an answer based on US law.
Comment: I am in bolivia, but in almost evey roman based law it say the same "All are equal before the law and are entitled without any discrimination to equal protection of the law."
Comment: How do they plan on dealing with cases such as the pregnant woman committing murder, etc.?
Comment: Im wondering that too
Answer: It is difficult to say for sure. The Tribunal Supremo de Justicia would decide the constitutionality of such a law, and it's not possible to predict how they would rule. Article 168 of the Bolivian Constitution limits the president and VP to 2 terms in a row:

The  period  of  the  mandate  of  the  President  or  Vice  President
  is  five  years,  and  they may be reelected once for a continuous
  term

but a 11 months ago the court ruled (ruling not available anywhere that I find), but based on news reports) that this clause is contrary to a requirement under the American Convention of Human Rights that there is a protected right to be re-elected. While Art. 168 is pretty clear to me, the TSJ appears to follow different rules in interpreting the Constitution of Bolivia.
The law itself may set forth the constitutional basis for such a law. One might conjecture a connection with Art. 18 regarding health. The court seems to not have ruled on the person status of an embryo or fetus, so it could be reasoned that arresting a pregnant woman entails arresting an innocent person (which could be unconstitutional).
Comment: tjs has already stated that abortion is a right of a raped woman and with that logic we cannot consider a fetus a person with rights to be innocent or have live more than a piece of meat a woman wants to be removed so we are left with a health issue but ever the jail has medical care where a pregnant woman can be take care of her situation so I dont think there will be a risk for her health there


What are the advantages of TeXShop over TeXworks?

Question: The TeXworks homepage states that "It is deliberately modeled on Dick Koch's award-winning TeXShop for Mac OS X" and it seems that today people are using both. Both are delivered with TexLive and MacTex. TeXworks is available for Windows and Linux as well, what I consider a big advantage. TeXShop might have better OSX look&feel, but it is available for OSX only. So why should I use it, does it have advantages over TeXworks?
Comment: Related Question: [LaTex editor IDEs](http://tex.stackexchange.com/questions/339/latex-editors-ides)
Comment: Thanks, I thought about linking that question as well. I am also thinking about using [TexMaker](http://www.xm1math.net/texmaker/), [TexStudio](http://texstudio.sourceforge.net/) or [AquaMacs](http://aquamacs.org/), but this question is about TexShop versus TexWorks, because these two are delivered with MacTex by default and I just don't see too much difference between them. Which is why I'm asking...
Answer: TeXShop is a much more mature application, with a large user base and active development.
Some advantages:

Macro editor that allows you to attach commands or menu items to arbitrary chunks of code
Palettes of commonly used symbols and constructs
Simple table input editor
Macro to paste spreadsheet cells from Excel/Numbers etc. as LaTeX tabulars
BibDesk integration (automatic insertion of citations when BibDesk is open)
Native integration with aspell

The last two are very important for me. I have a soft spot for the fourth, since I contributed the code. :-)
Comment: @chang Very simply, if your `.bib` file is open in BibDesk, and you've allowed BibDesk completions in the TeXShop preferences, you can enter in your source `\cite{foo` and then hit Escape (or Tab depending on preference) and a list of all citation keys beginning with "foo" will appear as a drop down list next to the cursor. You then choose the right one and it gets inserted into your source.
Comment: Could you tell me how to use the BibDesk integration you mentioned? How does it work?
Comment: Current versions of TeXShop use F5 for BibDesk completion rather than the trigger for command completion (Tab or Esc).
Answer: One advantage that I have seen is that since TeXShop is a native Mac application, you get automatic spell checking available right in the editor.  Also, TeXShop seems to have more options for using menus to insert LaTeX code but I don't find that that useful, but am sure that others do.
I have used both and started with TeXWorks as it is available on both Mac and PC.  However, lately I switched over to TeXShop on the Mac just for the spell checking feature.
Answer: I understand the reason for the development of TeXWorks, but don't see why they are trying to develop on OSX anyway. TeXWorks is modelled after TeXShop, but does not have its advantages, and has (in my opinion) serious flaws.

At one point, the pdf renderer in TeXShop was better than in TeXWorks, but that may have been fixed. When I have both rendering the same file, the one in TeXShop is easier to read, but that may be contrast settings or something.
One reason for not giving TeXWorks a try is that the bright colors they use for icons annoys me.  If you look at TeXShop, it looks professional, it has muted colors and buttons that are obvious but don't get in the way.  I use TeXShop for hours on end, and if I had to look at such a UI disaster all of the time, I'd go looking for something else.
TeXShop has color highlighting of latex commands, and does brace completion (which is a lifesaver for me).  TeXWorks does not appear to have the first, though I don't know about the second.

Even if TeXWorks eventually gains the advantages of TeXShop, I don't see any reason to change.  TeXShop works well, and it has for years.
Again, I understand the reasoning for the development of TeXWorks, and I applaud it (even though I would have made some changes), I just don't see a reason to develop it for OS X as long as TeXShop is a viable alternative.
Comment: 3. TeXworks has syntax hightlighting, Format --> Syntax highlighting, or set it as default in the preferences.
Answer: TeXShop has direct support for Sage since version 2.25.  Sage.engine comes with TeXShop and you can activate it so that it will be available on the same drop down menu with other typesetting options like PlaneTeX, LaTeX etc.


How to verify the index on a table was created "Concurrently"

Question: Normally after I create an index, I check pgAdmin to verify that the index was created correctly. However, I'm not sure how to verify if the "concurrently" argument I passed in went through since I don't see it listed in the SQL Pane as I do with the other properties I've specified. Please help. Currently using version 1.22.1 connected to a PostgreSQL 9.5 server.
Answer: You would know that the index was created concurrently by observing the level of the lock on held on the table while the index was being built.
Once the index creation is done with, it is just an ordinary index.  Building an index concurrently is not an ongoing property of the index.


Does a dual-wielder get advantage on both attacks if hidden?

Question: If my rogue attacks while hidden and dual-wielding shortswords, do I have advantage on both of my attacks (from Two-Weapon Fighting) or only on the first attack?
Comment: While I have a reasonably good idea what you're asking (and it's not about makeup [rouge vs. rogue]), your question is full of non-standard terminology - "stealthed" (do you mean Hidden?), "surprise attack" is a Bugbear ability (the rogue ability is Sneak Attack), etc. Making your question as accurate as possible is important to make sure you get the answers to what you're actually asking.
Comment: What do you mean by "stealthed"? It's not a word in standard English, as it would be a past participle of stealth, which is not a verb, and therefore has no past participle.
Comment: What do you mean by "attacks while hidden"? If you attack in melee, you approach your target, so you are no longer hidden. Do you mean attack being invisible?
Comment: @DerekStucki It's English. If you can word it, you can verb it.
Answer: This is similar to When attacking while invisible, when exactly does invisibility break?, and to this Sage Advice.  There's also an informative Sage Advice podcast segment about stealth and attacks.
The answer is no; you reveal yourself on your first attack, unless you have a special effect that says otherwise.
Answer: Once you have made an attack, hit or miss, the character is no longer hidden. The only exception is characters with the Skulker Feat, which both greatly increases the places a character can hide (Light Obscurement is enough) and allows the character to remain hidden after missing with a ranged attack.
That said...

In combat, most creatures stay alert for signs of danger all around, so if you come out of hiding and approach a creature, it usually sees you.

Without some extenuating circumstances, you cease to be hidden before you make a melee attack. If you're able to make the attack, then you didn't have cover from the target enough to Hide in the first place.
For a rogue in melee combat, you're more likely to get Sneak Attack from an adjacent ally than being hidden. The ally doesn't grant advantage, but it is enough to allow Sneak Attack.
Other effects can grant the Rogue Advantage - darkness when the Rogue has darkvision, other forms of obscurement when the Rogue has blindsense (which they all get at L14), and so on. If the target doesn't have similar capabilities, the Rogue may get Sneak Attack. Being hidden doesn't matter in these case.
Either way, just in case it was unclear, a Rogue only gets Sneak Attack on one attack per turn, no matter how many they take. Of course, there are ways to attack on other people's turns, which could grant Sneak Attack more than once in a round.
Comment: @MarkWells All attacks in 5E are sequential, and by use of the phrase "first attack", the question seems to be aware of this fact.
Comment: I think the question here is whether the two attacks happen sequentially or at the same time. TWF requires you to make the bonus-action attack _when_, not "after", you take the Attack action.


The mishkan and the fencepost problem

Question: Rashi (Shemos 26:6, 26) counts out the number of poles for the chatzer (courtyard of the Tabernacle) on each side in parshas Terumah. He seems to ignore what is called the Fencepost Problem. The same problem exists for the 20 amah enclosure on the East side. Do any of the commentators address this?
Comment: You could improve this question by expanding on what Rashi says and how you see it as problematic.
Comment: I think it's unfortunate that this question has a bounty. It is entirely unclear, at least to me, what the question is, and I think it should probably be closed. @rikitikitembo, if you have a good idea of what's being asked here, please [edit] the post to be much more clear.
Comment: I don't have time to look into it at the moment, but my instinctive response is to ask you if he makes up for it on the perpendicular sides. If he is short one on each of the long sides, for example, is the missing post accounted for on the short sides?
Comment: @IsaacMoses Does pinging a bountier work?
Comment: @Shokhet I don't know. It didn't come up as a command-completion. I assume that a bountier would check in on bountied questions from time to time.
Comment: @IsaacMoses then again, close and reopen voters don't either auto-complete, and pinging works. I figure if it's part of the revision history there's a good chance it should work....and good point about coming back to check. ( *FWIW, I agree with you about the closure....if I get the chance I'll see what I can do about reading those Rashis and the linked WP page and see if I can clarify the question* )
Answer: If I understand correctly, you are referring to the brichim, the horizontal poles that were slipped through rings on the boards -- and through holes within the boards -- to hold them in place. The math is straightforward: There were 20 boards of 1.5 amos on the north and south, thus requiring the poles to span 30 amos (the top and bottom poles were 2 x 15 amos, and the middle pole 1 x 30 amos). On the west was 8 boards of 1.5 amos, which required the poles to span 12 amos (again, top and bottom 2 x 6, middle 1 x 12).
Now, the 8 boards on the west overlapped one amah of the ones on the north and south. But evidently the poles on the N and S sides did not extend over the thickness of the western boards. So the math works out perfectly.
Answer: As far as I understand, Rashi only says that there was a 5 amos span in between amudim in reference to the possuk discussing southern wall. He also explains that the south-eastern corner post was of the southern count and the 3 of the southern Shoulder are 15 amos towards the center and the same is mirrored on the northern side.
The question remains for the west wall. The possuk says there were 10 amudim so there must have been a different span, namely 50/9 amos.
The east gate masach must also have different spans. 20/3 = 6 2/3 amos because there were 4 amudim so three spans and 20 amos.
Ikur Sifsei chachamim assumes universal span and lays out in clockwise direction the next sides first amud holding up the end of each side and ends up  attributing this to rashi which doesn't work with rashi's explanation of the shoulders.
Comment: [Welcome to MiYodeya](https://judaism.meta.stackexchange.com/a/3887/11501) Nosson and thanks for this first answer. Great to have you learn with us!
Answer: Another possible answer is that in between each 5 amos span the amud itself took up space along which there was that much kela. Nine spans on the West and 19 spans on the North and South. Two posts in western corners. The shoulders' 5 includes the amud and the masach is back to a weird span or outsized amudim.
Another possible answer which doesn't fit with Rashi's expalanation of the corner amud is that each amud held the kela from the middle by suspending the kela on a roll from cords. the 5 amos span is still produced. Exactly how this was set up is not clear.
Answer: This is a question that has bothered people for a long time. Part of the problem is that even if you were to come up with an ingenious answer, it still wouldn't explain why Rashi seems to have left out whatever idea you came up with.
Now, to lay out the problem fully: The verses refer to a side as a peiah/פאה. Rashi to Exodus 27:9 defines that as the entire side. So you can't say that the poles in the northwest and southwest corner did double-duty for both sides, in order to gain another space on the north and south sides, because then there would be twenty-one poles to a side.
If you read the verses there carefully, you'll see that when describing the north and south side, the verse uses the singular "its poles", and when describing the west side, the verse uses the plural "their poles". The antecedent of the singular it would be the side/peiah, and the antecedent of the plural their would be the fifty amos of the west side.

(ט) {שביעי}  וְעָשִׂ֕יתָ אֵ֖ת חֲצַ֣ר הַמִּשְׁכָּ֑ן לִפְאַ֣ת נֶֽגֶב־תֵּ֠ימָ֠נָה קְלָעִ֨ים לֶחָצֵ֜ר שֵׁ֣שׁ מׇשְׁזָ֗ר מֵאָ֤ה בָֽאַמָּה֙ אֹ֔רֶךְ לַפֵּאָ֖ה הָאֶחָֽת׃
(י) וְעַמֻּדָ֣יו עֶשְׂרִ֔ים וְאַדְנֵיהֶ֥ם עֶשְׂרִ֖ים נְחֹ֑שֶׁת וָוֵ֧י הָעַמֻּדִ֛ים וַחֲשֻׁקֵיהֶ֖ם כָּֽסֶף׃
(יא) וְכֵ֨ן לִפְאַ֤ת צָפוֹן֙ בָּאֹ֔רֶךְ קְלָעִ֖ים מֵ֣אָה אֹ֑רֶךְ וְעַמֻּדָ֣ו עֶשְׂרִ֗ים וְאַדְנֵיהֶ֤ם עֶשְׂרִים֙ נְחֹ֔שֶׁת וָוֵ֧י הָֽעַמֻּדִ֛ים וַחֲשֻׁקֵיהֶ֖ם כָּֽסֶף׃
(יב) וְרֹ֤חַב הֶֽחָצֵר֙ לִפְאַת־יָ֔ם קְלָעִ֖ים חֲמִשִּׁ֣ים אַמָּ֑ה עַמֻּדֵיהֶ֣ם עֲשָׂרָ֔ה וְאַדְנֵיהֶ֖ם עֲשָׂרָֽה׃
(יג) וְרֹ֣חַב הֶֽחָצֵ֗ר לִפְאַ֛ת קֵ֥דְמָה מִזְרָ֖חָה חֲמִשִּׁ֥ים אַמָּֽה׃
(יד) וַחֲמֵ֨שׁ עֶשְׂרֵ֥ה אַמָּ֛ה קְלָעִ֖ים לַכָּתֵ֑ף עַמֻּדֵיהֶ֣ם שְׁלֹשָׁ֔ה וְאַדְנֵיהֶ֖ם שְׁלֹשָֽׁה׃
(טו) וְלַכָּתֵף֙ הַשֵּׁנִ֔ית חֲמֵ֥שׁ עֶשְׂרֵ֖ה קְלָעִ֑ים עַמֻּדֵיהֶ֣ם שְׁלֹשָׁ֔ה וְאַדְנֵיהֶ֖ם שְׁלֹשָֽׁה׃
(טז) וּלְשַׁ֨עַר הֶֽחָצֵ֜ר מָסָ֣ךְ׀ עֶשְׂרִ֣ים אַמָּ֗ה תְּכֵ֨לֶת וְאַרְגָּמָ֜ן וְתוֹלַ֧עַת שָׁנִ֛י וְשֵׁ֥שׁ מׇשְׁזָ֖ר מַעֲשֵׂ֣ה רֹקֵ֑ם עַמֻּֽדֵיהֶם֙ אַרְבָּעָ֔ה וְאַדְנֵיהֶ֖ם אַרְבָּעָֽה׃
9) You shall make the courtyard of the Tabernacle; on the southern side, southwards there shall be hangings for the courtyard, of twined linen, one hundred cubits in length for the one side.
(10) And its pillars shall be twenty, and their sockets twenty, of copper; the hooks of the pillars and their bands12 shall be of silver.
(11) And so for the northern side, length-wise, there shall be hangings of one hundred cubits in length, and its pillars twenty, and their sockets twenty, of copper; the hooks of the pillars and their bands shall be of silver.
(12) And for the width of the courtyard to the western side, there shall be hangings of fifty cubits, their pillars ten and their sockets ten.

So there were twenty poles each on the north and south sides, which Rashi defines as the entire side. There were ten poles for the curtains of the west side, but there were not ten poles to the west side itself, because together with the end-poles of the north and south sides, the west side had twelve poles. In other words, the poles in the northwest and southwest corners were attributed to the north and south, not the west.
So with only twenty poles, you have nineteen spaces, which should come out to   about five and a quarter amos to each space. So how could Rashi possibly say there were five amos?
I believe the simple answer is that when Rashi says there was a pole every five amos, he means approximately every five amos. On the north and south side the space would have been a little more to distribute the five amos over nineteen spaces. On the west side, the space would have been a little less to distribute fifty amos over eleven spaces. On the west side, it is exactly five amos per space (15 amos for three spaces), using the end posts of the north and south sides respectively.

The mishkan and the fencepost problem


ArcGIS - Convert a Shapefile into JSON with coordinates

Question: I have a shapefile and I would like to convert in ESRI Json with ArcGIS toolbox From feature to JSON.
When i convert it I visualize x and y values in meters while I want latitude and longitude information.
How can I set this option to visualize geo coordinates in json file?
Comment: So, you have a shapefile that is defined in projected coordinate system (meters as units) and when you convert it to JSON you get meters as well, but you want to have JSON coordinates defined in a geographic coordinate system (decimal degrees)?
Comment: Yes, my shapefile is defined in this way: PROJCS["WGS_1984_UTM_Zone_32N",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",9.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]] I want a json file with geo coordinates.
Answer: Some of the geoprocessing tools in ArcGIS respect output coordinate system environment setting, but not this one.
You need to run the Project tool beforehand creating a projected shapefile first (use the WGS 1984 GCS). This will create a new shapefile on the disk with coordinates defined in lat/long.
Comment: I' ve launched the script as indicated in [Project Tool]( http://resources.arcgis.com/en/help/main/10.2/index.html#/Project/00170000007m000000/) but I receive following error Runtime error
Traceback (most recent call last):
  File "", line 1, in
  File "c:\program files (x86)\arcgis\desktop10.3\arcpy\arcpy\arcobjects\mixins.py", line 949, in __init__
    self._arc_object.createFromFile(item)
RuntimeError: ERROR 999999: Errore durante l'esecuzione della funzione.
Comment: You may need to define the proper transformation.
Comment: I' ve defined the transformation as follow:WGS 1984 UTM Zone 32N.  I've executed this script and I correctly generate a new shapefile. What is the next step to obtain the json file with coordinates?
Comment: You run the same GP tool as you did, Features to JSON. Because you have your features in geographic coordinate system, the geometry coordinates will be exported with decimal degrees.
Comment: I've used GP tool Features to JSON but the result is the same. Results are  in meters. Where's the error?
Comment: Make sure the feature class (shapefile) you got from the Project tool has geographic coordinate system. This can be tested by creating a new map document and ArcMap and adding it into the map. Check the Layers (data frame) coordinate system and report it here.
Answer: I've resolved this proble following procedure at this link.
How to convert coordinates from meters to decimal degrees?
Comment: Yes! I've used QGIS to obtain a new shape file with coordinates in degree and then I've converted it in ArcGIS using FeatureToJSON toolbox.
Comment: So you used QGis?


What is the maximum password length in Subversion?

Question: If I am storing the Subversion user names and passwords for repository access in a text file in the conf folder, what is the maximum length of the passwords I can use? That is to say, how long can the secrets in the following file be?
[users]
harry = harryssecret
sally = sallyssecret

Answer: If you are using svnserve, it seems to be no limit defined (at least I couldn't find any mention of it). From svn book:

The svnserve server, by default, knows only how to send a CRAM-MD5 authentication challenge. In essence, the server sends a small amount of data to the client. The client uses the MD5 hash algorithm to create a fingerprint of the data and password combined, and then sends the fingerprint as a response. The server performs the same computation with the stored password to verify that the result is identical. At no point does the actual password travel over the network.

IMHO, if MD5 is used then you can use any manageable length for the password.
Answer: There's no limit in the config file (aside from memory constraints, of course!).
Whether the client limits the input or not will depend on which client you're using, of course, but I'd hope that all of them would allow fairly long passwords.


Preferred stocks vs common stocks and Goog vs Googl?

Question: I've read online and in the literature that apparently preferred stocks don't grow as much as common stocks. That makes sense, but Goog and Googl are closely tracking each other. I suppose Goog is technically considered as "common stock" but it neither has voting rights nor dividend payments. Can someone explain this situation to me? It doesn't make any sense.
Answer: Preferred stocks are income securities that  pay an annual dividend (usually quarterly but sometimes monthly or semi-annually) unless they are fixed/floating issues.  Most are issued at $25.  Most have no maturity date but they are callable at the issue price five years after the date of issue hence they 'don't grow' unless it's a convertible preferred.
GOOG and GOOGL are not preferred stocks and their correlation has nothing to do with preferred stocks.
Comment: Is it a hard concept to interpret Goog as basically a preferred stock?
Comment: Go to any of the web sites that list all existing US preferred stocks  and see if GOOGL is included in the list.  It's not.  What does that tell you?
Comment: It tells me that you didn't read the question. I know Goog is not a preferred stock, but you can interpret it as one like I've been saying.
Comment: You can interpret any planet that you see in a telescope as a star but none of them are stars.  Feel free to interpret GOOGL as whatever you want but it's not a preferred stock in the real world.
Comment: Well why is that? It doesn't have voting which i thought to be the main characteristic of preferred stocks. Not only that, it doesn't have any dividends either making it essentially worthless


Every ideal of an algebraic number field can be principal in a suitable finite extension field

Question: Let $K$ be an algebraic number field.
Let $I$ be a non-zero ideal of the ring of integers $\mathcal{O}_K$ in $K$.
By class field theory, there exists a finite extension(the Hilbert class field) $L$ of $K$ such that $I\mathcal{O}_L$ is principal. Can we prove this without using class field theory?
Comment: I noticed that someone serially upvoted for my questions and answers including this one.
While I appreciate them, I would like to point out that serial upvotes are automatically reversed by the system.
Answer: Okay, I don't know if you will be satisfied with this. But here is one way:
Let $I$ be a fractional ideal. Then by finiteness of ideal class group, there exists $m \in \mathbb{N}$ such that $I^m = (\alpha)$ for some $\alpha  \in K^*$. Let $L = K(a^{1/m})$. I claim that $I\mathcal{O}_L$ is principal. In fact, I claim that $I\mathcal{O}_L = (\alpha^{1/m})$.
Well, $(I\mathcal{O}_L)^m = I^m\mathcal{O}_L = (\alpha)\mathcal{O}_L = (\alpha)$. Clearly, $(\alpha^{1/m})^m = (\alpha)$. Now it is easy to see that if $I, J$ are fractional ideals such that $I^m = J^m$, then $I = J$. Thus, $I\mathcal{O}_L = (\alpha^{1/m})$.
Answer: Here is a nice generalisation of the result you ask for. We claim that there is a finite extension of $K$ such that every ideal of $\mathcal{O}_K$ is principal in $\mathcal{O}_L$.
Proof: Suppose that $|Cl_K| = n$ and write $[I_1],\ldots,[I_n]$ for the elements of $Cl_K$. For each $1 \leq k \leq n$ choose a representative $J_k \in [I_k]$. Also for each $k$ there exists an integer $m_k$ and an element $\alpha_k \in \mathcal{O}_K$ so that $J_k^{m_k} = (\alpha_k)$. By Rankeya's answer above, the ideals $J_1,\ldots,J_k$ all become principal in the ring of integers of
$$L = K(\sqrt[m_1]{\alpha_1},\ldots, \sqrt[m_n]{\alpha_n}).$$
It now remains to prove why for any ideal $I\subset\mathcal{O}_K$ with $I \simeq J_1$ say, $I$ also becomes principal in $\mathcal{O}_L$. If $I \simeq J_1$ then there is $x,y \in \mathcal{O}_K$ so that $xI = yJ_1$. Then
\begin{eqnarray*} x^{m_1}I^{m_1} &=& y^{m_1}J_1^{m_1}\\
&=& (y^{m_1}\alpha_1)
\end{eqnarray*}
and thus $xI\mathcal{O}_L = y\sqrt[m_1]{\alpha_1}\mathcal{O}_L$. Now there is a $z \in I\mathcal{O}_L$ so that $xz = y\sqrt[m_1]{\alpha_1}$. We claim that $I= (z)$. Clearly $(z) \subseteq I\mathcal{O}_L$. For the reverse inclusion take any $w \in I$. Then $xw = y\sqrt[m_1]{\alpha_1}v = xzv$ for some $v \in \mathcal{O}_L$. Since $\mathcal{O}_L$ is a domain this implies $zv = w$ and so $I \subseteq (z)$. Thus $I$ is principal in $\mathcal{O}_L$ which completes the problem.


Closure: Which academic subjects examine human reading?

Question: Can Which academic subjects examine human reading?. please be reopened? I've tried to edit it for clarity. Please LMK how else I can improve?
Comment: In general, we can't just reopen a question on request because a user would like it reopened. If there is a specific reason to do so, that should be explicitly mentioned in the question. (This is different from the other question you asked about, since that question is originally yours and was auto-deleted.)
Answer:
The question title and body still do not match. The question in the body seems very broad, opinion-based and possibly not within our scope.
The existing answer matches the titular question. It would be good if you could edit your question to match that answer. You can ask the question in the body separately, but I do not consider this a good question (see above).
You can cast reopen votes on your own questions pushing them to the reopen queue. There is no need to make a Meta post for this. This is what happened after your last edit. Three reviewers voted to leave the question closed in its current state.
What you can use Meta for is to debate the closure, but then you would have to bring arguments. Arguments (delivered in comments) may also help you to get your question reopened through the regular mechanism.


First fundamental form and angle between curves

Question: On surface, for which $$ds^2=du^2+dv^2$$
find the angle between lines $v=u$ and $v=-u$.This exercise is related to the first fundamental form. I think I need to find the angle between curves with parametrization: $$u(t)=t, v(t)=t$$ and $$u(s)=s, v(s)=-s$$ therefore $$du=dt, dv=dt$$ and $$du*=ds, dv*=-ds$$
Now I can make tangent vectors to both curves $$dr=\frac{dr}{du} dt + \frac{dr}{dv} dt$$ $$dr*=\frac{dr*}{du} ds - \frac{dr*}{dv} ds$$ Am I thinking right? Unfortunately at this point I don't have more ideas. For finding the angle I can use $$cos(a)=\frac{dr .dr*}{|dr| . |dr*|}$$ And then I could use the numbers "1", "0", "1" from the first fundamental form. But I'm absolutely unsure, so I would like to ask you about it. Thank you.
Comment: Do you know that we have always $ds^2=dr\cdot dr$?
Comment: No, where did you get this from?
Answer: You can parametrize your curves as $c_1(t)=(t,t)$ and $c_2(t)=(t,-t)$ (first coordinate: $u$). You are searching for the angle between the tangent vectors $v=(1,1)$ and $w=(1,-1)$ (tangent vectors along $c_1$ and $c_2$: note that they do not depend on $t$) using the metric $g=du^2+dv^2$ with components $g_{ij}(u,v)=\delta_{ij}$ for $i,j=1,2$.
Then the angle $\theta$ is s.t. $\cos\theta=\frac{\langle v,w\rangle}{\|v\| \|w\|}$,
with $\langle v,w\rangle=g_{ij}v_iw_j$ and $\|v\|=\sqrt{g_{ij}v_iv_j}$ (and similarly for $\|w\|$). We sum over repeated indices.
Comment: I am happy to read that! Bye, Avitus
Comment: I tried one more time to do it alone. After several tries and operating on $dt$, $ds$ etc. I've finally got a result. And now I've read your answer, which is much more easier to understand (in some points of mine result I didn't know what I was doing in fact) and got the same result, but took just a few minutes. Thank you!


Is it possible to work with 'marked positions' in IDA from idapython, and if so, how?

Question: I'm working on an IDA script in which I'd like to iterate through addresses that have been marked (with Alt-M).
Looking at the idapython documentation, it looks like maybe I can do this via the bookmark_t proxy class and related functions, but it's not clear to me how to make this work.  For example:
def find_index(*args) ‑> uint32
    find_index(e, ud) -> uint32
    e: lochist_entry_t const &
    ud: void *

e is obviously a lochist_entry_t, but I can't tell from the context what ud is supposed to represent, or how I would pass it as a void pointer to the call.  (For giggles, I tried to pass None in place of a NULL pointer, and it actually crashed ida.  Oops.)
I've searched the web for examples of using this api, but haven't found anything helpful.
Is what I'm trying to do possible? If so, can someone please provide a working example, or a reference/doc/blogpost somewhere that I missed, or even just a nudge the right direction?
Thanks in advance.
Edit:
Digging through more idapython documentation (in unrelated areas) leads me to believe that ud is user-defined context data, but it's not yet clear how to create this (since passing NULL/None seems to be a no-go) or pass it to the functions.
Edit 2:
Further research has led me to trying to use ctypes to create pointers to various data types, but even when using c_void_p to create a void pointer, I'm still getting a TypeError for the void* argument.
I also found some mention of using SWIG's cdata and similar functions, which would seem to make sense, since it appears idapython uses SWIG.  However, I can't seem to figure out what/how to import to get access to that in python.   Looking at various docs leads me to believe that those functions would be exposed via the SWIG interface definitions, and a quick look through the idapython SWIG interface definitions and the IDA SDK doesn't reveal anything I can actually import to give me access to those SWIG functions.
Edit 3:
I did manage to find uchar_array(size_t) which returns a character array pointer, so I tried to pass that to bookmark_t_size(e, ud) and again IDA crashed.  So at this point, I'm not sure what to try next.
Answer: To clarify, location history and marked positions are two different things...but it's not surprising that you wandered into that API and got stuck since that's the SWIG wrapper around the SDK itself and is hence not too user-friendly.
However, there's get_mark_comment and get_marked_pos over at https://www.hex-rays.com/products/ida/support/idapython_docs/ida_idc.html which is much easier and straightforward to use. Your mark limit is MAX_MARK_SLOT, so you can use this with those idc functions to iterate through all of the possible marks in the database.


Why are metals worse conductors when heated?

Question: When metals, (such as in circuits), are heated, their ability to conduct electric current is hampered. Why is this? Does the transition towards liquid disrupt a metal's ability to conduct, or is something else at play? I know as any material increases in temperature its atoms vibrate more, but I don't know how this affects conductivity. Thanks for your time!
Comment: Possible duplicate of: [If increasing applying energy to an atom excites electrons, why does electrical conductivity decrease as temperature increases?](http://physics.stackexchange.com/questions/233465/if-increasing-applying-energy-to-an-atom-excites-electrons-why-does-electrical)
Comment: It is always worth [doing the obvious search](http://physics.stackexchange.com/search?q=metal+conductivity+temperature) to see if your question has been asked before.
Answer: The hotter a material, the more its atoms or ions jiggle about and the harder it is for electrons to wriggle through, which translates into higher electrical resistance. Broadly speaking, the resistivity of most materials increases linearly with temperature (so if you increase the temperature by 10 degrees, the resistivity increases by a certain amount, and if you increase it by another 10 degrees, the resistivity rises by the same amount again). If you cool a material, you lower its resistivity—and if you cool it to an extremely low temperature, you can sometimes make the resistivity disappear altogether, in a phenomenon known as superconductivity.
Comment: Superconductivity is an entirely different phenomenon. It is explained by very different models. In fact, many good electrical conductors cannot superconduct (such as Copper).
Answer: Electrical conductivity is for the most part determined by electron-phonon(quantized lattice vibration) scattering. As temperature increases and the phonon amplitude increases, there are an increased amount of scattering events which result in decreased conductivity.


Validate a kerberos token with a keytab

Question: I'm using Java on the server side and I want to validate a kerberos ticket with java code.  I have a keytab file.  How do I do this?  I keep finding all of these samples which don't use a keytab but I believe I need to use this.  Also, I don't want to use spring or anything like that, just the GSSAPI.  I have a krb5.ini file as well.  Has anyone else done this?
Answer: I have done this. Take a look at the code of spnego.sourceforge.net. This is exactly what you need.
Answer: If you want to use SPNego, then the client also needs to SPNego. Most browsers and curl support SPNego.
If your client does not use SPNego, you can GSSP API Accept Security Context. For an example of how to use Keytab for accept security context, see http://docs.oracle.com/javase/1.5.0/docs/guide/security/jgss/tutorials/BasicClientServer.html#Progs

Validate a kerberos token with a keytab


MariaDB 5.5-56 not reading the my.cnf file and taking default values

Question: Permissions are correct. I actually went ahead and opened the file up to everyone (I know... big no-no but it's a closed off lab) any idea why MariaDB 5.5-56 wouldn't read the my.cnf file and just take default settings?
Comment: Can you provide any further information (error messages from the logs regarding reading the file)?
Answer: On a Linux OS, make sure the file <code>/etc/my.cnf</code> is owned by root.
Answer: I got it working. It was already owned by root but the permissions were a little off. I started thinking that I copied the file from production over to the lab and apparently some permissions were not carried over. Once I mimicked the old file permissions, everything started working. Thanks!


Does casting Beast Sense on a creature with truesight let you see as if you had truesight?

Question: In D&D 5th Edition, if you use the Beast Sense spell on a creature with truesight, do you see as if you had truesight?
Comment: Very related: "[Do I still retain my own vision type while seeing through my familiar's eyes?](https://rpg.stackexchange.com/questions/143009)"
Answer: It doesn't matter; there are no beasts with truesight
The spell beast sense (PHB, p. 217) says:

You touch a willing beast. For the duration of the spell, you can use your action to see through the beast's eyes and hear what it hears, and continue to do so until you use your action to return to your normal senses.

As you can see, the spell specifies that you cast the spell on a beast, meaning a creature with the beast type.
As it stands, there are no officially released creature of type beast with truesight.
But what if there were?
If, let's say, your DM had homebrewed a creature that was a beast that did have truesight; this would work in the same way as a beast with darkvision.
Since you "see through the beast's eyes", you would gain the benefits of its senses, since you're using its senses to see. So, in answer to your question, yes, you would then effectively get to use their truesight whilst seeing though their eyes.
My take on this matches up with the consensus of this related question: Do I still retain my own vision type while seeing through my familiar's eyes? (thanks to Medix2 for finding that question, see the comment under the question).
Comment: @soxroxr because Truesight is a supernatural sense, any official creature that has it would almost certainly be classified as a Monstrosity, not a Beast (which is reserved for natural creatures). Which basically means it's restricted to homebrew only. (The Beast type not having any special, encounter breaking abilities is one of the reasons it's much more easy to shapechange into one, or have other effects like this, that would become way more powerful if it'd work on supernatural beings.)
Comment: @Erik At least one (rather excessive) way of getting a beast truesight is through the [*true seeing*](https://www.dndbeyond.com/spells/true-seeing) spell
Comment: I think you should move the part about no beasts having truesight to the bottom. OP asked the question because they wanted to know the answer, clearly they have in some way encountered it. Telling them that it is unlikely to happen is at best a footnote.
Comment: There are currently no beasts which have truesight, but not only could they exist in the future, homebrew (as you mentioned) is to be considered, and the answer to the question is applicable in many additional scenarios such as with find familiar which is not restricted to beasts.

I wondered since truesight is more of a supernatural thing while darkvision is fairly natural.
Comment: @soxroxr Yes, there could be beasts with truesight in the future, which is why I wanted to add the second half of my answer (it would feel somewhat incomplete otherwise, like I've essentially dodged answering the question). Truesight does have more of a supernatural feel, I agree, but it's still considered a sense (_Monster Manual_, p. 9), and therefore seeing through the beast's eyes would still let you have the benefits of that or any other senses.


Retrieving folders and subfolders of an ExactTarget Content Builder with SOAP

Question: Is there any way to get the Content Builder folder and subfolder structure? And also want fetch asset from these folders.
Answer: These will each need to be individual calls.
For example, you can get assets easily via any of the retrieve/get asset in the Content Builder REST API
Simple filter: /asset/v1/content/assets?$filter=Category%20eq%20{{yourcategoryId}}
For Category/SubCategory (folders) you will need to do an individual call on each folder.
For example (lets say you have the sub category (4 directories down) where the asset lives, but you want the breadcrumbs to the root folder. You would need to do 4 API calls.
For example:
/asset/v1/content/categories?$pagesize=20&$filter=Id eq 3916
and you would then collect the ParentId from that call and make another call on that down to the root folder. You can collect name from each of these calls as well to have a more user friendly breadcrumb path - I just would not recommend filtering the API call on name, as there could be duplicates.


Mean lower low water (MLLW) for tidal correction

Question: I am estimating water depth (bathymetry) using satellite data over a US water. I have obtained tidal values (datum is MLLW) as at the time of satellite overpass to correct my satellite-derived bathymetry for tide. I was wondering if the value obtained (e.g. 0.68m) will be subtracted or added to my SDB estimates - to account for tide.
Answer: Good question as sign conventions can often trip up when dealing with water depths.

Water depths are generally considered as positive down.
Tide heights are generally considered as positive up.

Given your instantaneous water depth from SDB (positive down), and the tide height above MLLW datum (positive up), then to perform the tidal correction to attain depth w.r.t. MLLW chart datum:
<code>charted depth = SDB_depth - tide_height
              = SDB_depth - 0.68
</code>
Assuming that at the time of the SDB depth observation the tide is 0.68m above MLLW.


What is the underlying difference between motion compensation and motion estimation?

Question: I know that motion estimation has to do with calculating motion vectors, but where does motion compensation come into play. Can't we just do it with motion vectors, since, we are still calculating the differences in the displacement of the blocks in the reference and the target frames.
Answer: Motion compensation is the use of the motion estimation information to achieve compression.  If you can describe the motion, then you only have to describe the changes that occur after compensating for that motion.
I used this article as a primer.  Basically the first involves how you determine what movement is happening and the other is then used to determine what information changed after the movement and to describe what changes need to occur for playback.
Answer: My understanding of their differences:
Motion Estimation:

It is to generate the motion vector(s).
It's in the encoder only, since decoder only consumes the motion vector data.

Motion Compensation:

It's using existing motion vector(s) information, along with the reference image(s), to generate a predicted microblock. (The predicted block will be added to the residue block to generate a decoded microblock.)

This generation step can be a simple x/y translation of the single reference block. But it could be more complex when dealing with multiple reference frames/blocks or field based coding.
For example, in H.264, you can have two MVs with different weight, thus the compensation step to generate a predicted block would be like PB = w1*RB1 + w2*RB2.

It's in the decoder. But since there's a mini-decoder in the encoder. So the encoder has this component as well.

This page on MOTION ESTIMATION AND COMPENSATION provides more detailed information. Also looking at their location in an encoder diagram might also be helpful.


Does anyone have experience taking a kombi from Johannesburg to Mbabane?

Question: I'll be arriving in the Johannesburg airport and I've been told to take a kombi from there to [somewhere where they have kombis to Swaziland] and then from there to Mbabane. Does anybody have experience with this?
Answer: Not kombi vans exactly, but Go Swaziland offers comfortable-looking minibus transport from Johannesburg direct to Mbabane, meaning you won't have to figure out how to change in the middle in some other town. They'll also stay with you through the border crossing.
They have several pick up points available, including JNB airport
Comment: I've seen those, they're double the price of kombi vans apparently (for good reason I'm sure though). I'm currently seeing if there's anybody who can attest to the kombi van trip from Johannesburg to Mbabane. Specifically, how easy (or hard) it is and how safe (or unsafe) it is.
Comment: Fair enough, I'll keep looking as well
Answer: There was a kombi from the airport to Swaziland (Mbabane and Manzini) for 400 rand


I have bitcoins on my smart phone. How can I see and use my bitcoins on e.g. my pc?

Question: Or can I only use it from my phone? I downloaded and installed bitcoin core. took a day to get up to date. But wallet? Balance is zero. How do or must I log in? How does it work anyway?
Answer: In general, each wallet has its own set of addresses and private key chain. There is no way to log into your Bitcoin wallet, as there is no central service that is providing it to you, rather it is just locally stored on your device.
I would not recommend trying to share the same set of keys between different wallets, as it would increase the attack vectors on your money.
Rather, you might want to just send most of your bitcoins to whichever storage you expect to be most secure, and hold a spending amount on the other devices.
If you just want to see the coins on other devices, you may look up the specific address on a blockchain explorer such as blockchain.info, or read up on "watch only wallet".