Can we just throw a satellite in to mars orbit with a very high spin?

Question: I am thinking about this scenario of throwing a satellite to Mars orbit with a high spin, Can we just throw that? one hypothesis can be that high-frequency spinning generates apparent gravity so it might have enough mass to follow mars' orbit and reach it without using any energy but If anyone has his own expertise on this so it will be great!!
Comment: "high-frequency spinning generates apparent gravity" only for someone or something standing on the inside, in the rotating frame of the spacecraft, but that doesn't have any impact on the real gravitational forces from other bodies.  "...and reach it without using any energy..." We can't change gravitational potential energy without using any energy.
Comment: I am having a hard time understanding what this is saying but I am pretty sure that it's impossible. Spinning does not cause gravity.
Comment: The answer to all questions like this is no. The basic conservation laws (energy, momentum...) can't be gotten around. We can spin something and make it lighter so that it's easier to launch.
Comment: Can you explain it in more simple words by applying a mathematical approach as well?
Comment: You are saying that conservation laws can't be proved by doing this?
Answer: Your question isn't clear but I think I understand what you're after:
Put your satellite at the end of a rope, spin it around and release it when it's moving at the right velocity.  There are a couple of problems with this:

Unless your rope is exceedingly long you are going to subject your satellite to tremendous accelerations.

Of what is your rope made?  You're getting pretty close to the limits of material science by the time you have reasonable acceleration and throwing it to Mars.

Note that I am assuming your rope is already in orbit.  Throwing it from the surface of the Earth introduces a bunch more problems:

As michael_goulish points out, keeping your satellite from burning is decidedly non-trivial.  This makes the Galileo probe that was dropped into Jupiter look easy by comparison--and half that probe was a heat shield.

The acceleration it's going to take while being spun up is incredible--far, far beyond the hundreds of g's it will take as drag slows it in the lower atmosphere.

I don't think we have anything we can build it out of but I'm not certain.

And even if there is we currently do not know how to build something to survive the shockwaves that will be created by it's passage through the atmosphere while being spun up--the launcher will be destroyed.

As for a consolation prize:  I have actually proposed a different form of spin launcher:
No rope, it's built around the lunar equator.  There's no need for super strength because you can counter the forces by simply piling mass on top of the launcher and letting the moon's gravity keep it from flying apart.  No brutal atmosphere effects, either.  5g in the launcher gives you an ejection velocity anywhere from sundiving to interstellar escape--obviously, if you don't need that radical a trajectory you can launch with less acceleration.
Megaengineering on a scale mankind has never done but all the basic technology already exists--you'll need some R&D to build linear motors and maglev systems for that environment but there's no reason to think it won't scale up.
Comment: Possibly worth mentioning that for a orbiting platform conservation of momentum still applies so any boost this way is not free, the launch platform will be slowed and need to expend fuel in some form to maintain orbit.
Comment: @GremlinWranger It needs to do something to maintain orbit but you can do it with something like an ion engine, or you can do it in reverse--put a catapult on the moon, toss rocks, let your spinner catch them and deorbit them.
Comment: @LorenPechtel I am not considering any Physical attachment with my Sattelite, Assume that I spin my satellite without using any rope and throw it towards Mars orbit. Can it enter the orbit of Mars?
Comment: @JunaidIhsan I don't understand at all.  If the satellite is simply spinning it's not going to go anywhere.  The whole point of a spin launcher is to hold it in place building up speed until you let go--it lets you avoid taking your powerplant with you.  (Or let it move out along a cable that's spinning at a fixed rate.)
Comment: does letting it go from the correct height of an orbital elevator count?
Comment: @JCRM We can't build the cable for that.  **If** you could build a maximum-length cable it would work for interstellar to inside Mercury's orbit, not quite the range that my lunar design would do.  We can't even build a counterweighted cable, though.
Answer: How about if we just try it for low Earth orbit at first?  If we can't do that, we definitely can't get it to Mars.
OK, orbital velocity for low Earth orbit is about 7 km/sec.
But if you are going to hurl something into orbit, it will have to start out with a lot more velocity than 7 km/sec, because it's going to lose a lot on the way up.
So now you have a spacecraft shooting out of your spinlaunch facility doing maybe 9 or 10 km/sec right down here in the nice thick air.
It will burn like a torch and make a beautiful bright streak up toward outer space.
But not all the way up, I think.


How Audio steganography is called secure?

Question: Everyone can extract the information from audio file then how its called secure. Means if we hide the text message into an audio file its the possibility that the third person can extract then how its secure?
What is the security over sharing internet using this technique? Anyone can explain?
Comment: Please add sources who claims that this is secure and under what conditions. I could imagine that it is only claimed to be secure if the message is not just hidden but additionally encrypted which is the case with many steganography tools.
Comment: First question question you need to ask is if steganography considered secure at all? Hiding a message is not securing it.
Answer: Steganography is an Obfuscation technique. It doesn't offer any sort of confidentiality to the data unless an additional encryption is used. The above said is true irrespective of what kind of file you try to embed your data.
Secure usage of steganography is when you use encryption along with it.  Suppose you are trying to hide message M in file F.
Step 1: Encrypt message M. C = E(M)
Step 2: Use the Least significant bit of each byte of the file F to store the following - C and Details of Encryption Algorithm
Comment: Why should i add details of encryption algorithm ? If i want something to be secure i shouldn't give you those informations. The party i want to send it to will know the algorithm but noone else should. Am i missing something here ?
Comment: @ShinobiUltra I'd suggest you read this: https://en.m.wikipedia.org/wiki/Kerckhoffs%27s_principle


Is y at the end of muddy derivational

Question: Mud is the root word. If I add -dy to make the word muddy, is that suffix a derivational or inflectional morpheme?
Comment: That's a 'derivational morpheme' because it does change the part of speech of the word. 'Mud' is a noun and 'muddy' is an adjective. (BTW, the suffix is *-y*, not *-ddy*.)
Comment: Right. It's derivational. Here's [a handout on the subject](http://www.umich.edu/~jlawler/Inflection.pdf).
Answer: The suffix in the word muddy is -y, which is an adjective-forming suffix usually added to nouns and verbs. The root word in muddy is mud.
'Inflectional morphemes' are ones that don't change the part of speech of a word, for instance, the plural suffix -s or the past tense marker -ed:

bag → bags (both are nouns)
want → wants, wanted (all of them are verbs)

'Derivational morphemes' on the other hand are ones that do change the part of speech of a word. For example, suffixes like -y, -ise/-ize etc:

mud (noun) → muddy (adj)
standard (noun or adj) → standardise (verb)
Comment: See also _slime, slimy; haste, hasty; fish, fishy; health, healthy,_ ...

Is y at the end of muddy derivational


How to build a TM which decides $L_k := \{(\langle M \rangle ,x)\in HP : |(\langle M \rangle ,x)| \le k \}$

Question: For a specific natural $k$ we define the language of couples $(\langle M \rangle, x)$ such that $M$ stops on $x$ and the couple's encoding is bounded by $k$ i.e $L_k := \{(\langle M \rangle ,x)\in HP : |(\langle M \rangle ,x)| \le k \}$
This language is finite thus in $R$. I wish to understand how to build (Not formally) a TM, $\tilde{M}$ which decide this language. Since the only given information is that the encoding is bounded, I tried to think about "Pigeonhole" claim, i.e define $\tilde{M}$ which simulate $M$ computation on $x$ and remembering the configurations made by $M$ or by counting steps made by $M$ during the simulation in order to determine that $M$ is stuck in a loop. Since $M$ is deterministic, if $\tilde{M}$ "see" the same configuration twice, it guarantees that $M$ entered a loop, but I can't explain why the finite encoding of $(\langle M \rangle,x)$ promises that a configuration will repeat itself.
Answer: You cannot construct an explicit algorithm/TM which will decide the language $L_k$. Regarding your attempt at the proof: you are right that there is no guarantee that the configuration will repeat because these machines are not given to be space bounded.
The TM $M_k$ to decide $L_k$ will have all the tuples (which are finite in number) which are accepted hard coded in it. The TM will basically perform a search in a look up table: if that tuple is found then accept it, else reject.
We don't care how these tuples are actually obtained.
We can perhaps even prove that a general method to construct such TM $M_k$ for each $L_k$ cannot exists: Suppse there exists, then for a given input $<M,x>$, find the length of input, let it be $k$ and construct the TM $M_k$. Simulate $M_k$ over $<M,x>$. This will act as a decider for Halting Problem: which we know is undecidable. Hence, the assumption that we can have such a method is false.


How does FormsAuthentication.RedirectFromLoginPage() work?

Question: It doesn't return a view. In fact, the Action still needs to return a view after calling this ... so what's going on?
Answer: If you want to use the FormsAuthentication system, you'll want to switch to this line (which implicitly uses the returnUrl parameter).
return Redirect(FormsAuthentication.GetRedirectUrl(model.UserName, true));

You will get the URL that FormsAuthentication.RedirectFromLoginPage would have used, but you will explicitly bail from the action method with a RedirectResult instead.
Note
If you go this route, you'll want to put a defaultUrl parameter in the forms auth web.config line in case someone goes directly to your login page (or they pass in a redirectUrl that doesn't pass FormsAuthentication's security restrictions). Without overriding the default, bad URLs will be redirected to ~/default.aspx. In most MVC apps, that will likely 404.
<forms loginUrl="~/Account/LogOn" defaultUrl="~/" timeout="2880">

Alternative
If you spin up a new MVC 3 sample "Internet Application", you will find a LogOn action method that handles a returnUrl similar to what FormsAuthentication.RedirectFromLoginPage does internally.
if (Url.IsLocalUrl(returnUrl) && returnUrl.Length > 1 && returnUrl.StartsWith("/")
    && !returnUrl.StartsWith("//") && !returnUrl.StartsWith("/\\")) {
    return Redirect(returnUrl);
}
else {
    return RedirectToAction("Index", "Home");
}

Answer: It's exactly what it says - a redirect. This is a response code sent to the browser to ask it to request another URL. That's the point at which a view is requested in MVC, or a web page in straight ASP.NET.
Comment: But what about the Action's return value? If the call to Redirect creates a redirect, what do I display in the meantime? A "redirect, please wait" page? Hmm, that makes sense.
Comment: Shouldn't the **server** send a Redirect response? I have the same problem and I don't want to return a View, just the redirect response from the server.


What evolutionary driver could produce life that are animated only by light?

Question: Imagine an alien world populated by silicon based lifeforms, the mega fauna can only be animated by exposure to adequate lights from the star or the moon. This world concept is inspired by a automatronic killer giant doll in a mega hit Korean TV series, so I design all the creatures to only become animated when it receives sufficient energy from the electromagnetic radiation at specific threshold but I couldn't come up with a sound evolution driver that this mechanic can triumph over our familiar metabolic system where energy comes from food we ingested and excess is stored as fat. I am not sure why nature would prefer it this way over cat and mouse aka survival of the fittest where species evolve certain traits to aid them to eat others or to avoid being eaten, is my species doomed to extinction if they never adopt metabolic lifestyle?
Comment: Why would they be animated if not to hunt? What would they hunt for if not minerals that they need to repair themselves/reproduce? What better prey than others who've accumulated those materials - resulting in "vegetarians" - i.e. those who mine minerals, and "meat eaters" those who do the hunting. Could you tell us why this reasoning doesn't apply? Are they all plant-like, the only movement being to track the sun perhaps?
Answer: Creatures that become alive only with enough sunlight basically describes any deciduous plant. When winter and its short and cloudy days come, being alive becomes a liability. Better wait for summer and its long sunny days.
Independently from being carbon or silicon based.
Comment: You don't actually want to be dead, you want to have a zero-energy hibernation state.
Answer: Junk Yard Dogs:
Light is the basis of the food chain, whether it is chemically stored first or directly used. That would need to be some fairly intense light, or the organisms would move slowly in the dark and increasingly faster in the light. Usually, light is not a very dense form of energy in most places (but it could be - imagine organisms living on something like Mercury, although that brings it's own problems).
A biochemically-driven species on your planet would die, because the biochemical system depends on biochemical energy in it's food sources. There would simply be nothing to eat. Energy in your system isn't biochemical. It would be like a person trying to eat a car. But a car (even a solar-powered one) can move, and takes lots of energy to build, as do the parts that go into it. So parts form the basis of your food chain.
If animated species (read "herbivores") depended on difficult to manufacture/energetically costly components (like solar collectors) from passive species (read "plants"), then they would still be supplied by solar energy, but need to move so they could take advantage of resources. Species (read "predators") that obtained components from the richer, motive sources (the herbivores) would hunt.
Perhaps optical storage systems that store light and gradually absorb it slowly would give some species a competitive advantage. The "Waste" of the light in such a battery would actually be the absorbance of the energy over time. This way, a species could have a "light capacitor" that would prevent them from being immobilized the moment they went into a shadow (which suggests interesting hunting techniques...)
Mirrors would be extremely critical parts of species, so they could shelter in the dark or concentrate light onto absorptive surfaces while still obtaining energy. If the light is hot and intense, organisms may need to limit their exposure so components are not damaged by long-term overheating or radiation. Mirrors and reflective surfaces could be protective, as well.
So while energy is still the basis of the food chain, it comes from the increasingly predatory species operating with higher efficiency and sophistication due to the increasing concentration of quality components and taking advantage of the "lesser" species. The energy of "plants" is stored in components, not chemical batteries.
Answer: Crystal radio creatures.

https://en.wikipedia.org/wiki/Crystal_radio

A crystal radio receiver, also called a crystal set, is a simple radio
receiver, popular in the early days of radio. It uses only the power
of the received radio signal to produce sound, needing no external
power. It is named for its most important component, a crystal
detector, originally made from a piece of crystalline mineral such as
galena.1

Your creatures live on a world where chemistry does not lend itself to oxidation / reduction types of life.  But there is ample radio energy from their star.  The creatures are in essence crystal radios.  We oxidize reduced carbon and use the resulting energy to make electrical signals and contractions so that we might dance the merry jigs we dance.  Crystal radios (and silicon carbide is an acceptable crystal for this) turn radio energy into electrical current.  The depicted set produces enough energy from radio waves to power the headphones attached.  I have seen a crystal radio that powered an LED.  Your creatures use radio energy turned into electrical energy to power their activities.
There would, it seems to me, still be evolutionary benefit in being able to store energy so your crystal creatures could dance their merry jigs at night.  It also seems to me there would be benefit in animals not needing to sleep so we could dance our merry jigs all night.  Yet all animals sleep.  So too your crystal beasts.  They are up when the sun is up, jigging their crystal selves around with radio wave power.  When the sun goes down they fall asleep.
Answer: You are basically describing plants, but with two twists:

those beings move
those beings don't store energy

Plants usually don't move, because it takes a huge amount of energy and sunlight doesn't provide a lot of energy density. So during the winter they turn on power save mode instead of migrating.
If your planet is exposed to intense sunlight (giving plants enough energy to move) and a very slow day/night cycle with super frosty nights, it might cause plants to move to keep tracking the sun. But then again, with these circumstances the current day side will probably be incredibly hot and will kill all living things there. So maybe the plants will chase the twilight zone of the planet?
Regarding the energy storage point: It would be a huge disadvantage for a creature not to be able to store energy, since walking into shadow would be equal to death. That's not really advantageous.
Answer: A planet with a very long day/night cycle
Basically, this is a planet where each day or night is an entire season.
On Earth, it is normal for plants to shut down in the winter, which creates a chain reaction through the entire food chain - many animals either migrate, hibernate, or in the case of many insects simply die off and leave their eggs to re-awaken in the spring.
But plants and animals on Earth can't simply use the presence or absence of light to trigger these behavioral changes, since day and night still happen in both the summer and winter. They use a complex system of recognizing when the days are shortening and the temperature getting colder to determine when it is time to enter the winter-phase behavior. In addition, there are evergreen plants that can survive the cold, so some animals might still stay awake - food is more scarce in the winter, but not completely absent.
On a planet where day and night are essentially seasons, the difference between summer and winter would be even more extreme - there would be no "evergreens" adapted to resist the cold, because there's no sunlight anyway. During the night, all plants would hibernate or die, and all animals would need to do one or the other (unless they could migrate around the entire planet every cycle).  For hibernators, the process could be triggered simply by the absence of light, because day and night define the "seasons", rather than merely being altered by them.


Stop animation Canvas pod in Swift

Question: So I have installed Canvas pods to animate quick and easy. I have added some animations, but the animations play instantly when the view is presented. How can I stop that initial animation so it will only play when the AnimationTest.startCanvasAnimation() is called?
Answer: At first, I set type as empty.
And when it is needed, set code:
<code>AnimationTest.type = "shake"
</code>
E.g.
<code>@IBAction func Pressed(sender: AnyObject) {
AnimationTest.type = "shake"
AnimationTest.startCanvasAnimation()}
</code>
Answer: It's explained in the CSAnimationView.h
<code>    @property (nonatomic) BOOL pauseAnimationOnAwake;  // If set, animation wont starts on awakeFromNib
</code>
So, you have to insert on more key in the User Defined Runtime Attribute under Indentity Inspector. You will have this:
type, duration, delay and the last one is pauseAnimationOnAwake with is Boolean and set to true.
Thats it!

Stop animation Canvas pod in Swift


Difference between a controller (e.g PD) and a compensator(e.g Lead)?

Question: Really.What is it?Can't find anything anywhere related to it...Please don't give fancy examples.Just tell me the difference
Comment: I wouldn't be too concerned with semantics. 'Compensator' tends to be used for a sub-system that aims to improve one measurable aspect of a system, eg the phase margin. 'Controller' tends to be used more generically, and may seek to adjust a number of design criteria, eg steady state gain and overshoot.
Comment: What is a (e.g Lead) compensator, what is it used for, where did you see it mentioned?
Answer: In simply words:
Regulator (controller) is a device that controls the object in closed loop on the basis of difference (error of regulation) between measurements of object's output and external steering signal, regulator tries to reduce error to zero.
Compensator only change object characteristics (transfer function), e.g. phase of output signal. Compensators are used in connection with regulators, in feedback loop (change characteristics of object's output signal) or in steering path (change steering signal from controller to object).
More here: https://en.wikibooks.org/wiki/Control_Systems/Controllers_and_Compensators


Can I use PayPal for non-US iTunes Store payments?

Question: Can I use PayPal for non-US iTunes Store payments?
I've heard US users can do so, but my PayPal and iTunes account are non-US
Answer: Payment methods vary greatly among the many iTunes stores around the world and are often fit to the local market. In Germany, for example, it's possible to pay via direct-debit, because this is a very common way to pay there. There are iTunes stores (additionally to the US one) which accept PayPal - UK comes to mind. In your case I would check my iTunes account to see whether it is possible to pay via PayPal.
Comment: thanks! actually, I've found that debit cards are accepted in my local store, so there is no need of paypal for me
Answer: One way to pay in foreign stores is to buy gift vouchers (i.e. on ebay) and open a second account with a fake address and use these vouchers.


What is this strange light in photo?

Question: I found a picture from my camera archive 2012, which I need explanation about. It looks like either something happened to the camera or a certain light was captured.
Comment: Possible duplicate of [Mysterious signs or easily explainable artifacts?](https://photo.stackexchange.com/questions/99778/mysterious-signs-or-easily-explainable-artifacts)
Comment: I redacted the email address for quick damage control. Not a good idea to post personal email addresses in cleartext here, you'll get drowned in spam.
Comment: Visiting Angel left a feather behind?
Comment: "raw" would only be relevant if this artifact (probably perfectly ordinary lens flare)  was invisible or notably different in the jpeg or tiff file.
Answer: It looks like a caustic, a shape that is produced by refraction of bright light at curved surfaces, most prominently when curved in more than one axis. Glasses filled with a clear liquid frequently show such effects, but even an empty drinking glass or bowl can do so.
To me it does not look like a lens flare at all. Most importantly you can see the shape conform to the recesses in the wall or ceiling.
Addendum: It might be produced by reflection from a strongly curved surface as well.
Answer: This looks like flare from the lens. This happen when the light source is close to the angle of view of your lens.

Lens flare refers to a phenomenon wherein light is scattered or flared
  in a lens system, often in response to a bright light, producing a
  sometimes undesirable artifact within the image. This happens through
  light scattered by the imaging mechanism itself, for example through
  internal reflection and scattering from material imperfections in the
  lens. Lenses with large numbers of elements such as zooms tend to
  exhibit greater lens flare, as they contain a relatively large number
  of interfaces at which internal scattering may occur. These mechanisms
  differ from the focused image generation mechanism, which depends on
  rays from the refraction of light from the subject itself.
Flare manifests itself in two ways: as visible artifacts, and as a
  haze across the image. The haze makes the image look "washed out" by
  reducing contrast and color saturation (adding light to dark image
  regions, and adding white to saturated regions, reducing their
  saturation). Visible artifacts, usually in the shape of the lens iris,
  are formed when light follows a pathway through the lens that contains
  one or more reflections from the lens surfaces.

From the observation of @xenoid it can be also caused by water drop on the front element of lens.
Comment: It could also be that the flare is being projected onto the wall from another source and that is why the photo was taken (capturing an interesting effect) - I don't see much of a reason to photograph the wall otherwise, but then again, I wasn't there...
Comment: Lines look a bit distorted, as if the light was some drop of water.
Comment: @xenoid, interesting, it can be also reflection from water drop on the front element of lens. Will add it in the answer :)

What is this strange light in photo?


Can I run a receptacle from a GFCI in the bathroom to another room?

Question: Can I run a receptacle  from a gfci  in the bathroom to another room?
Is this allowed? I know it would work, just looking to see if this falls under the electrical code?
Comment: AFIK the current NEC prohibits this. A GFCI protected  receptacle in a bathroom cannot be on a circuit with receptacles not in that bathroom or in other bathrooms. However, the lights and exhaust fan can be on a circuit with lights or receptacles in rooms other than a bathroom.
Answer: The bathroom needs its own circuit, the only current code compliant way to go to another room if it is also a bathroom. Added per @harpers comment. If the bathroom loads include the fan and light then another bathroom can not be powered from this circuit. I like bathroom lighting to be separate because if the wife or girls plug in a curling iron and use a hair dryer at the same time it may trip the circuit and put them in the dark.
Comment: True, though also...If the circuit powers bathroom non-receptacle loads (lamp, fan) then it cannot power receptacles in other bathrooms.
Comment: This is correct I will add that.+


How do I view negative reviews for a podcast in the iTunes store?

Question: How do I read negative reviews for a podcast in the iTunes store? It looks like they are censoring reviews. I myself wrote a negative review but I don't see it showing up.
Answer: Not all reviews get posted and sometimes the delay is days or weeks for some reviews to show. I believe the stars get updates much more rapidly as a human doesn't need to review those ratings like Apple does for the word portions of reviews.
This is similar to app reviews:

Is there a standard delay for consumer ratings of apps on the App Store?
Why do iPhone App Store ratings and reviews seem to get processed so slowly?

I believe if you put star ratings in and feel they aren't updating, a request to the iTunes store support team might help unstick a podcast with problems updating. https://www.apple.com/support/itunes/contact/ and choose Store Support.


Manga where the main character was cursed with only understanding hostile creases and massively decreased exp

Question: The manga starts with a whole school class being reincarnated and a goddess shows up in front of the heroes explaining everything until the main character said he didn't wanna do it and wanted to go home.  She opened up a portal and he got sent to a forest where he found out he was cursed with only understanding hostile creases and massively decreased exp.
Comment: Probably a dupe of this question: [Manga where the main character is tricked by a goddess and given the 'curse of the hero'](https://scifi.stackexchange.com/a/266124/20774)
Comment: Ah, "creases" is probably "creatures" as per your answer.
Answer: Is this Is This Hero for Real?...?

When a goddess transports Hansoo Kang and his classmates to a magical fantasy world to become heroes, it's like a dream come true. But when Hansoo declines to risk his life for a world that isn't his own, the goddess leaves him for dead, alone in the forest. That's when he realizes she's not what she seems. With the help of a loner god, Hansoo faces the hostile new world and earns powerful blessings to help him survive. But his goal isn't to save the world; it's to return home… well, after he gets revenge on the goddess that is.

The Korean protagonist, Hansoo Kang, and his classmates are transported to the fantasy world of Fantasia by a goddess and told that they'll all become heroes and be blessed with powers to enable them to defeat the Demon King threatening this world. Hansoo Kang's classmates are apparently fine with this, but he asks the goddess to send him home, as he doesn't believe that someone who worries about his family can save the world.
She opens a portal for him, but when he steps through it, he finds himself in a forest surrounded by vicious beastmen, instead of being back on Earth. After being pursued by these beastmen for a while, he manages to open up a status screen, which reveals that he's a '[Curse] Hero' with a skill that automatically translates the languages of hostile races for him, but who'll receive a greatly decreased amount of experience from hunting and quests.
You can read the full manhwa at Tapas.


Choose approach for external Jenkins orchestration

Question: I wondering if there is a solution for external Jenkins orchestration or not?
Let me explain our setup first:

We have several huge Java artifacts which needs to be tested through continuous integration pipeline
A job is configured to grab a code after commit, run unit tests and build an artifact itself
B jobs (there is 4 of them for now) run different set of smoke tests in parallel using empty databases. They triggered only after A job succeeded. Those jobs use external resources: cloud nodes (to which artifact will be deployed) and databases from DB pool. Jobs can return three statuses in Jenkins:

green: cloud node was obtained successfully, artifact was deployed, all tests passed
yellow: there is no infrastructure failures detected but some (or all) tests failed --> Blame developers/QA here
red: there was one one more infrastructure failure: cloud messed up, database unavailable, artifact deployment failed. --> Blame DevOps here

C job: run only if all of B jobs were green. Otherwise end of flow. Uploading an artifact to Nexus
D jobs: run functional tests: several jobs here will reuse cloud nodes from B jobs to save time for deployment. We don't care which status they will get: green, yellow or red. Just record results and that's it. However, there are two jobs here which will deploy original artifact from A job in clustered configuration and if deployment succeeded then E job start independently (i.e. if D1 job fail, than E1 shouldn't start but if D2 job succeeded in the same workflow, than E2 should be triggered).

When workflow is finished, you need to determine a status: if there was a fatal error (any red build) than workflow must have a failed status.
After workflow if finished, all resources must be freed up: cloud nodes and databases.
Which workflow/process flow tool or library can I utilize to implement such logic?
We have several other pipelines with different flows so it should be flexible.
Current implementation have very complicated logic and several technical jobs which will take care of shared resources. We want to implement that logic in single place: an orchestrator which will be triggering Jenkins jobs externally, feeding them with parameters to run.
Answer: Checkout the Rundeck plugin for jenkins.
Rundeck is an SSH based orchestration tool.


topologies of spaces in escher games

Question: There have been a couple of games released (or in development) in the past couple of years which do some weird topological tricks: Echochrome (video), Crush (video), and Fez (video). Do the spaces portrayed in these games correspond to known sorts of topological structures?
Comment: If "asteroids" was what I think it was, it lived on a torus. "Pacman", on the other hand lived on a cylinder.
Comment: Bonus points for anyone who can describe the topology of [Portal](http://en.wikipedia.org/wiki/Portal_%28video_game%29).
Comment: Back when echochrome first came out, I showed it to a fellow grad student (one of the best in our year) who exclaimed "Wow, that's some good projective geometry!".  Now, I don't know any projective geometry, so I don't know if that's the right notion, but it's a good place to start looking.
Comment: "asteroids" anyone?  (i believe its $RP^2$, but i havent played for many years...)
Comment: [Related...](http://math.stackexchange.com/questions/10741)
Comment: From video and I've seen, it seems that Fez rotates the 3D world and then projects it onto 2D, and that's all.
Answer: The main focus of these games is not weird topological structures so much as weird transformations of the space.
In Echochrome, the "rotation" transformation connects points (via holes) that were not connected before, and undoes some connections. At any instant, the Echochrome space can be viewed as some sort of minor topological quotient of $\mathbb{R}^2$, but derived via rules from some underlying 3D space (with a quotient?).
In Crush, the space is 3-dimensional, but the crush action is like a projection onto 2-d space. The space in Crush isn't really notable, but what is notable is that uncrush followed by crush doesn't always yield the same 2d-world. The issue is that the camera can be in the middle of the 3-d world in crush, instead of far away.
I admit I haven't played Fez, but I imagine some combination of the Crush and Echochrome comments would cover it.

topologies of spaces in escher games


Am I eligible for Home mortgage interest deduction if I live outside the US?

Question: I am a US citizen living outside the US, and I have a mortgage.  Am I eligible for Home mortgage interest deduction?
Answer: The definition of residence qualifying for the interest exemption is in Sec. 121 (the interest deduction itself is discussed in Sec. 163). From my reading of that section, there's nothing to prevent you from taking the deduction.
Keep in mind that since you're not going to be having 1098s from your foreign bank, you'll need to provide proper documentation of the interest paid throughout the year, and also handle the currency conversions.
There's also a discussion on how currency fluctuations affect your mortgage treatment for tax purposes. Some people claim that if the total principle paid in US Dollars is less than the original loan in US Dollars when you pay off the mortgage, the difference (in US Dollars) is considered income to you, even if in your home currency you paid off the loan in full. I disagree with this interpretation, but I'm not a licensed tax professional. Talk to one.
Comment: I'm confused--Section 121 is for sale/conversion/etc of home as far as I can tell, not the deduction of mortgage interest. I think a better reference is [Publication 936](https://www.irs.gov/publications/p936/ar02.html) which says that unless you use the home at least part of the year, you can't take the deduction.
Comment: @mkennedy As I said, the section that deals with the deduction is Sec. 163, but it refers to Sec. 121 with regards to the definition of "primary residence".


1993 Ford F350 stalling when braking and when put in gear

Question: I have a 1993 Ford F350 automatic non-diesel T-tag dump truck that is mainly used on a 25 acre cemetery. It's rarely driven over 5mph and only has about 1000 miles put on it yearly. But when I leave the property for errands or to get fuel and it goes over 5mph sometimes it stalls when I brake. It happened yesterday. I had to stop due to oncoming traffic and it started stalling and making a gear grinding sound, I was able to give it some gas to keep it from stalling and made it to the store. After shopping, I started it and put it in OD, it stalled when I touched the gas pedal. I thought maybe it is a gear issue so I started it in D2 and it stalled again. The third time I put it in D1 and I didn't have a problem. Of course trying to drive 35mph in D1 was difficult so I switched to D2 but felt like it had less power when I would give it gas. I think it is a 5.8L.
Answer: Well, there's a few things here:

doing mostly short low-speed trips (at the cemetery) qualifies as "severe service." You will need fluid changes more often than you think.
the truck only driving properly in 1st gear (D1) could indicate very low fluid in the automatic transmission. Check the transmission dipstick for both level, colour and smell. (pink-red smelling sweet is healthy, brown-red smelling burnt needs a change)
unexpected stalling on an automatic is usually an indication of poor fuel delivery, poor air delivery, poor compression or poor spark.

Poor Air Delivery:

inspect your air filter and change if needed
inspect your mass airflow meter and clean it if necessary
make sure your mass airflow meter is connected securely and there's no corrosion on the connector
inspect your idle air control valve (and the hose coming from it), clean it (and the hose) if needed
make sure your idle air control valve is connected securely and there isn't any corrosion at the connector

Poor fuel delivery:

inspect your fuel filter and replace if necessary
measure your fuel pressure
perform electrical tests on your fuel injectors
make sure your injectors are connected securely and there isn't any corrosion on the connectors

Poor compression:

perform a compression test

Poor spark:

inspect your spark plugs and replace if necessary
inspect your spark plug cables, measure the resistance and replace if necessary
make sure your spark plug cables are connected securely at both ends
inspect your distributor cap and rotor, replace if necessary

Some of the items above (fuel filter, air filter, spark plugs, distributor cap and distributor rotor) last about 2 years on a normally driven vehicle. With the low annual mileage and low speeds you are putting on your vehicle, these figures don't apply, but they are still components you need to replace regularly.


Is there some way to mark which branch is the latest in subversion?

Question: We're reworking our process with subversion at the moment, and one of the things we're doing is making branches for each release target in our demo environment so that you can test a release that has been delayed independent of code that will be released separately. I am also experimenting with Jenkins in order to automatically run and report out on our unit tests in our demo environment. Is there some way in subversion to say "This branch is the release we're testing at the moment" such that Jenkins will check out that branch to test it? If not, how should I be approaching this issue?
Comment: How about committing a symlink to the latest branch under a consistent name?
Answer: This is a CI issue, not a SCM one. In Jenkins I assume you have a set of jobs that are looking at a particular SVN URL (eg trunk). You can edit these to point to a different url such as the current tag, or you can create a new set that mirror the trunk jobs but have a different repo url. Jenkins lets you group these in views to keep the display neat. You will also want to change the working copy of these jobs so it can checkout both sets simultaneously.
I use the 'job copy' feature in Jenkins to create a set of jobs from templates. You can set a variable in the template that is expanded at copy time to replace the svn URL and other parameters to keep the jobs separate.
Comment: Yeah, but we use a frequent branch strategy, meaning I have to go clone the job every week or so. I was looking for a hands-off approach.
Comment: You can script modification of the SVN urls, create new jo9bs based on a set of templates, or look into plugins like [FeatureBranchNotifier](https://wiki.jenkins-ci.org/display/JENKINS/Feature+Branch+Notifier+Plugin) but I think that only works with Mercurial currently.
Comment: @Yamikuronue There are plugins and tools (such as https://pythonhosted.org/jenkins-autojobs/ and http://entagen.github.io/jenkins-build-per-branch/ ) which can help automate some of that process.
Answer: There doesn't seem to be. But Bamboo, which we're upgrading to from Jenkins, will automatically build and deploy a branch (any branch it finds) when it has activity. Set it up to do a clean deploy and you automatically have the tests run on the one that has activity, which by definition is the one we're testing currently.


Flux/Alt Basic async example throws "Cannot dispatch in the middle of a dispatch"

Question: I'm struggling to get around the Cannot dispatch in the middle of a dispatch error Flux is throwing at me, with a basic example.
On my view, I've got a button which triggers a socialLogin(token) action, on my AuthActions. With Alt on my Action, I generateActions('login');
My socialLogin method performs an Async API request which returns a promise (Api is a simple class using a request lib):
// AuthActions
socialLogin(type, access_token) {
    Api.request('get', 'auth/social', { type, access_token })
       .then((payload) => {
           if (payload.code !== 'OK') {
               // Do something...
           } else {
               this.actions.login(payload.data.token);
           }
       })
       .catch((response) => {
           console.log('ERROR', response);
           // Do something....
       });
    this.dispatch();
}

The Store onLogin method currently does nothing.
However running this throws/catches the error Uncaught (in promise) Error: Invariant Violation: Dispatch.dispatch(...): Cannot dispatch in the middle of a dispatch.(…).
I cannot understand why, after reading many issues/articles - shouldn't the this.dispatch() "resolve" the current action being dispatched?
How would I go about triggering some other action here, or even trigger multiple actions (login, use another external action etc).
Thanks!
Answer: I think in your example you can just omit the this.dispatch(); line entirely, and it should. The action creator function socialLogin is called as part of a dispatch itself, so it is not allowed to call dispatch. If you do want to dispatch a socialLogin action at the start of the login process (e.g. to allow putting up a spinner or something), you could return the payload you want to dispatch. e.g. replace this.dispatch(); with
return { type, access_token };

That way stores can listen to socialLogin if they want to catch the start of the process.
Answer: what you need is this.actions.myAnotherAction(), where myAnotherAction is another action within the AuthActions in your case. Look
Answer: inside the action, just return a promise like:
 socialLogin(type, access_token) {
  return (dispatch) => {
    dispatch({type:type, accessToken:access_token});
    return new Promise((resolve,reject)=>{
      Api.request('get', 'auth/social', { type, access_token })
      .then((payload) => {
       if (payload.code !== 'OK') {
           // Do something...
       } else {
           this.actions.login(payload.data.token);
       }
       resolve(payload);
       })
       .catch((response) => {
       console.log('ERROR', response);
       // Do something....
       reject(response);
       });
    }
  }

}

Also sometimes in the container/controller views, you might be calling actions as a result of this action which will lead to the same error. In that just call any subsequent acction with defer option in dispatch like:
  myaction.actionname.defer(options);


Server hosting on Comcast - Would they do anything for a small server?

Question: I'm setting up a web server for a small business, and the only ISPs in our area are Comcast (15MBPS upstream) and Qwest (90KBPS upstream). Qwest seems completely unbearable as a choice for server hosting, but they have no clause in their Acceptable Use Policy or Terms of Service barring businesses from hosting websites. Comcast however; strictly forbids it. The owner of the business wants to go ahead with hosting on Comcast, however; I informed him of the small detail in the AUP. He didn't seem concerned about it, because he thought this policy was only enforced when Comcast received complaints about illicit content, or we exceed the 250GB bandwidth quota. I was less convinced. The problem is, Comcast seems to be the only option to server hosting, unless we outsource to another company, and lose direct access to the server, the operating system, and our privacy. What should I recommend? Should I advise him to take the risk and host on Comcast, or simply avoid setting up a website in the first place. We aren't expecting the site to suddenly get a whole bunch of traffic.
Comment: "We outsorce to another company, and lose direct access to the server, the operating system, and our privacy" This is absolutely incorrect. You might not have personal access to the server, but every decent hosting provider will have 'remote hands' who can do any physical work required. And you can get full root/admin access to the OS to do everything you could do if it's local. Infact, I'd go as far as to say it would be less secure being hosted on a private network. Most DCs have 24/7 security, CCTV, logged/keycard access etc.
Comment: Look for a provider that does PCI certification on servers, PCI means the servers, datacenter and staff have been examined and the security of the service confirmed. When it comes down to it 99% of security is down to software, not physical location
Answer: Why not host the website somewhere else? Why do you HAVE to host onsite? I recommend you use a VPS or some other hosted service. Those bandwidth choices are really terrible and I doubt you'll be able to maintain any kind of reasonable uptime.
Comment: There are also plenty of hosting providers that give you access to the OS. If you're Linux savvy Linode is quite excellent.
Comment: So rent space at a co-location facility and put your hardware there.
Comment: We need very good security that simply can't be insured by outsourcing (and potentially not even knowing what COUNTRY we're going to be hosted in), and the owner of the company insists on hosting on-site and refuses to use an off-site hosting service. Also; we don't need a HUGE amount of bandwidth, as we're a very small business and are not expecting a tremendous number of hits.
Comment: Linode looks like a good service, but unfortunately the owner doesn't want to outsource hosting unless Comcast cancels his service.
Answer: You're looking at residential connections. Remember, you can often get Comcast business internet with a better service level agreement and different terms of service.
Personally, there's nothing wrong with getting an unmanaged dedicated server or VPS somewhere remote via a respectable web hosting company.
Comment: Can you get Comcast Business for a small-business operated from a residential area?
Comment: I've heard mixed reports of people both able and not able to get Comcast business internet in a residential area. I'm actually going to give it a shot the next time I move, but your best bet is contacting a Comcast rep and seeing if it's available.
Answer: We do some hosting on our inhouse comcast circuit, nothing mission critical or anything, and haven't had any complaint from CC. I'd have to re-read the contract but I don't remember reading anything that would prevent us from hosting client facing services, web or otherwise.
That being said I'd reevaluate your position on "outsourcing". A VPS will only cost you the loss of worrying about server hardware, you'd maintain everything else you listed as a "loss".
Answer: I host some servers on a ComCast 'business' connection, mostly just a public VPN server for employees to remote in for dev. work, and clients to check out what we've got in dev. for them.  The service itself is alright, although not fantastic.  If I were trying to make money off of it, the story might be different.
One serious problem, though, is that the 'business' class router ComCast provides (an SMC unit) is just garbage.  It's extremely locked down to what you can do and access with it.  For example, they lock down SNMP, which leaves you unable to monitor your own device!  As a business, I have a problem with that.  Also, the public facing server is actually a Heartbeat cluster, or is supposed to be --the SMC router doesn't play well with the ARP stuff that goes on to enable failover, and so instead of having a hot standby, I have a cold standby.  I have to leave the second machine off.  Kinda defeats the purpose of a cluster...There may be other ways around it, but for any sane router, I shouldn't have to figure it out/work around the router.
Also, even ComCast business support is terrible --they walk you through the same 'troubleshooting' steps as they do for a residential connection.  Turn it off, turn it back on, blah blah blah.  Nevermind that that is totally unfit for a business situation, especially if you're trying to host a server!  In my particular case, it turned out to be their DNS servers were down, which I tried to convince them of with some basic networking, to no avail.  I actually told them about it before they knew their DNS was down...
So, I don't know, it's a mixed bag.  If this is supposed to generate revenue for you, go to a reliable hosting provider.  If security is an issue, host your own box.  I've seen a lot of places doing 1u colo's for $50/u/month, which is less than the cost of the ComCast business connection.
Comment: but can you bridge the business router, or simply forward all the ports to one local IP (another router)? that'd remove any LAN problems it causes. I've also seen claims people were able to get their own modems working.


Exempt an application from redshift?

Question: I'd like to use redshift on Ubuntu to redshift all but some whitelisted set of applications, e.g. Emacs, which I've configured to look the way I want already.  Is this possible?  If so, how do I specify the applications?
Answer: I don't think so, the only thing I saw was that you can start it with ...
redshift

(with some options) and disable it with ...
pkill -USR1 redshift

That seem to indicate there are no config options for enabling/disabling it per started software and that redshift works on a system wide base. The sample configuration does not have anything on it either. Something you might be able to work with: you can enable/disable it per viewport. Maybe you should group the software you do not want to use it with and make them open on viewport 2, and have redshift not do viewport 2.
So when you do
pkill -USR1 redshift && emacs

emacs would start without it and you would have to manually restart redshift. But putting that in front of any software you want it to start without seems a bit much.

Exempt an application from redshift?


Ros Humble Camera Deep Learning

Question: I want to depict a Model in 3d which is basically a rectanglular piece of Weld in Ros Humble Gazebo and Rviz. Could you give some suggestions on which camera do i need to us? Do i need a Depth Camera or a combination of Depth Camera and RGB camera?
Answer: Based on the scope of your application, certain cameras can provide depth data tailored to the specific range you're interested in. Not sure about all the details of your project, but maybe check out the Intel RealSense D435? I've found it's pretty solid and a lot of folks use it. It's kinda the go-to for both virtual and real-world stuff.
https://github.com/IntelRealSense/realsense-ros
Comment: ok Thanks a lot. I will look  into it.
Comment: The Goal of the Project is bring a 3d Object from the Real world and perform a Image detection with the Help of a Deep Learning Model, which i plan on training. The Robot should move to certain location after it identifies some set of features  depending on the image to move there.
Comment: Well it is hard answer without a specific question. In my experience, if you are going to run a real-time inference with a deep learning model with camera it really depends on the model that you are using. It seems you are in the preliminary phase of the project, so my recommendation is to get familiar with the relasense camera, compile it with GPU support, and play around the ros2 topics it provides(check github link). There is one topic that gives you the depth aligned with the RGB image which you can subscribe to and use the bounding box coordinate from the deep learning model.

Ros Humble Camera Deep Learning


Where can I get a mystery box?

Question: Where can I find a mystery box in Pokémon Go? I saw the news about the upcoming event involving shiny Meltan and want one, but I don't have a mystery box.
Answer: You can't just find that box in PoGo, you need to trade with a Pokémon Let's Go account to get it. If you don't have it and don't know anyone who does either, you'll be able to get a single Meltan from the Special Study I imagine - I haven't completed it myself, but like other Special Studies (Mew, etc.) it should provide you with one Pokémon to catch and a bunch of Candy. Since Meltan requires 400 Candy to evolve though, it's going to be a pain to evolve it without the Mystery Box.
Comment: When you transfer Pokemon to Let's Go you get the mystery box which can only be open once a week and works like a lucky egg that spawns Meltan around you current location for 30 minutes only for you.  The special research provides one Meltan and 5 extra candies.
Comment: 5? Damn that's stingy, I think it was 20 for the two other studies.
Answer: With the release of Pokémon Go and Pokémon Home integration, you can receive a Mystery Box by transferring Pokémon into your Pokémon Home storage. This requires you to connect your Pokémon Go account with a Nintendo Account.
Linking Accounts

Click on the Pokéball icon and go to settings on the top-right of the screen
Scroll to the bottom and click "Pokémon Home"
Follow the on-screen sign-on options to sign into your Nintendo account

Transferring Pokémon

Click on the Pokéball icon and go to settings on the top-right of the screen
Scroll to the bottom and click "Pokémon Home"
Click "Send Pokemon", and then follow the on-screen steps to transfer your Pokémon into Pokémon Home.

After you transfer Pokémon over to Pokémon Home, you will receive a Mystery Box.

Where can I get a mystery box?


Mouse wheel events not fired when focus on map element INSIDE winform web browser

Question: i'm displaying a openlayers map inside a winform web browser,
since i'm getting focused on map element(with a click on the map), i have not getting mouse wheel events any more,even not document mousewheel event, to start getting the events again i need to click on some other element rather than a map element.
when the app is running outside of the web browser(in IE,chrome,Firefox) everything working fine.
Has anyone seen a similar problem?
Comment: Yes, countless times, for countless reasons. Most likely you have a Javascript error somewhere. Without a minimum working example, it is likely to be rather hard to diagnose.
Comment: As i said, everything working fine in a browser, the problem is **winform web browser**. i have no errors.
Answer: This is because losing focus on the map inside winform.  You can use yourBrowserControl.Document.Focus() to re-focus on the map after any of your c# actions and you will get your mouse wheel control back.
In my case, I used splitContainer to split the screen and I used the following code which works out great.  Every time when I click on the map, it will gain the focus back to the map, then the mouse wheel will work.
// add event hander
this.splitContainerMain.Panel2.Enter += new System.EventHandler(this.splitContainerMain_Panel2_Enter);

// handler method
private void splitContainerMain_Panel2_Enter(object sender, EventArgs e){
    if (webBrowserMap.Document != null)
    webBrowserMap.Document.Focus();
}


call to web api endpoint from same mvc application is timing out

Question: I have a REST service implemented using ASP.NEt Web API. For some reasons I needed to call one of the endpoints from within the same application and report the time it took to get a response from the endpoint. For this added an normal MVC controller with an action as below
public class HealthMonitoringController : Controller
{
    //
    // GET: /HealthMonitoring/

    public ContentResult GetResponseTime(string id)
    {
        var startDateTime = DateTime.Now;
        var httpWebRequest = (HttpWebRequest) WebRequest.Create(<<REST endpoint>>);
        httpWebRequest.Method = WebRequestMethods.Http.Get;
        httpWebRequest.Accept = "application/json;charset=utf-8";
        httpWebRequest.Headers.Add("Accept-Language", "en-GB");
        httpWebRequest.GetResponse();
        var duration = (int) DateTime.Now.Subtract(startDateTime).TotalMilliseconds;
        return Content(String.Format("response time:{0}", duration.ToString(CultureInfo.InvariantCulture)));
    }
}

As you can see above, I'm using a HttpWebRequest class to invoke the REST endpoint hosted in the same website. I record the time before and after the request is made and return that time.
Problem
We have got a monitoring tool which calls on this route to get the recorded response time. The monitoring tool calls this route every 1 minute. This usually works for some time and then httpWebRequest.GetResponse() starts timing out for no obvious reason.There is nothing in the event log and in the IIS logs
At the point if I restart the application pool, this thing start working again for some time and then stops after some time.
While the above thing is not working, if I make the REST endpoint call myself manually, it works. So there is no issue with the REST endpoint.
I'm completely clueless at this point. Any help would be much appreciated.
Answer: First off, a "health check" from the same domain is pretty irrelevant; and checking latency this way is especially trivial. Understanding you have problems and looking for a way to track this issue, use a trace log or elmah, not a repetitive ping to the endpoint.
That being said, if you want to check if the API is working you can instantiate the controller and call the method directly. This would test the access portion without layering the issue with potential socket trouble (WebRequest/WebClient/* libraries). Though you're not really getting in to delay, as I mentioned, delay is useless in this context anyways.
var api = new ApiController();
try {
  api.SomeMethod("param1", "param2");
  return Content("works");
} catch (Exception ex) {
  return Content("failed: " + ex.Message);
}


Use AJAX to watch SQL database for changes

Question: I have a column in my database that will be updated randomly. Whenever that column is updated I need to refresh content on my page. How can I use AJAX + jQuery to perform an action only on DB changes?
Answer: What you are describing is colloquially called Comet programming.  Comet describes a group of techniques for pushing content to a web page with a persistent HTTP connection.
The push would be initiated using a trigger/stored procedure combination in the database server.  That way, it occurs no matter where the data update comes from.
Comment: for example http://www.ape-project.org/
Comment: You got it.  Wikipedia (http://en.wikipedia.org/wiki/Comet_%28programming%29): Comet ... is known by several other names, including Ajax Push, Reverse Ajax, Two-way-web, HTTP Streaming, and HTTP server push among others.
Comment: This sounds very nice. I will have to look into it. Thanks for the advice!
Answer: The server (database/web) can't initiate a connection--only the client can.  So you will have to poll the database until there is an update.  You can create a web service that checks the database and which jQuery uses.
Edit: I stand corrected.  It is possible to keep an AJAX connection open until the server "pushes" data to it.  See: http://en.wikipedia.org/wiki/Reverse_Ajax
And apparently it really is polling:  http://en.wikipedia.org/wiki/Push_technology#Long_polling.  If the server doesn't have any data to send yet, it keeps the connection open until it does.  It's not "pure" push technology, because the client doesn't have a listening port which the server connects to.  The effect is similar, however.
Edit 2: So back to answering your question...  You'll have to choose how to "poll" the web service.  The web service would then have to check the database to see if there were updates.  Checking the database for updates might be the trickiest and really depends on your requirements.  You can run a SQL query to see if anything changed, but how would you know?  You would need some sort of parameter (typically a date) to compare against.  If done wrong, you could miss some updates or have multiple hits for one update.  What Autocracy said would be a good way to get notified of updates.  You can keep that list in the database, in memory, etc. and clear it when the client gets the updates.
Answer: use setinterval function of javascript for polling and to check the value of the updated dababase field
check following link for more detail http://www.elated.com/articles/javascript-timers-with-settimeout-and-setinterval/
Answer: Im doing almost same thing with a chat, reloads a php script every xx sec.
Looks like this:
replace j with $ if not using jquery.noconflict..
<code>j(".chatref").everyTime(3000,function(i){
    j.ajax({
       url: "chatx.php",
       cache: false,
       success: function(updated){
           j(".chatref").html(updated);
           ...do stuff..
       }
   });
</code>
This is an very nice method i think :) if you want to send vars to chatx.php just add ?php &x=1&y=2?>
Answer: Hook a special stored procedure into your database that alerts your application after a modification. You'll need a custom module and the right trigger statements.
Your other option is polling.
Comment: How would it alert the application, which is on the client's browser?
Comment: The application is in two parts: on the browser and on the webserver. The backend web service is responsible for talking to the database unless the asker is using the .0000001% style of having the browser talk SQL to a database.
Comment: +1 for a way to prevent "database polling", even if doesn't prevent "client to server polling"
Answer: You will have to continually poll a page that has the value from the database.
Comment: @RobertHarvey Such as? can you give such?
Comment: Not necessarily.  There are push techniques available.
Answer: I'd suggest creating an HTML page that uses setIntreval() to repeatedly make AJAX calls to a PHP script that queries the your database.  You could use JSON and PEAR to make the task a little easier.
Reference Links:

http://www.w3schools.com/jsref/met_win_setinterval.asp
http://api.jquery.com/category/ajax/
http://api.jquery.com/jQuery.getJSON/
http://php.net/manual/en/function.json-encode.php
http://pear.php.net/manual/en/package.database.db-dataobject.php
Comment: Got it. Thanks a lot. Your method works perfectly! Just can't set the interval too low or there are problems with opening/closing data readers.
Answer: You will basically have to constantly poll the server for changes to the DB. The server cannot make a call to the client, so the client will just have to constantly ask the server if there have been changes.
Comment: See http://en.wikipedia.org/wiki/Reverse_Ajax


how to get polynomial equation from points

Question: How can i get polynomial equation from points?
I have data in excel and i want to get polynomial equation from it. I can get polynomial equation using excel using trendline but only to order of 6.
I would like to know how does excel get polynomial equation just with the points.  the graph and the equation is shown in the picture
graph
Comment: Do you knwo polynomial regression ?
Answer: As you said, if you are graphing the data points, then you can just select the polynomial order to be 6, and then tick the checkbox to say that you wish "display equation on chart". This is explained in detail here: "Excel best fit line curve function"
However, if you wish to obtain the equation of the polynomial via cell formulae and not as a chart feature, then you need to either leverage the less documented features of LINEST.
This is explained:

Does Excel have a function similar to LINEST, that fits a polynomial instead of a linear equation? If not, how can I accomplish this?,
"Quadratic and cubic regression in excel"
Answer: You can do this most easily with matrices, and  a quick Google search shows that matrix multiplication can be done in Excel, but it can be a bit of a pain, especially with so many points.
Let $A$ be the matrix created from the system of equations that result from plugging each point into $f(x)$ and $y$ be the matrix containing the values of $f(x)$. So given a set of points $\{(x_1, y_1),(x_2, y_2),...,(x_n, y_n)\}$, if you want a polynomial fit of degree $N$ (with $N>n$), you'd have the following matrices:
$A = \begin{bmatrix} x_1^{N} & x_1^{N-1} &  x_1^{N-2} & ... & 1 \\  x_2^{N} & x_2^{N-1} &  x_2^{N-2} & ... & 1 \\ \vdots & \vdots &  \vdots & \ddots & \vdots \\ x_n^{N} & x_n^{N-1} &  x_n^{N-2} & ... & 1 \end{bmatrix}$
$Y = \begin{bmatrix} y_1 \\ y_2 \\ \vdots \\ y_n \end{bmatrix}$
Now take set the matrix $\beta$ as
$$\beta = (A^T A)^{-1} A^T Y$$ whose elements are the coefficients of the $N$th degree polynomial corresponding to the set of points.


Is this sentence ambiguous or not?

Question:
To my way of thinking, the last sentence " The upsetting event could even be something as simple as sitting here right now, reading this book, feeling depressed, anxious, or discouraged." can be understood as a description of one upsetting event in which a person is experiencing three things(sitting, reading, and feeling at the same time), or understood as three separate events(e.g. Bob sitting here as event one, John reading a book as event two, Tailor feeling depressed as event three).
I am not a native English speaker. I am confused about which understanding is correct.
Could anybody tell me which understanding is correct and why?
Answer: The sentence is referring to one activity, with the body in a position, and with a feeling that the person is having while doing it.
The activity is reading. The position is "sitting" or "seated". (In England they would even say "you could be sat here".)
The feeling is one of these: depression, anxiety, or discouragement.
It may be tricky because of the list of feelings at the end of the sentence, but to me it is pretty clear that the sentence is meant to be understood as:
(Sitting here) and (reading) and (feeling [x or y or z])
Hope this helps!
Elie
Comment: Thanks for your help

Is this sentence ambiguous or not?


MicrosoftKeyboardHelper and MicrosoftMouseHelper

Question: I have neither a Microsoft Mouse nor a Microsoft Keyboard, nor any Microsoft software installed on my Mac.  Why then do I have MicrosoftKeyboardHelper and MicrosoftMouseHelper running in my process list?  Their parent process is launchd.
Comment: Hah! A google search for "MicrosoftKeyboardHelper" brings this up as the second result.
Answer: Could the computer have had a Microsoft keyboard or mouse connected at any time in the past?
If so the drivers may have been installed when the Microsoft KB & M were being used, and not uninstalled when the KB & M were removed.
You would probably be safe to uninstall the software/drivers if it is causing a problem.
Comment: I think I had plugged a Microsoft keyboard into my Mac years ago.  Now, I need to figure out where to uninstall them.
Comment: To be honest, im not terribly familiar with Macs, and thus do not completely understand how it handles drivers. As joshhunt mentioned, its worth a look in the Applications folder or Login Items folder for anything with a name similar to "MicrosoftKeyboardHelper". Also you could try AppDelete, its free and helps to remove any remanents of deleted files. AppDelete can be found here: http://reggie.ashworth.googlepages.com/appdelete
Answer: Inside your Applications folder, open the "Utilities" folder. There should be an "Intellipoint Uninstaller.app" there. Run that and it should remove the Helper Apps/processes. (Note that it will ask you to reboot at the end of the process.)
Comment: This worked for me.
Answer: You must have installed them at some point. You can either dig around for the files that launch them yourself, or you can run this and see if it catches them for you:
http://www.khiltd.com/Downloads/ConsultantsCanary.tar.gz
It won't actually remove anything, just point it out.
Answer: What an oddity. Do you have a 'Microsoft Keyboard.app' in Applications? It appears as if that is the source of these daemons. If that is present, try removing it. These also may be present in System Preferences > Users > [Your User] > Login Items
AFAICT, this program is a part of the IntelliType tools for OS X to enable extra functionality on certain keyboards. If you are certain that you have never used a Microsoft keyboard, it could be possible that you have used another keyboard with similar hardware and they have used used the same program to enable said functionality. Another possibility is that these have installed themselves as a part of other Microsoft software.


i form in 吐く息一つにも生命が宿り

Question: I've recently bought a Japanese scroll, for decoration, with a famous quote from The Last Samurai:

吐く息一つにも生命が宿り

But I think this is incorrect: in the film this was part of a speech, and there was another phrase after, so of course it finish in "り". But if I'm going write this as a single phrase shouldn't I end it in "る"? So it should be:

吐く息一つにも生命が宿る

Am I correct?
Answer: If this is a partial quote from a longer sentence, you should not try to alter it, anyway.
In addition, ending a sentence with an i-form (stem) or a te-form is not necessarily a mistake. Making a "partial" sentence and not saying everything is a not-so-uncommon technique in poetry/lyrics, and doing so can leave room for the imagination. For example, one could name a song as 聖なる夜に雪は降り instead of 聖なる夜に雪は降る; this is not very common, but the former can look more dramatic.
It happens also in casual speech. See でございまして in this sentence? and What exactly is this でね construction?
Answer: A phrase ending in <code>-i</code> (連用形) is an expression in its own right, not necessarily wrong. Of course, whether it is appropriate to use it in a certain situation is another question. Yes, it is "incomplete" as a sentence, but may not be "incomplete" in the way you think.
If you put it in English, it'd be like "life dwells in (each) a breath you breathe out, and", which would be felt quite truncated. But grammar-wise, it is merely another form in the verb's paradigm in Japanese, as if the difference between "I walk" and "I walked". Taking another example, A novel Brightness Falls from the Air by James Tiptree Jr. has a translated title 輝くもの天より堕ち, which is, by meaning, "brightness falls from the heavens, and", but grammatically comparable to "brightness's having fallen from the heavens" or "when brightness falls from the heavens". These English phrases are not "complete sentences" either, but are self-contained enough to be a title by themselves. It might sound like a brain twist because a piece of grammar, whose form is parallel to those English while carrying the Japanese meaning, is unavailable in English, but it is a basic device in Japanese.
Answer: Pre-masu form (stem form) can be used either to connect phrases (continuous) or to end a phrase/sentence (conclusive). While the latter usage is not found so often in contemporary Japanese, in phrases such as proverbs, holdouts from a more classical era have remained in the language. Changing the end to 宿る would not accurately reflect the origins and nuance of the phrase.
Looking up proverbs, you can find many that end with あり and other pre-masu forms.
終止形 (conclusive) and 連用形 (continuous) verbs are effectively the same, it is simply their usage that differentiates them.
*From movie:
'To know life in every breath.
Every cup of tea. Every life we take.
That is the way of the warrior.'

i form in 吐く息一つにも生命が宿り


How do I change my email address on Play Store as the one I have is no longer in use

Question: The email address I have on Play Store is no longer verified and I wish to change to my current provider as I do not seem to be able to download apps
Comment: What do you mean "change my provider"? Its not going to change the content you can get from the play store. Just get yourself a new email address and add that into __*settings>account>*__…youll have the choice of what email address to use when you enter the play store.………are you sure that is the reason why you can't download? Did you try clearing the data/cache? Search through Stack Exchange for "non-working play store" ( I'm not at my computer now, otherwise I'd provide a link for you).
Answer: Go to settings->accounts->add account->and add another Google account with the new email. Then go into the play store and there will be your email with a drop down arrow. Tap it and select the new email.
Comment: What Google page should I be on when I click "Settings>Account"...? Every (or nearly every) Google service has a "Settings" gear and probably a lot of them have some settings for "account". I tried this by going to play.google.com, then I clicked: "gear"->"settings". I don't see any place to add a new email address (or edit existing).


EIGRP Neighbor State

Question: I understand that OSPF has states that describe the status of a neighbor (e.g. Init and Full). Does EIGRP also have similar information? I'm programmatically trying to get the status of an EIGRP neighbor using SNMP OIDs. Is there anything in the MIB that can give me the information that I need?
Answer: EIGRP isn't nearly as involved as OSPF in establishing neighbor relationships.  Routers discover one another via periodic multicast (and sometimes unicast) hellos.  The hello is answered with an exchange of topology information and the adjacency is formed.  There's not really an equivalent of a DR election, EXSTART, etc..  You can pull information that might indicate a one-way communication (OutQ building up, null SRTT) but it's otherwise pretty on and off.
Apologies if you've already looked at it, but the EIGRP MIB has an EIGRP peer entry - check out 184.108.40.206.188.8.131.52.4126.96.36.199.1 (or browse it @ http://tools.cisco.com/Support/SNMP/do/BrowseOID.do)

EIGRP Neighbor State


How to quickly determine whether the intersection of two linear subspaces contain nonzero vectors?

Question: How to quickly determine whether the intersection of two linear subspaces contain nonzero vectors?
Please give a algorithm.
i.e., both $Ax=0$ and $Bx=0$ have nonzero solutions. where the vector x has the same dimension. We know that all the solutions to $Ax=0$ is a linear subspace $V_1$, and all the solutions to $Bx=0$ is a linear subspace $V_2$. It is known that the intersection of $V_1$ and $V_2$ is also a linear subspace, which is denoted by $V_3$.
Please give a method to determine that whether $V_3$ has a nonzero vector. Thank you!
Comment: What have you tried till now ?
Answer: Let $M$ be the matrix consisting of $A$ on top of $B$ (i.e. the rows of $A$, then the rows of $B$).  The condition is that the rank of $M$ is less than its number of columns.  Use row reduction to determine this.


In the Blade Films why is EDTA able to destroy La Magra but has no effect on Reapers or Jared Nomak?

Question: In the Blade films why is EDTA able to destroy La Magra but has no effect on Reapers or Jared Nomak?
Comment: From your comment it seems pretty clear that you're looking for a science-based answer to a fictional plot device (which makes the question off-topic)
Comment: I'm using the facts presented in the film itself.
Comment: @MCUAndYouFilmBlog the thing with film is that it's short. Not everything can be seen so a lot is reliant on real world logic and science.
Answer: That's because Eli Damaskinos, the creator of the reapers, genetically engineered them to be superior to vampires in every way. One of his focuses was the removal of all the weaknesses common vampires had.
It is never stated how exactly he removed/reduced each weakness (that would slow the pace of the movie down). (Perhaps a bone case around the heart, faster infection rate thanks to a barbed tongue, immunity to Silver and Garlic and increased resistance towards EDTA making it only stun/hurt them instead of killing them).
The explanation to how he was able to counter EDTA is that the events of Blade 2 take place two years after the first movie in which EDTA was used to pretty much kill a vampiric god. Knowing that such a weapon exists, Damaskinos would have made it a priority to counter it in his next generation of vampires. Admittedly two years is a short amount of time for such a mutation to occur, but Damaskinos did have a large pool of resources to work with including vampire scientists who required much less downtime than a human one would, and of course a long series of test subjects they just nabbed off the streets. The short duration they had to perfect their new breed might even be the reason why it still affects them to some degree.
Comment: Using blood from vampire test subjects who have no resistance to EDTA and Blade who also has no resistance to EDTA it resulted in new genetically modified reapers who are not affected by EDTA and are immune to its energetic(chemical) reaction?
Comment: @MCUAndYouFilmBlog we never know what happened to Karen Jenson, the serums creator after the first movie. She might have been picked up by vampires between the two movies and her secrets came to light. Also anticoagulant (the base of EDTA) is a common chemical substance related to blood... something vampires might have already been experimenting with for decades.
Answer: That was quite literally the point of the 'Reapers', genetically modified vampires without the weaknesses of normal vampires, created by splicing altered vampire DNA with Blade's own highly resistant 'daywalker' DNA
That being said, given the novelty of Blade's EDTA weapons, presumably resistance to it was a coincidence rather than something that was being intentionally aimed for.

BLADE: Keep talking, Stevens.  Tell me why.
STEVENS: (sputtering).
The Shadow Cabinet.  For decades they've
been trying to find a way to rid
themselves of their hereditary
weaknesses.  Viral epidemiology,
immunochemistry.  Recombinant DNA was
the next logical step.
NYSSA: (genuinely horrified).
No, that's not possible.  They wouldn't
keep something like this from me...
STEVENS:
Your father didn't want you to know.
(haltingly)
Something went wrong.  The Reaper strain
was too aggressive.  Then Nomak escaped.
Blade II - Original Script
Comment: Using blood from vampire test subjects who have no resistance to EDTA and Blade who also has no resistance to EDTA it resulted in new genetically modified reapers who are not affected by EDTA and are immune to its energetic(chemical) reaction?
Comment: You're asking how a fictional DNA treatment protected against a fictional weapon?


Move Add To Cart button to right sidebar

Question: We are just implementing a Magento store (migrating form OSCommerce) and are trying to move the Add To Cart button (for Simple, Grouped and Configurable products) to the right column sidebar - we have a three column layout.
We have been having very unpredictable results with moving the cart and/or options to the right column - total items wrong on add to basket, alerts to 'to add to basket' even though products have been added etc.
All attempts so far have resulted in broken add to cart functionality.  Has anyone else succeeded with this?
Thanks
Shaun
Answer: The Add to cart button is a submit button inside a form. Moving it out of the form into the right column will break it. You have two options:

Modify the template files so that the form encompasses the middle and right columns.
Have the button submit the main form via javascript.


Storing password to use later

Question: I have a deployment system with a user interface that is accessible over the Internet. I want to make it more secure by re rolling the password periodically over the API. Is there a safe way I can store the password locally on my computer? I'm worried about someone brute forcing the password on the publicly available interface.
Comment: Using the _change password_ form?
Comment: I'm going to do it directly over the REST API.
Comment: Ok, _using the change password REST API_. But, could you clarify where's the problem?
Comment: I want to access the password. I want to automate the whole process so I need to store the password for later use. I can't hash it because I need to use it for an environment variable in a service.
Comment: Is your computer presumed secure? It will depend on your threat model. If you are only worried about the publicly available interface, storage in local computer should be no issue.
Comment: Is there a best way to encrypt the password? I'd prefer not saving it in plain text. Ideally, I could use a password only I know as a key so I can re roll the public password automatically without exposing my private password to brute force. Does that make sense?
Answer: Well - you are asking for trouble here with your current setup. Why do you have a deployment interface exposed to the web?
You need to add

IP whitelisting or host internally and connect into the network securely
2FA using an authenticator - SMS is out these days
Store the salted hash not the password
Use PBKDF2 or bCrypt for the hashing. Look up current suggested iterations numbers and imimplementation
Answer: If you're the system's developer, that's an insecure model. The password should be salted and hashed at client side, then hashed again with a server-supplied nonce, and that hash checked on the server.
The client machine should also be checked before checking the password. If the IP isn't static, it can be done with certificates.
The user-entered password shouldn't be used as anything other than a password, not as a key (use a KDF), not as an environment variable, nor stored any longer than it takes to hash it. Other secrets should be irreversibly derived from it and other values.
If you're not the developer and have been forced into this model by an application, then it seems like you're just looking for a local storage password manager like LastPass.
Comment: The deployment system is open source so I'll have to dig into the auth system and make some modifications so I can get a one-time use token verified by a certificate. Will that improve the security of the system?
Comment: Depends on the implementation, but if done right it's more secure. And keeps plaintext passwords from being sent and stored. What is the password normally stored in an environment variable for, BTW?
Comment: The deployment system manages Docker containers, one of which needs to make changes to the other Docker containers. Are there any big gotchas I need to be aware of? Any articles you would suggest? Thanks for your help.

Storing password to use later


What determines the block's timestamp?

Question: As a miner, what happens if I propogate a block with a future timestamp, or yesterday's timestamp? What determines the block time? Can I just give any time here or is it okay to change it with 1-2 seconds?
Answer: The timestamp of a block must be higher than the median of the timestamps of the past 11 blocks. It also needs to be less than 2 hours in the future (wall clock) at the time of validation.
Note how a block invalid by the second rule can become valid eventually.
Comment: So what you are saying is there can be a recent block whose timestamp has a previous date than the latest block?
Comment: Yes, as long as its timestamp is higher than the median of the past 11 blocks.

What determines the block's timestamp?


Bicycle acts like it's braking when I walk it

Question: When I walk my bicycle, every few feet it stops like I've pulled the hand brake. It will roll some more then stop again. What do I need to do to fix it?
Comment: If you have rim brakes, are the brakes dragging on the  wheel rim? If you lift up the bike and spin the wheels, what happens?
Comment: There is a slight chance that the problem is a bad hub bearing, but most likely it's an out-of-true wheel causing the brakes to drag, as others suggest.  This is usually a simple fix, but it requires some mechanical smarts and a few tools, so best take it to a bike shop.
Comment: I bet it feels the same when you ride it too.
Answer: I'm assuming you have rim brakes.
Lift each wheel in turn off the ground and spin it. Does it appear to snake from side to side as it spins? If so, your wheel is out of true (it's no longer a disk but a sort of round Pringle) and it's catching against the brake pads at some part of its wobble.
If the wheels look OK when they're spinning, place the bike back on the ground and try to push the bike sideways by putting your foot against the axle. Does the wheel wobble against its mounting? If so, its bearings are bust.
Both of these are things that only an experienced bike mechanic would have the tools and skills to fix, so unless I've missed something, you're going to have to take it to a bike shop.
Answer: If it is an issue with the rim itself being misaligned this is something you could fix yourself if you feel confident. You need a tool called "Spoke key" or "Spoke wrench", which allows you to fasten, and unfasten the spokes. My city has a bike club (German ADFC) which offers a public workshop twice a week, where you could lend the tools (and get some advice). I did the same thing to my bike, and it was not too difficult. If you cannot lend, it costs about 10 Eur.
From the front, the wheel would look like this:

By slowly turning the wheel and watching the distances between rim and brake heads, find the area of the rim that is misaligned and touching the brakes
Put duct-tape markers where it starts, and where it ends
Spokes connect to the rim on both sides. Each spoke has fasteners close to the rim.
By fastening the spokes on either side you can force the rim to move slightly towards that side. Make sure to even out the force by fastening several nearby spokes, and also loosen the spokes on the other side just a little.
When done, turn the wheel and let (for example) a screwdriver hit the spokes halfway between hub and rim with approximately constant force. The contacts should all emit a similiarly pitched tone: If a spike pings higher it is too fastened, if it pings lower it is too lose. Both are bad, because it increases the stress individual spokes have to bear.
There is also a tool that allows to measure this more directly available if you can visit a workshop.
Do not fasten the spokes too much, they are meant to have some headroom to move if the wheel bumps.
Observe the distances beween rim and brake: The wheel should not wobble anymore. If there is still wobbling, repeat.

Unless the rim itself is damaged, this usually allows to correct the issue.
Disclaimer: Because it is really bad if your wheel breaks while you are riding, exercise caution after having done this repair. If you have any doubts about it, let an expert do it.
Comment: If it is a non-true rim, I'd not expect someone who didn't diagnose it themselves to get this right. Theres an old adage on spoke wrenches -- you may as well give them out for free cause people using them will make up for it in business (and then some).
Comment: What do you mean by non-true rim? I can only speak from my own experience here, and it was not particularly difficult to get right. I rode well above 500 km since then, so I assume I did not do any major mistakes.


Transferring digital PS3 games to PS4

Question: Is it possible to transfer digital games from PS3 to PS4? Like i was thinking of getting Destiny for PS3 till i get my PS4 but i don't know if it will transfer over or not. I've seen a lot of things say that you cant but i wanna make sure that it does or doesn't. So just reply back with a reasonable answer so i can chose which Gen. to get it for. I've heard from like a bunch of posts and websites that you cant but i just want the answer.
Comment: Are you asking if Destiny has crossbuy enabled or are you talking about something else? Destiny does not have crossbuy if that's what you are asking.
Answer: If a game is labelled as cross buy then depending on the game this could mean you buy it once and share it between the PS4 and PS3. Note that cross buy also includes the Vita so you could have a game for example where cross buy means you can play on the PS3 or Vita and not the PS4.
In the case of Destiny I believe there was a special time limited free upgrade option if you brought a PS4 within a certain timeframe (up until Jan 2015). This had nothing to do with cross buy though.
So for Destiny you should certainly purchase it for PS4 as the deal has expired.

Transferring digital PS3 games to PS4


How does Sovereignty over Airspace work?

Question: Usually people on international flights hear, Now we are in blah-blah airspace and so alcohol is permitted.
How do laws like these exist and how is the command or authority over airspace administered or exercised?
Comment: An interesting question, but pretty much answered by wikipedia: http://en.wikipedia.org/wiki/Airspace
Comment: I was hoping to get a defined answer, I looked at the Wiki Page. But it doesn't really satisfy.
Answer: The right of a country to administer the airspace over its territory is enshrined in international law.

Under the Convention on International Civil Aviation (the Chicago Convention), each State has complete and exclusive sovereignty over the airspace above its territory.

This means that when you are flying over a country, it is as if you were in that country, from a legal point of view. If the country prohibits the serving of alcohol, then an aircraft is breaking the law if it serves alcohol while in that country's airspace.
The exercise of that authority can take many forms. In the alcohol serving example, the airline or the captain might be prosecuted in criminal courts. Aircraft have been impounded once they land. Offenders who, for example, cause a disturbance on a flight can be prosecuted once they land. Aircraft that appear to be breaking the law can be intercepted in flight, and in extremely rare cases military aircraft can and have shot down civilian aircraft.


Do questions about video game soundtracks belong in Music Fans, or Arqade?

Question: Do questions about video game soundtracks belong here? I'm just curious as I do have a few  questions about various games and their OSTs. Would it be considered a video game question or a music question?
Comment: Music related questions appear to be [off-topic][1] at Arqade.

  [1]: http://meta.gaming.stackexchange.com/questions/7525/lets-get-rid-of-music-once-and-for-all
Comment: @pacoverflow That says nothing at all about topicality, it was part of a tag cleanup.  The linked question in that post is off-topic due to being about identifying music -- the converse, [identifying a game from music](http://meta.gaming.stackexchange.com/q/9816/6066), is on-topic.  I think the scope of acceptable music-related questions there is small, but it's not nonexistent.
Answer: If the question is entirely about the music, then it would be on-topic here.
If the question relates, in a direct way, to the game, then it should probably be asked on Arqade. Note that I'm not necessarily saying it would be off-topic here.
There are a number of sites that overlap with other sites (Science Fiction with Movies, Space Exploration with Astronomy, etc) and it is often up to the asker to decide which site will give them the best answer(s). If the question is on-topic on the site where it was originally asked, SE guidelines are to leave the question there, even if (in the judgement of some people) it would be better elsewhere.
Comment: "In any way" is far too restrictive a reason to ban a music-related question here.  Also see my comment above -- Arqade has a very limited scope when it comes to music-related questions.