How to use Wick's theorem to compute this matrix element?

Question: I wanted to see how to use Wick's theorem in practice (I know with Feynman diagrams it is better, but here I want to do this with Wick's theorem only), so I considered computing the matrix element for the process $\phi(p_1)+\psi(p_2)\mapsto \phi(p_3)+\psi(p_4)$ considering following lagrangian at first order in $\lambda$
$$\mathcal{L}=\partial_\mu\phi \partial ^\mu\phi -\dfrac{m^2}{2}\phi^2+\partial_\mu\psi \partial^\mu \psi-\dfrac{\mu^2}{2}\psi^2+\mathcal{L}_{\mathrm{int}}$$
where
$$\mathcal{L}_{\mathrm{int}}=-\dfrac{\lambda}{4}\phi^2\psi^2.$$
so we have two scalar fields with masses $m$ and $\mu$ which interact through this lagrangian.
We have an initial state with two particles with momenta $p_1$ and $p_2$ each of each field and similarly for the final state. The LSZ reduction formula tells then that
$$\langle f | S|i\rangle=\left[i\int d^{4}x_1 e^{-i p_1x_1}(\Box_1+m^2)\right] \left[i\int d^{4}x_2 e^{-i p_2x_2}(\Box_2+\mu^2)\right] \\ \left[i\int d^{4}x_3 e^{i p_3x_3}(\Box_3+m^2)\right]\left[i\int d^{4}x_4 e^{-i p_4x_4}(\Box_4+\mu^2)\right]\langle \Omega | T\{\phi_1\psi_2\phi_3\psi_4\}|\Omega\rangle$$
where I rename $\phi(x_i)=\phi_i$ and $\psi(x_i)=\psi_i$ for simplicity. Now I know that I can write
$$\langle \Omega | T\{\phi_1\psi_2\phi_3\psi_4\} |\Omega\rangle=\dfrac{\langle 0 |T\{\phi_1\psi_2\phi_3\psi_4 e^{i\int \mathcal{L}_{\mathrm{int}}}\} |0\rangle}{\langle 0|T\{e^{i \int \mathcal{L}_{\mathrm{int}}}\}|0\rangle}$$
Now I need to use Wick's theorem. Since I want the result for $O(\lambda)$ I expand the exponentials as
$$e^{i\int\mathcal{L}_{\mathrm{int}}}\approx1+i \int \mathcal{L}_{\mathrm{int}} d^4x=1-i\dfrac{\lambda}{4} \int \phi_{x}\phi_x \psi_x\psi_x d^4x.$$
Thus the numerator becomes
$$\mathcal{N}=\langle 0 | T\{\phi_1\psi_2\phi_3\psi_4\}|0\rangle-i\dfrac{\lambda}{4}\int d^4x \langle 0 |T\{\phi_1\phi_3\phi_x\phi_x\psi_2\psi_4\psi_x\psi_x\} |0\rangle$$
while the denominator becomes
$$\mathcal{D}=1-i\dfrac{\lambda}{4}\int d^4x\langle 0 |T\{\phi_x\phi_x\psi_x\psi_x\}|0\rangle=1-i\dfrac{\lambda}{4}\int d^4 x D_{xx}^\phi D_{xx}^\psi$$
with the notation $D_{ab}^{\circ}$ being the propagator for $\circ$ between $a$ and $b$.
For the numerator I've listed all possible full contractions and end up finding
$$\mathcal{N}=D_{13}^\phi D_{24}^\psi - \dfrac{i\lambda}{4}\int d^4 x\left[D_{13}^\phi D_{xx}^\phi D_{24}^\psi D_{xx}^\psi+2D_{13}^\phi D_{xx}^\phi D_{2x}^\psi D_{4x}^\psi+D_{1x}^\phi D_{3x}^\phi D_{24}^\psi D_{xx}^\psi+4D_{1x}^\phi D_{3x}^\phi D_{2x}^\psi D_{4x}^\psi\right]$$
and know we would need to let all those KG operators hit the object $\mathcal{N}/\mathcal{D}$ and I'm stuck because this got horrible.
It  turns out that we can factor the denominator out of the first term of the numerator so that we get
$$\dfrac{\mathcal{N}}{\mathcal{D}}=\dfrac{D_{13}^\phi D_{24}^\psi \mathcal{D}-\dfrac{i\lambda}{2} \int d^4x D_{13}^\phi D_{xx}^\phi D_{2x}^\psi D_{4x}^\psi-\dfrac{i\lambda}{2}\int d^4x D_{1x}^\phi D_{3x}^\phi D_{24}^\psi D_{xx}^\psi-i\lambda \int d^4x D_{1x}^\phi D_{3x}^\phi D_{2x}^\psi D_{4x}^\psi}{\mathcal{D}}$$
I believe this is not the right way to do so. The denominator won't cancel.
What is the correct way to use Wick's theorem directly to compute this matrix element?
Comment: The correct way is to use Feynman diagrams and see that the denominator factorises out of the numerator when you consider terms of all order.
Answer: That is not so horrible actually. Division by denominator just removes disconnected diagrams with vacuum-vacuum factors. So this is taken into account dropping from scratch such contributions. Once this is done, LSZ in momentum space is trivial, at least at tree level. Just amputate external propagators and put all on shell with suitable polarization vectors ( if spin > 0). All this is discussed in great details, e.g. , in Peskin's book.


sign languages and mute people

Question: Wikipedia has a lot of information about sign languages spoken around the world and references them as being spoken by deaf people. What I don't understand is, why wouldn't such languages also be used by mute people (people who are unable to produce verbal sounded speech)? (if such were the case, Wikipedia would clearly state such languages would be also spoken by mute people, so what am I missing?)
Comment: Are you asking about people who are unable to speak but *do* have hearing?
Answer: I guess, you simply misunderstood.
Using spoken language naturally requires both abilities, hearing and talking. Therefore, a person who has difficulty with any of these abilities (or both) is forced to use sign language.
From the medical standpoint, hearing impairment at birth leads to inability to learn how to talk, so such people, even though their vocal tract is fully functional, may have difficulty to reproduce sounds of speech. However, there are modern training techniques simplifying the process of learning.
Comment: @JackMaddington, [Auditory Oral Eduction](http://www.asha.org/uploadedFiles/asha/publications/cicsd/2008FTeachingDeafChildrentoTalk.pdf) by Jean S. Moog seems to be what you need (PDF). They also have [app for smartphone](http://www.audiologyonline.com/articles/auditory-oral-education-teaching-deaf-1248). Also, [this answer at Yahoo](https://answers.yahoo.com/question/index?qid=20070803095540AAWd9DS) provides with some more details.
Comment: Thank you for your answer. Could you please point me to what such modern learning techniques you mention may be?
Comment: Do you know if people who can hear tend to use manually coded languages or sign languages?

sign languages and mute people


Frame dragging around a black hole

Question:
If you have one stationary non-rotating black hole, being orbited by a 2 or more black holes just outside each other's event horizons does this alter the size of the central black hole's event horizon?
What's the answer to this thought experiment, if you put a spaceship into orbit around the central black hole. and it Falls into the event horizon just barely, and then introduce the multiple black holes orbiting just outside the central black hole's event horizon would it enable the spaceship to escape central black hole's event horizon via the pull of the exterior orbiting black holes. (I don't know if rotating or non-rotating would have any effect on the event horizon._
Answer: First of all if two black holes are orbiting each other with their horizons almost touching, they will very quickly merge into one black hole.  Even if they are orbiting at 10 times the horizon radius, they still will merge in a relatively short time.  The reason that they merge is that the closely orbiting black holes will be radiating a significant amount of their orbital energy as gravitational waves. The energy for the outgoing gravitational waves will come from the orbital energy of the black holes which will force them to get closer to each other which will increase the gravitational radiation in a runaway process that quickly results in the black hole mergers.  You can see many interesting videos of simulations of this process at this website: http://www.black-holes.org/explore2.html .
In the second part of your question, I think you are trying to arrange things such that the spaceship is sucked out of the event horizon of the first black hole by the second black.  Now, if you look at the videos, you will see that when the black holes are far from each other, the event horizons that are facing each other get flattened somewhat, which I think is the effect you are looking for that you think might allow the spaceship to escape.  However, if you look at the videos, you see that as the holes get even closer to each other the event horizons "reach" out towards each other and as the two cusps from each hole touch, then the black holes quickly merge into one black hole.
Here is a frame from a movie showing the event horizons flattened and the beginning of the cusps forming which will lead to the merger:

The problem with your scheme for escaping the black hole is that the spaceship will have already fallen into the singularity by the time you move the second black hole in close enough to "flatten" the event horizon.  The problem is that once the spaceship crosses the event horizon, the future time-like direction has become rotated into a spatial direction towards the black hole singularity at the center. See this answer on Astronomy Stack Exchange for more of an explanation: Why can't you escape a black hole?
Here is the image from that question showing how the time direction gets rotated towards the center of the black hole:
Answer: If a black hole is orbited by even just one other black hole, the event horizon bulges out towards it and increases in area.
If a spaceship is inside an event horizon it cannot escape no matter what you do. This is simply because the definition of the event horizon is the boundary of the region from which you cannot escape to infinity taking into account everything else happening in the universe present and future.
Comment: @Todd, I dont think you have understood the answer. Everything inside the event horizon cannot return to the outside universe by definition of the event horizon. If you find a way to get them back then they were not inside the event horizon in the first place. It is just a one way separation though. Someone outside cannot see what happens inside but someone inside can see some of what happens outside. You are mistaking your own misunderstanding for other peoples.
Comment: I have to say that this doesn't make sense to me yet, I would've assumed that the event horizons would've retreated towards the singularity versus expanding outward, my reasoning is the event horizon is the marker where  a particle would have to travel faster than the speed of light to escape, and time has slowed down so much  from the particle viewpoint,that the universe has aged tremendously,
Comment: I think that I get all that but,  if a particle  is emitted from a gun right below the event horizon, and a neutron star is introduced just beyond the event horizon from the particle it should reduce the energy necessary for the particles to escape, Because the neutron stars It's gravity should counterbalance the energy in that localized area somewhat.  I get the impression that people believe that everything inside the event horizon is separated from the universe, but that doesn't make sense to me either it seems it's more a lack of understanding what actually happens.

Frame dragging around a black hole


What is the matrix of the iSwap gate?

Question: Mostly I'm confused over whether the common convention is to use +$i$ or -$i$ along the anti-diagonal of the middle $2\times 2$ block.
Answer:
Mostly I'm confused over whether the common convention is to use +i or
  -i along the anti-diagonal of the middle 2x2 block.

The former. There are two $+i$'s along the anti-diagonal of the middle $2\times 2$ block of the iSWAP gate. See page 95 here[$\dagger$].

[$\dagger$]: Explorations in Computer Science (Quantum Gates) - Colin P. Williams
Answer: Whether you use $+i$ or $-i$ is entirely up to you.  After all, your definition of $\pm i$ is merely a convention.  On the other hand, I think I've only ever seen it with $+i$.
On a more general footing, you can consider that iSWAP is the gate obtained by time-evolving with an XX interaction ($H=-\sigma_x\otimes\sigma_x - \sigma_y\otimes\sigma_y$), in which case it depends on which sign of $i$ in the Schrödinger equation and for the Hamiltonian you prefer.  (You get $+i$ if you evolve with $\exp[-iHt]$, $t=\pi/4$, and chose the minus sign in the Hamiltonian as above, i.e. a ferromagnet).
Comment: You're right that if you *globally* replace +i by -i in every single gate, that all measurement expectations are identical. But typically you'd be combining the iswap with other existing gates that already have a convention (e.g. $S = \text{diag}(1, i)$), in which case the choice of +i vs -i for the iswap has observable consequences. [Here's an example circuit with that property.](https://algassert.com/quirk#circuit={"cols":[["H","H"],["~lnpf"],["H","H"],["Z^½"],["X","•"],[1,"H"]],"gates":[{"id":"~lnpf","name":"iSwap","matrix":"{{1,0,0,0},{0,0,i,0},{0,i,0,0},{0,0,0,1}}"}]})
Comment: @CraigGidney Sure. But then, again, it depends how you define your other gates, such as $Z^{1/2}$, for which different conventions might be used as well.  In practice, for gates which come from a time evolution (such as iSWAP) the 2-qubit gates are likely the ones which fix the choice of $i$, since it is typically easy to reverse the sign of one-qubit Hamiltonians but not of two-qubit Hamiltonians.
Comment: Mathematically, the operation of conjugating all complex numbers is a [non-trivial field automorphism](https://en.wikipedia.org/wiki/Automorphism#Examples) of $\mathbb{C}$ that fixes $\mathbb{R}$. In particular, all measurement expectations remain fixed under this symmetry. There do exist other automorphisms of $\mathbb{C}$, but they are [wild](https://math.stackexchange.com/questions/412010/wild-automorphisms-of-the-complex-numbers/412034)...

What is the matrix of the iSwap gate?


Send Email to Distribution List using SharePoint Designer Workflow 2013

Question: Is it possible to send email to Distribution Group using SharePoint Designer Workflow 2013? I have been trying to send email but it does not resolve to a proper name in SharePoint Designer 2013.
Comment: what error you are getting?The selected user(s) may not be valid on the site this workflow is published on?
Answer: not possible, as it is by design in SharePoint 2013 Designer workflows, if you want to use this functionality you have to use the SharePoint 2010 workflows. SharePoint is attempting to validate the users within the Distribution Group using REST services validation. Microsoft remove sending email to DL or security groups or external users in SP 2013 and up.
SharePoint 2013 workflows can only send emails to organization users.
Their is workaround Microsoft folks mentioned on his blog: SharePoint 2013 – Unable to send emails to external email addresses (SharePoint 2013 workflows)
Also you up vote and put pressure on MSFT bring back this functionality over here: SharePoint 2013 workflow email to distribution list


Servo motor vibration problem

Question: I'm working on DIY robotic arm. Robotic arm has 5 servos. The problem is that servo motors are shaking. I found different solutions but none of them works. What happens is that when I connect one PWM pin it works fine. Then add second pin and it works fine and so on. But when I connect power supply when all 5 pins are connected to ESP32 microcontroller it starts vibrating. I tried to power all servo motors separately but it doesn't work either. Does anyone have similar experience?
P.S. I use JMT200 servo motors with 50 Hz frequency and 800 ~ 2200 uS pulse width. Here is link https://www.amazon.com/JMT-Happymodel-Steering-Suitable-12v-24v/dp/B086HKQTC5
Comment: Also, what do you mean when you say you've tried powering the servos separately? Do you mean you're using different power supplies for each one, or do you mean you've wired them individually back to the same power supply (as opposed to, for example, wired back to the same power pin on the microcontroller?)
Comment: I'm having a hard time understanding how this is setup - is the same PWM pin on your controller connected to ALL the servos? Are you trying to drive all of them to the same angle?
Comment: the way your description is worded, you do not connect power until all five motors are connected to control signals .... what happens if you connect one control signal to all five motors?
Answer: In my experience, when a servo is shaking, that's how it tells you its power source (battery, etc) is inadequate. Especially if the servo hums or buzzes at around the command frequency (50 Hz in your case).
That beefy servo model you cite is rated at 12V-24V with a stall current of like 11 amps. Normal operating current will be less, but running all five servos at once will be demanding.
Personally I would try two multimeter measurements.

Voltage sag. Set up to measure the voltage as close to the servo as you can, then run the servos in "shaking" mode. I suspect the voltage will be significantly less than the 12 V those servos need at minimum.

"Normal" current. Set up to measure the current drawn by one servo. With a mechanical load on it (e.g., robot arm parts) command the servo to move from one end of its range to the other end. I hope your ammeter reading will stabilize in the time the servo takes to travel its full range.

If your voltage measurement is low, that confirms the voltage-sag hypothesis. If it's normal, that still leaves the possibility of a bad connection between where you measured and the servo itself.
Your power source must be capable of supplying well in excess of the measured "normal" current, times five (the number of servos).  In fact, you may want it to be capable of delivering stall current to all five (like 50A) -- otherwise one stalled servo could disable all the other degrees of freedom.
If all that's ok too, I would (re)check the connections, and confirm the wires are fat enough to carry the current. Beyond that, ask for more help, providing more detail.

Servo motor vibration problem


Is there a resource to query gene expression similarity? Stratified by sex?

Question: We developed such a resource. The editors of "Bioinformatics" (at OUP) rejected the paper on the grounds that we did not run a comparison with "state-of-the-art" [similar] resources. Can someone help me find similar resources?
Link to our own resource, ExFiles.
Answer: There are some similar resources, which at the same time do not mix the ingredients in the same way as your tool. Hope that pointing out the respective differences will help your rebuttal or resubmission! e.g.:

A similar web service is part of flyrnai, where tissue-specific expression can also be compared based on sex, and genes can be queried by the similarity of their gene expression profile to other genes.
A resource which has some conceptual relatedness regarding sex-specific similarity in gene expression, and which is also based on the GTEx dataset, has recently been published in the form of tables by Gershoni et Pietrokovski, BMC Biol, 2017.
A very nice and broad resource of high-quality gene expression profiles on individual tissues, but also on response to stimuli, is EBI GXA. Though the web interface only allows to query sex-specific expression profiles, computationally minded people could readily compute (dis)similarity between samples after downloading the (well-structured) data dump of EBI GXA.
A similar tool in terms of the visualization of sex-specific expression patterns is part of gtexportal, though it seems limited to displaying a single gene.


Fill the user profile properties automatically in SharePoint 2013

Question: We want our user profile properties automatically filled from a list what should we do? We do not have complete user information in active directory so we want to use this excel list for fill the user profile properties in order to users do not fill the personal and contact information themselves is there any way to do that?
Answer: You will need a whole lot of script,
and the AD values will still overwrite the Profile values you set, so you need to disable that proces as well
It is best to use PowerShell and fill your AD from that Excel file


How can I achieve colour overlay effect in PS?

Question:
I am trying to achieve the color overlay effect on a image. I have tried Gradient Map, black and white, a new layer with fill color and reduced opacity. But none are giving the best result. What will be the best way to achieve this effect?
Comment: See my earlier answer to a similar question http://goo.gl/dV0HVI : Changing hex color of a graphic.
Comment: I think using a gradient map would be the best option. Just change the dark stop to be placed more so in the middle since most of the mid-tones are the darkest color. Other things you can do. Change the exposure/gamma settings or lower the contrast and slightly blur the image.
Comment: @ACEkin I'm curious why you used goo.gl for the link?
Comment: @ZachSaucier Abbreviated URL. I trust this is not a problem for the site.
Comment: @AndrewH Yea Gradient Map was the one that worked!
Answer: It's actually really quick to make something like this.
Open the file, Duplicate the layer so you have the original to fall back on.
Create a layer underneath the image and fill it with black.
Desaturate your image (Ctrl + Shift + U).
Create a blank layer above and add a gradient that you want. I did the same colour as your example.
Set the gradient layer to around 80% opacity.
Set your image layer to around 50% opacity.
Done!
Hope this helps,
R
My example:
Answer: I created the following using Duotone.

Image > Mode > Greyscale (you image first needs to be monotone before you can play with Duotone

Image > Mode > Duotone

Select your darkest tone you want to see and name "the ink", copy and paste your colour value as you will need it later

Add a Levels layer, you adjust you "white" so that it becomes a much darker tone. Adjust until your lightest tone is as dark as you want

Add a colour fill layer over everything and use the blending mode overlay, adjust the opacity until you are happy

Image > Mode > RGB
When prompted to flatten, do so otherwise the colours change

You are done!
Answer: Try the various blend modes found here: https://helpx.adobe.com/photoshop/using/blending-modes.html
Also, make sure your image has the proper contrast levels so any blend modes you use (e.g. Overlay) will display the best result.
Answer: Those are certainly options above, but I would think the "Colorize" option would be the easiest first step!
Quick Steps:

Image > Adjustments > Hue/Saturation
Check the Colorize box, and play around with the settings!
From there, if you need to do any other settings (low opacity color overlay, blurs, contrast changes, etc. etc), go for it.

Here are a few quick screenshots to demonstrate:
(p.s. I used a random image I do not own to demonstrate - I'm sorry!)
Comment: Its an amazing answer with great explanation but its not what its not perfect in terms of what i was looking for. Well i have achieved that effect with 90% accuracy using gradient map and adjusting the EXPOSURE and LEVELS.
Answer: I have achieved the effect of the above image using Gradient map and adjusting the Levels and Exposure.

[![Exposure][3]][3]
Answer: My process may yield a more defined image than you might be looking for, but it is quick and simple if it helps at all!
Step 1)  Create a new Layer Adjustment over your image (next to the folder icon on your layers window), pick the solid color option, pick a dark grey/blue color, and set the layer blending mode to color.
Step 2) Make the same layer from step 1, but instead of changing the blending mode, just lower the opacity to somewhere around 80%. Mine was set at 83%.
This allows you to play with the colors and add your own effects without destroying your original picture, cheers!


FX options pricing exchange rate regimes

Question: how can we estimate the impact of a exchange rate regime switch ( from fixed to float) on the options prices i'm talking about the moroccan case (EUR/MAD USD/MAD) options OTC , is there any stochastic model for this ?
thanks in advance
Answer: MAD has been pegged to a basket of EUR and USD. Recently the weight of EUR in the basket has been decreased in favor of USD, and there is discussion of making the exchange rate float more freely still.
A regime change often involves a jump of the spot exchange rate simultaneously to a jump in the volatility.  There are some such models even with analytic tractability : see the Duffie, Pan, & Singleton SVJ-Y-V model [1] for instance.  Estimating or calibrating such a complicated model for MAD may be unrealistic however.  There are lots of parameters and not so much good data to estimate from.
A simpler model that might do well is the Merton jump diffusion [2].  That has only jumps in spot, not vol, but the impact of spot jumps is bigger on vanillas anyway.  And that model is only 4 parameters to estimate, something you might calibrate to some vanilla quotes maybe with a fixed guess for the jump arrival rate.
[1]
http://pages.stern.nyu.edu/~dbackus/Disasters/DuffiePanSingleton%20jumps%20Econometrica%2000.PDF
[2] http://www.qfrc.uts.edu.au/research/research_papers/rp287.pdf
Comment: The problem is that , the process of changing from pegged to floating regime will start with widening the upper and lower boundaries between which the exchange rate could float , but i want to understand what's the consequences of floating rate on the pegs are weights will be unstable ?

Thanks for the answer


Can a star emit heat but no visible light?

Question: Can a star emit enough heat to allow human life on its planets, however emit no visible light? If so, what problems would this pose?
Comment: Welcome to Stack Exchange! While I know it is tempting, it's strongly discouraged to cross-post the same question in multiple SE sites. You are now accumulating answers in both sites, and *answer fragmentation* is a problem because future readers may find some answers and never know about the others.
Comment: [Cross-posted on Worldbuilding.SE](https://worldbuilding.stackexchange.com/q/190401/8732)
Comment: It has been closed on the other site.
Comment: You should be more specific about what you mean by "no visible light"; what is the specific limits for saying that it "emits visible light" in this context?
Comment: @RobJeffries thanks for the update! Looks like I'd picked the wrong horse, so *I've withdrawn my close vote here*.
Comment: Relevant meta discussion: https://astronomy.meta.stackexchange.com/questions/558/how-do-we-handle-questions-with-answers-on-other-sites/559
Comment: It is possible for a planet to have a stable orbit around a black hole.  Whether it could receive enough heat to be habitable is beyond my ability to answer.
Answer: The minimum temperature of an object classed as a "star" is something like 2700 K. Such an object, although emitting the bulk of its radiation in the infrared, would still emit something like a few per cent of its energy at visible wavelengths.
Note that the visible and near infrared spectra of cool stars are nothing like blackbodies, so if the calculation is important then you would need to look carefully at empirical or model spectra.
Lower temperature objects do exist - these are called brown dwarfs. Some have (a subset called Y dwarfs) been found that are only a few hundred kelvins, so a planet could orbit not far above their surface and receive a kW per square metre of infrared light.
A plausible scenario might be a brown dwarf of spectral type T7 (a T-dwarf), with a temperature of about 1000 K (e.g. Burgasser et al. 2002). Such an object has a luminosity of only $\sim 10^{-5} L_\odot$, so a planet would have to orbit at about 0.003 au (about 0.5 million km) to receive the same bolometric flux as does the Earth from the Sun. Such objects cannot be described as "invisible" at visible wavelengths, but a typical $R-J$ (red minus near infrared colour) is about 9 or 10 - indicating that there is thousands of times more flux in the near infrared than there is in the red part of the spectrum. An example of the spectrum of such an object is shown below (GL229b is a T7 brown dwarf). Note how the spectrum is nothing like a blackbody.

Edit: There is likely a limit to how close a planet can get to its parent body, depending on a comparison of its density with the density of "star" it is orbiting. Too close and it will break up due to tidal forces, but for an Earth-like planet, whch would be less dense than a brown dwarf or of similar density to a very low-mass star, then that limit is either about a stellar radius above it or very close to the surface respectively.
Edit 2: NB cool white dwarf stars might be considered, but the oldest, coldest ones in the Galaxy are still around 3500 K and their spectrum encroaches significantly into the visible band. It is possible though that the most massive white dwarfs ($>1 M_\odot$) in old binary systems could be cooler than 3000 K, though no definitive detection has been made (e.g. Kaplan et al. 2014).
Comment: Is temperature really a criterion here? Are black dwarfs not gonna be stars then?
Comment: The coolest white dwarf in the galaxy is about 3000 K and emits plenty of visible light (as a fraction of its total output). Yes, temperature is the most important criterion in any answer @Mithoron .
Answer: The short answer is no.
The spectrum of electromagnetic radiation emitted by a body follows a curve that depends on its temperature. This is called its "blackbody radiation." Even for objects whose blackbody curve peaks in the infrared (heat) portion of the spectrum, there is a small but significant portion of the curve also in the visible spectrum. You can see an interactive simulation at https://phet.colorado.edu/sims/html/blackbody-spectrum/latest/blackbody-spectrum_en.html
Using this tool, we see that in order to have almost no part of its blackbody curve in the visible spectrum, an object needs to be rather "cold"—even a lightbulb (the old kind; not the more modern LED or compact fluorescent) is hot enough to emit a significant amount of visible radiation; anything hotter will emit more and more in the visible spectrum.
Obviously, having a lightbulb as a "star" wouldn't provide enough heat to any planet orbiting it…
Comment: I'm not sure this is true as far as the thermal radiation is concerned. Why couldn't a planet orbit a body of say 1000 K or so, simply close enough that they still received 1 kW/m^2? Or they could receive less and have an atmosphere with more greenhouse gasses that were biocompatible with the local flora and fauna?
Comment: @PierrePaquette You cannot compare a lightbulb and a star! There are objects much warmer than the Sun's surface on Earth itself. The total radiated energy flux is σT^4 but Sun is quite large. If a cold object is much larger...
Comment: Well, a lightbulb is 2,500 K and we barely get any heat from it even at close distances, so for the planet to orbit close enough to a 1,000 K to get any heat from it, it would almost have to be touching it…
Comment: @VladimirF I agree, but if you look at the interactive simulation I mentioned, viz. https://phet.colorado.edu/sims/html/blackbody-spectrum/latest/blackbody-spectrum_en.html , you'll see that any object that's hot enough will emit a significant amount of visible light. I was using the lightbulb merely as an example of a "not-very-hot-object-that-still-emits-visible-light."
Comment: An observation on temperature:  When I was growing up I entered the kitchen one night and **saw** that a burner was on on our electric stove.  It was a deep red glow--completely invisible in normal light but obvious in the dark.  I don't know the temperature but it pretty much has to have been very cold by stellar standards.
Comment: @VladimirF: In the universe, "large" objects will be "warm". More concretely, anything larger than the sun will be much hotter than the 1000K mentioned by Pierre. This is necessary the case because a cold object both larger and heavier than the sun would collapse due to its own gravity. Only radiation pressure can keep the volume up. And when that radiation stops, you probably have a supernova on your hand.
Comment: @MSalters yes......
Answer: Possibly a planet could be habitable to humans while having some layers of chemicals or dust in its atmosphere that block out all visible wavelengths of light.  However, someone else would have to design such an atmosphere.
Perhaps the "planet" could actually be a giant exomoon oriting a giant exoplanet in another star system.
And possibly all the heat of the exomoon would come from inside it.  Tidal interactions with the planet and with other large moons of the planet could produce a lot of internal heat to warm up the surface of the exomoon so life was possible.
I believe it has been calculated that if such a planet sized exomoon of a giant exoplanet orbited too close to it's planet, it would have too much tidal heating and suffer a runaway greenhouse effect and become too hot for life.  So an exomoon orbiting somewhat outside that minimum distance should have enough tidal heating to raise it's surface temperature to be suitable for life, regardless of how little radiation it received from its star.
To avoid even a small percentage of light from the star reaching through the possibly opaque atmosphere one could avoid having a star.  Perhaps the giant exoplanet and its habitable exomoon are rogue planets wandering in interstellar space light years from the nearest star.  Thus the light that reaches the upper atmosphere of the planet would be star light, and it would be rather easy to filter out such dim light with atmopsheric layers.
But without intense sunlight, there wouldn't be any photosynthesis, and the free oxygen in the atmosphere of Earth is believed to have been produced by photosynthesis.  An oxygen rich atmosphere is necessary to provide sufficient energy for large landbased life forms.
So a writer of a story set on such a world would have to:
One) find a plausible natural method  of producing an oxygen rich atmosphere without photosynthesis,
or else:
Two) explain that some advanced civilization terraformed the world and gave it an oxygen rich atmosphere,
or else:
Three) find a plausible replacement for oxygen in the biochemestry of the alien life on that world.
And another problem is that in a world without visible light frequencies reaching the surface but with temperatures similar to Earth, many of the animals would have eyes that see the infra red radiation that all the objects and lifeforms emit at temperatures similar to those of Earth.  So unless a writer plans to give his creatures infra red vision, no world warm enough for liquid water and for Earth like life will be dark enough for his purposes.
If every source of visible radiation is cut off, the lifeforms will evolve eyes capable of seeing with infra red light emitted by all objects at Earth like temperatures.
Comment: "Can a star emit heat but no visible light?"
Comment: Or maybe it's stuck in L₂ in the eternal shade of a Hot Jupiter?
Answer: What if the star was surrounded by a large dust cloud? Then the visible radiation would get stopped, while the dust cloud would eventually heat up and emit the infrared. The cloud could be orders of magnitude larger than the star, which means that the energy into the dust cloud is still equal to the energy out, just in different frequencies. In fact, the dust cloud wouldn't have to even be completely spherical. It could just be a donut that sat between the star and the planet, while regular radiation escaped the star at the poles.
Comment: Space dust is not that thick stuff we find under our furniture. It's actually less dense than the atmosphere we breathe. Even thick dust clouds only obscure about 6–7 magnitudes after *light-years* of thickness, so it would be unlikely for dust to obscure a local star from its neighboring planets.
Comment: Light exerts pressure.  It takes only a few million years for a star to blow away the dust cloud that it formed from.
Comment: the star would still be emitting light, even IF that light was being absorbed by a cloud of dust


Books and resources on how policies/regulations are made on exchanges like NYSE, NASDAQ, LSE, etc?

Question:
Different stock exchanges (for example, NYSE vs KRX) have similar but different regulations overall. Each exchange has different concerns and each exchange has a different approach to handle problems like volatility, etc.

How can I learn more about the thought process that goes into making policies/regulations to handle such problems?

Is there a specific discipline that studies financial exchanges and their regulations? Market Economics? I think that's too broad a term.

Bonus question: How do governments decide when to intervene on bad regulations/policies made by financial exchange marketplaces (? by this I mean: stock markets, foreign exchange markets, etc)

Maybe I don't have a clear question. In that case, can you provide some relevant introductory references or keywords to research?

If my question is not appropriate here, can you suggest where else I can get answers?
Answer: This document, published by the International Organization of Securities Commissions, states three objectives and describes thirty-eight principles of securities regulation:
https://www.iosco.org/library/pubdocs/pdf/IOSCOPD561.pdf
Objectives

Protect investors

ensuring that markets are fair, efficient and transparent;

reducing systemic risk.

The Securities and Exchange Commission (SEC) is the official federal regulator in the United States. Administrative law regulations are made in a context of procedures relating to the Federal Register and/or Code of Federal Regulations. This is a Guide to the Rule Making Process:
https://www.federalregister.gov/uploads/2011/01/the_rulemaking_process.pdf
North American Securities Administrators Association (NASAA) has much information about its efforts to solve problems under the objectives published on this site:
https://www.nasaa.org/
Rules established by government authority or customs with commercial authority are efforts to solve a particular social problem, procedures to solve those types of problems, and procedures to monitor behavior and enforce rules. Your research would be based on comparisons of these elements in unique case studies or contexts regardless of the information sources which should be available to the public.


In what manner and to which degree would programming on a hypothetical ternary computer differ than from binary computers?

Question: To expound upon my question as mentioned in the title, I am researching, out of curiosity, what the implications of a (balanced) ternary based computer would be, besides obvious things such as greater "density" of information.  Clearly, ternary operators would be "easier" to implement, or more "natural" if you will, than binary ones.  Also, bitwise operations would need to be replaced by tritwise operators.  I am aware of the benefits and drawbacks to balanced ternary on the hardware level, but I want to know what that would mean for typical writing programs in a C-level language.  Could a C compiler be written for a ternary computer without simply emulating a binary one?  If not, how much would a language like C, or even Lisp-like languages need to be altered to take advantage of the balanced ternary system? I'm sort of a noob, so I apologize if I said anything inane as a result.  Thanks for answering!
Comment: Why isn't the answer "Obviously none"?
Comment: Welcome to cstheory, a Q&A site for *research-level* questions in *theoretical computer science* (TCS). Your question does not appear to be a research-level question in TCS. Please see the [FAQ] for more information on what is meant by this and suggestions for sites that might welcome your question. Finally, if your question is closed for being out of scope, and you believe you can edit the question to make it a research-level question, please feel free to do so. Closing is not permanent and questions can be reopened, check the [FAQ] for more information.
Comment: Isn't it worth treating this question as a question about the asymptotics of division algorithms like I did below? Not exactly research level, but no longer silly.
Answer: As you know, any language providing bitwise operations like C must introduce additional complexity into the machine code if your n-ary CPU did not offer these operations itself.  In other words, either the CPU or the C compiler must provide a couple division algorithms optimized for specific fixed constant denominators.
Interestingly, your C compiler already does this when converting between array indexes and pointer arithmetic.  In fact, it tunes the division by constant algorithm at compile time according to sizeof(...) and alignment (pdf).
In other words, there is a small risk the machine code would bloat up in size, and endianness-like issues would suck up more programmer time, but otherwise I double much would change, either for better or worse.
Answer: At least one ternary computer was built in 1958, see http://en.wikipedia.org/wiki/Setun, so it's not a completely hypotethical concept. Note that if a new tri-state nanodevice is discovered, ternary computers may be built again.
A computers with exotic number representations can be better suited for special tasks - e.g. for exact real arithmetic, but for most tasks they will be the same to program. The abovementioned Setun was using not usual ternary numbers, but so called http://en.wikipedia.org/wiki/Balanced_ternary which is an interesting representation of signed numbers using negative-valued digits
See also http://en.wikipedia.org/wiki/Ternary_computer
Answer: C's not a terribly good example, because it provides access to many low-level details that, I believe, really assume that the computer is based on binary with 8-bit words.
As a thought exercise, you could add
n-ary (what's-the-generalization-of-trit)wise operations into the C language as it exists. As Burdges suggests in his answer, the programmer could reasonably expect that a tritwise operation would be more efficient on the tritwise architecture, and the bitwise operation would be more efficient on the bitwise architecture. But what do you do about sizeof()? To deal with that, you'd probably need an incompatible "ternary C" that has a different sizeof (reporting the size in "trites" or whatever). This wouldn't be terribly difficult, I imagine (at least relative to the difficulty of writing a C compiler, which is hard).
Lisp is a better example, since it abstracts out irrelevant low-level details like the number of bytes in an object's memory representation. I imagine a tertiary Lisp compiler would look nearly the same as a binary Lisp compiler, save for the code emitted when you do bitwise operations.
Comment: You'll remember that "bit" is a portmanteau for "binary digit", so the generalization is simply "digit".


Humans have Cannabinoid receptors. Does that mean we're meant to consume cannabis?

Question: I know the answer is no. But what then explains the name of these receptors being specific to Cannabinoid found in cannabis? Aren't Cannabinoid receptors exclusive to Cannabinoid? Why are they named like that, if not?
Comment: This is a case where the receptors were discovered while researching cannabinoids, but before they had discovered the endogenous chemicals that bind to the receptors. Once those were found, they were named the [endocannabinoids](https://en.wikipedia.org/wiki/Endocannabinoid_system).
Comment: You also have ammonia receptors. Are we also meant to smell it?
Answer: Receptors
Any drug or compound with specific effects has a receptor. You can read about this general concept in Goodman and Gillman's The Pharmacological Basis of Therapeutics. Chapter 1 introduces the concept, chapters 3 and 5 expand further. As far as the history of this concept is concerned, receptors mediating the specificity of action was first clearly articulated by Paul Ehrlich (in the context of dyes and toxins), and further developed by John Langley (and Ehrlich again in response). Cannabis and cannabinoids are not unique in this regard. Illicit and therapeutic drugs of all kinds have a target binding sites (receptors). In almost all cases, these receptors are bound by endogenous compounds as well.
Does having a receptor mean we should consume something?
There was a case to be made that having a great number of receptors that bind psychoactive compounds in cannabis means there is a physiologic role for some cannabinoid (especially given the pattern of expression) and suggested the existence of an endogenous cannabinoid before it was discovered. This was discussed in the nature paper that first identified the receptor and its functional expression and in the science paper that reported the discovery of endocannabinoids. Generally, it doesn't suggest that we are "meant to consume cannabis". Toxins and poisons also have receptors, and we certainly don't want to consume those.
As far as the name is concerned, the comment by @user137 is correct. Receptors are sometimes named by exogenous drugs that activate them, in particular when these compounds are discovered and studied before an endogenous ligand is found. Opioid receptors are another example.
Comment: So I think I had the misconception that cannabinoid receptors allow only cannabinoid to bind with it. Can you confirm that multiple ligands can bind to a single substrate? (So there's no exclusive lock and key mechanism)
Comment: @yathish that's correct. Cannabinoid is an entire class of compounds. Many different specific cannabinoids bind cannabinoid receptors, with varying affinities. The lock and key model is useful, but not entirely accurate. For most (possibly all) receptors, more than one ligand can bind.
Answer: In addition to De Novo's excellent answer, I would like to add that sometimes, the fact that we have receptors for something is precisely a sign that we should not consume that thing.
When it comes to taste and smell in particular, many receptors are evolutionarily conserved precisely because their physiological role is to warn us of a danger. For example, diamines such as putrescine and cadaverine smell well, terrible, as their names suggest. And we are very good at detecting these smells, because these molecules are produced during organic matter putrefaction; in other words, we have receptors (recently identified) designed specifically to tell us that certain foods are not suitable for consumption.
The same principle applies to olfactory receptors for volatile molecules harboring sulfhydryl (-SH) groups, that often smell like rotten eggs or feces - for the same reason. Mercaptan is even used to give natural gas its distinctive smell (it's initially odorless), making sure that we can detect any gas leak that could cause an accident - because we have really good receptors for it.
Answer: Cannabinoid receptors are a part of the endocannabinoid system, which encompasses native to our body ligands such as Anandamide, 2-Arachidonoylglycerol, Palmitoylethanolamide, and a few others.
The reason they are named after the cannabis plant is because of the role cannabinoids played in identifying and characterizing those receptors, a pattern that you'll see in biochemistry a lot, e.g. AMPAr and NMDAr receptors named because AMPA/NMDA are their selective ligands, even though both are glutamatergic receptors, nicotinic/muscarinic acetylcholine receptors, or CART(Cocaine- and Amphetamine-Regulated Transcript) named for the fact that cocaine and amphetamine regulate its transcription levels.
For what it's worth, not all cannabinoid system proteins are named after cannabis, such as the more recently characterized NAGly, GPR55, and GPR119 receptors.


Difficulty typing on Iphone because of fat fingers

Question: I have fat fingers hence this makes typing on the Iphone which has a small screen difficult , I always mistyped

Are there any ways to overcome this problem ???
Comment: iPhones support bluetooth keyboards.
Answer: Practice makes perfect, but the real differentiator between people that struggle to learn to type on glass and those that become proficient is the mindset when you learn.
I would encourage anyone struggling with this to give themselves a huge window to learn. Play around with the keyboard for 5 minutes, don't worry about your fingers covering the letters.
Also, experiment with the voiceover and assistive touch settings to see what different input lag settings do and also changing the entire meaning of a tap (with voiceover) does for your concept of touch control.
Also, when playing - see if you can place your finger in the empty zone between three characters (two on one row and the key below the gap). Plop your finger down but don't lift it. Then pivot it gently, rolling on the fleshy part of your finger and see how the contact area changes as you rotate your finger. You can drop your finger where you think the letter is and then adjust before lifting.
After playing a bit, you will quickly get better as long as you don't get too frustrated with yourself. Just as learning to ride a bicycle can be hard initially, this too is a fine motor skill you need to practice.
I've never met anyone that couldn't learn to type due to physical size of their digits. Of course nerve / control / other physical limitations such as missing bones or digits is an entirely different situation than being used to seeing where you tap and/or not training up a new skill.
If you have an issue typing, there are now switch controls, voiceover, assistive touch, accessibility options galore on iPhone and iOS.
If your issue is attitude or feeling it's not worth learning a new skill since you prefer a keyboard you can connect a keyboard or buckle up and start learning a new skill.
Don't allow yourself to think you're too impatient, too old, too young, too busy, too frustrated or just don't care to learn a new skill. There's nothing wrong with any of that, but if you give yourself a few days to adjust I think you just may start to like the keyboard or at least reach a level of peace and possibly comfort with how the touch detection works.
Answer: I recommend turning the phone into landscape mode whenever possible (sideways orientation). This allows the keyboard to become significantly larger with each key being larger and having more space in between it and the next one.
There are some apps that are portrait only; they prevent you from using the landscape keyboard. However, many, probably the majority of, apps allow landscape mode. Basically all of the text-entry apps do allow landscape mode such as Messages, Email, Notes, Evernote, and the like.
Answer: You can try a capacitive stylus for iPhone (like these ones).
Answer: I can relate to someone who has a hard time typing using their fingers on the IPhone.  I have something called Raynaud's Syndrome which makes my fingers cold all the time.  Even in air conditioning my fingers and hands will turn a bluish purple color and I am guessing that is the reason that no matter how many times I put my fingers on the keyboard or another example when I try to answer a call and someone has left me a message and I need to press on voicemail nothing happens.  My husband can come along and he puts his finger on it and gets it to work.  Therefore, I always use a stylus to type.  Being that I worked my entire career knowing how to type using both hands in the beginning this took me awhile to get my speed up, but now I can type really fast with a stylus.  I see nothing wrong with using a stylus as long as it gets the job done.
Answer: I had the same problem so I created an iPhone keyboard that solves this. It is free and open sorce.
http://www.milgra.com/fat-fingers-keyboard.html


Who funds the Teen Titans?

Question: Where does the money for the Teen Titans come from. Who built and pays for the tower? I know Robin on the team has access to a lot of money.
Comment: Which version of the Titans are you referring to? (animated, comics, etc.)
Comment: Raven and Starfire turn tricks out the back.....

okay i have no idea, but i always assumed robin was providing it, or the city itself. Why they even need a giant skyscraper is beyond me.
Comment: Only semi-seriously: Maybe they lease antenna access to cell phone companies?  Or Cyborg licenses patents to some of his advanced technology?  Or TT only occupy 10% of the building, perhaps with Wayne Enterprises occupying the rest? :-)
Comment: I just assumed the Justice League funded them.
Comment: Thanks for the answers, I forgot to say Animated Teen Titans but I don't see how that would change the most likely answer of Bruce Wayne.
Comment: Why can't Bruce Wayne fund them?
Answer: There are too many versions of the Teen Titans to easily answer this question. In most continuity versions of the team (Pre-Crisis, for example) can be answered by saying Bruce Wayne (Batman) provided the funding for most of the land acquisitions and technical resources (assuming they were not built by the Titans themselves) for the team in its early days. Some continuity versions of the team were also directly supported by the same agencies which supported the Justice League of America.

The First Teen Titans

Robin (Dick Grayson), Kid Flash (Wally West), and Aqualad (Garth) — the sidekicks of Justice League members Batman, the Flash, and Aquaman — teamed up to defeat a weather-controlling villain known as Mister Twister in The Brave and the Bold #54 (July 1964) by writer Bob Haney and artist Bruno Premiani.

They subsequently appeared under the name "Teen Titans" in The Brave and the Bold #60 (July 1965), joined by Wonder Woman's younger sister Wonder Girl (Donna Troy) in her first appearance. After next being featured in Showcase #59 (December 1965), the Teen Titans were spun off into their own series with Teen Titans #1 (cover-dated February 1966) by Haney and artist Nick Cardy.

The original Teen Titans were financed and supported by Bruce Wayne (Batman) and he gave them their first headquarters called the Titan's Lair.

Titans Lair was once a records storage facility owned by Wayne Enterprises. Bruce Wayne allowed his sidekick Robin the use of the empty silo during the time when Robin helped to form the original Teen Titans.
The one-level cavern is located beneath a cliff adjacent to the Gotham City River. Special emergency exits exist at the base of the cavern, which allowed the Titans the ability to come and go in secret. It also enabled Aqualad quick access to the nearby river and Atlantic Ocean. The Lair contained a concealed helipad for the Titans Helicopter as well as living quarters, cargo lift elevators, laboratories, a warehouse and a mechanic's shop.
This headquarters was later abandoned after being compromised by the villain Doctor Light.
Answer: The city may sponsor them in return for their service/role as guardians and protectors. Robin may also be referred to as Batman's sidekick, so they may be partially sponsored by Batman himself. Depends on which version of the Teen Titans you're talking about, as Monty129 has, rather, importantly pointed out.

Who funds the Teen Titans?


Translation for "Humbly yours in Christ"

Question: I am trying to find the correct translation for, "humbly yours in Christ" to put at the end of a letter. Would the translation "humilitate tua in Christo" be somewhat close? I have just recently begun studying Latin. Thank you very much for your help.
Answer: Though humilitas / humilis was mostly negative in classical Latin, it acquired its positive sense as a Christian virtue as early as the Vulgate (Matthew 11:29; James 4:6), Augustine (Confessions I.11) and certainly by the time of Aquinas (Summa Theologiae II-II, q. 161). This has a lot to do with the Christian emphasis on what Alasdair MacIntyre calls the "virtues of acknowledged dependence": whereas Aristotle only had the vice of pusillanimity, Aquinas acknowledges not only the vice but also the virtue of humility.
Another prefatory remark: the classical way of composing Latin letters (followed by authors as diverse as Cicero, Seneca, Petrarch, and Erasmus) is to name the sender and recipient at the beginning (e.g. "Seneca Lucilio suo salutem") and then to have a valediction at the end, often with the time and place. For more on this, see this question: Ending a letter in Latin. Nevertheless, there is also precedent for ending Latin letters in the way we are accustomed to.
A literal translation of your phrase is: humiliter tuus in Christo. I can't find any precedent for this, though, and I'm not sure if Latin shares this formula with English: it's strange for an adverb to modify a possessive pronoun.
I would suggest adding a noun, e.g. "servus" (=servant), for which I have found some precedent. You could thus close your letter with: humilis servus tuus in Christo [name]. This literally means, "Your humble servant in Christ." You could also substitute humillimus (="most humble").
Comment: @tony Again, "servus" has a vastly different meaning in a Christian context. See, for instance, Romans 1:1, or the Pope's title: "servus servorum Dei"
Comment: Hmm, can you give me some examples? From my (limited) knowledge of letter-writing in other European languages, I can't think of an example of "adverb + yours." Or perhaps I'm misunderstanding your comment: if your point is that it's only common in English, then that's what I was intending to say!
Comment: It is not strange to adverb to preceding a pronoun: it's just American English way. And this situation is rule for many other languages in such type of the letter-end cliché.
Comment: @Josh: (Oxford); servus, i (m) = a slave; as an adjective: servus-a-um--having the status of a slave, servile. Is this what you want?
Comment: @brianpck Ok. Look at here: British English - yours sincerely (pronoun+adverb), but American English (mostly) - sincerely yours (adverb+pronoun); Russian - iskrenne vash (adverb+pronoun); French - as cliché: bien à vous (dual treatment by me: or ajective+preposition 'to'+pronoun, so literally 'good for you', or adverb+(preposition-pronoun compound),  so literally 'pleasantly yours'), as speech example: sincèrement à vous/vôtre - 'sincerely yours' (adverb+(preposition-pronoun compound)/adverb+pronoun).
Comment: But it seems to be more useful for you. There was example similar to question theme: 'sincèrement vôtre en Jésus-Christ' in Trench. So you can use calque from French expression: 'sincērē vostrī(masc.)/vostrae(fem.) in Jesus Christus'.
Comment: It was answer to the topic-starter (@Josh)
Comment: Thank you very much. I didn't even think of rephrasing it as being, "your servant in Christ". Now I'll place more attention on the semantics during translation.
Answer: The expression; "humilitate tua in Christo" means "with your humility in Christ", not quite what you have requested. A second problem is that "humilitas" is harsher, in Latin, than "humility" in English e.g. lowness; meanness; insignificance (Oxford).
A possible alternative: "minister tibi in Christo" = "a servant to you in Christ".
Here, "minister" is not so obsequious or humiliating as "humilitas"; besides "servant", "minister" = attendant; accomplice; agent.
Lewis & Short give more examples e.g. promoter; helper; an abettor; accomplice.
Comment: Out of curiosity, why "tibi" instead of "tuus"?
Comment: @brianpck Since the verb *servire* is used with a dative, it makes sense to me to use the same case for the beneficiary of the corresponding noun. Perhaps I'm mislead by other languages, but I'd read a genitive or a possessive pronoun as ownership and a dative more as a favour. Tony, could you elaborate on this choice in your answer?
Comment: @brianpck & Joonas: The use of "tibi" seemed to be more personal (a servant to you) without being obsequious. I was unsure about the grammatical acceptability of this, and was anticipating a challenge. As for "servus" the thinking was that, in Rome, the servants and the slaves might have been one-and-the-same species, hence the Oxford definition. As you have indicated, "servus" would have evolved, with time. I liked the work you did (2016) in finding examples (Vulgate)  of sentences which included pairs of perfect subjunctives. Great!
Comment: @Joonas llmavirta: Please see comment to brianpck, above.
Comment: @brianpck: I forgot to reference the Q: https://latin.stackexchange.com/q/1179/1982 which included the Vulgate examples.
Answer: There was a greeting to a noble men in the former Austria-Hungary Empire: sounded like 'servus humillimus' (now clipped just to a 'servus' in some languages, which natives were citizens of the empire). Maybe it's possible to re-phrase expression in such way. Not adverb, but compound to modify pronoun. It sounds less pejoratively.
Answer: @Josh When I was answering to @brianpck, there was example from French. And I did give advice to use calque from this language - 'sincērē vostrī in JC'. But there is an another possible variant: 'sincērē vestrum (in JS)'.


What is the effect of a high dollar on the Canadian economy, investors, and consumers?

Question: Is a high dollar good or bad for the Canadian economy? Are investors affected differently from consumers because of this?
Comment: High compared with what?
Answer: It depends primarily on how the Canadian economy is designed i.e export oriented or import oriented. If you look at this, it shows more or less equal amount of exports and imports.
For the specific case of Canada, the exports would become costlier, because of a costlier dollar, but at the same time imports would become cheaper. This is only a generalization, not specific goodswise, which would require a more detailed ananlysis.
But investors have a different dilemma. Canadian investors would find  it cheaper to invest abroad so may channel their investments abroad because they may find it costlier to invest in Canada. While foreign investors would find it costlier to invest in Canada and may wait for later or invest somehwre else.
Then government may try to boost up investment and start lowering the interest rates, if it sees the rising dollar as detrimental for the Canadian economy and investments flowing abroad instead of Canada.
But what would be the final outcome of the whole rigmarole is little difficult to predict, because something is arriving and something is departing and above all goverment is doing something or is going to do. But the basic gist is Canadian exporters will be sad and Canadian importers will be happy, but vice versa for foreign investors intending to invest in Canada.


Stack arduino, motor shield and lcd shield

Question: I made arduino-stack which consists of arduino r3, robotdf motor shild and robotdf lcd shield. But motor shield and lcd use same pins 4 and 5, so we have a conflict of pins. Can i use other pins?
Comment: Nope. Welcome to shields.
Comment: Technically you *can* rewire the shield. But this is a physical change, and different combinations of shields will require different rewiring. In the end you may be better off just using breakout boards instead.
Comment: @IgnacioVazquez-Abrams it would be possible if you modify the shield right? cutting through a wire, solder it to another pin?
Comment: @IgnacioVazquez-Abrams this variant is ok for me, thanks
Answer: Stack one shield on top of the Arduino itself and connect the other shield using wires. This way you can pick your own pin assignment for the 'external' shield.
Be careful when using a specific library though, sometimes the used pins are hard-coded in the library itself. Modifying the .h and .cpp files for the library is possible, so you could (hard code) assign your own used pins.


AirPrint and Apple Configurator

Question: I have a small office setup where I control certain functionality of a set of iPads. One of the things I need to do is to be able to allow a set of iPads to AirPrint, while keeping others from doing the same. Is there a way through either the Apple Configurator, or the iPhone Configuration Utility, to disable AirPrint by device?
Answer: What I ended up doing was to implement Printopia Pro, which incorporates user groups. This has the effect of locking down the printers except for the users who need access. If you own Printopia, you can get $20 off on an upgrade to Pro. If you need permission-based printing like I do, I'd recommend doing so.
Answer: It's not exactly what you are looking for but why don't you set a password.
Look here: http://support.apple.com/kb/PH11450?viewlocale=en_US.
You can share a printer and specify a user so who tries to print must enter a username and a password.
Comment: The printer is networked, not connected to a Mac or PC. I'd consider printing and requiring a password to do so, but the printer firmware doesn't have a facility to incorporate one (other than password protecting against unwanted changes).
Answer: It's a bit hackey but if your router supports it, you can whitelist only the traffic from the permitted MAC addresses to the printer.  The printer would probably still show up in the AirPrint menu, but wouldn't actually be usable by those blacklisted.
Comment: I use an Airport Extreme, which permits whitelisting to the extent that I can filter MAC addresses that connect to the network, but as far as filtering them based upon accessing the printer, I would have to look at it in more detail. That's a thought though.

AirPrint and Apple Configurator


How can I get Google to re-crawl my site's description?

Question: When I first submitted my website to Google my website's robots.txt had disallowed the search engines from fetching the URL and so whenever I enter my websites domain to check on google the description shows as "A description for this result is not available because of this site's robots.txt". But now I modified my robots.txt file to allow search engines to crawl the website. How can I force google to re-crawl my website's description?
Comment: Possible duplicate of [Need Google to recrawl the pages](http://webmasters.stackexchange.com/questions/52757/need-google-to-recrawl-the-pages)
Comment: It will happen in time. However, if your site is not too large, you can always do a Fetch as Google and Submit to Index in Google Search Console. It will take a couple of days to update - it is not immediate. You can do quite a few pages each day. I do not suggest submitting all of your pages unless your site is small, however, I do suggest you submit your most important pages plus a few. Cheers!!
Answer: Use the Submit to Index function of the Fetch as Google tool to re-crawl your URLs

Ask Google to crawl and index your URL
Click Submit to Index, shown next the status of a recent, successful fetch in the Fetches Table.
Select Crawl only this URL to submit one individual URL to the Google for re-crawling. You can submit up to 500 individual URLs in
  this way within a 30 day period.
Select Crawl this URL and its direct links to submit the URL as well as all the other pages that URL links to for re-crawling. You can
  submit up to 10 of requests of this kind within a 30 day period.
Click Submit to let Google know that your request is ready to be processed.


Can Lord Brahma give moksha? Can jivas enter Satyaloka after death?

Question: It is said that Lord Vishnu and Lord Shiva can give moksha to Their devotees in Their respective abodes i.e. Vaikuntha and Kailasha respectively. Now my question is whether or not, Lord Brahma give moksha? Can jivas after death attain Satyaloka (the abode of Lord Brahma)?
Comment: Definitely . why such a rudimentary question ?
Comment: Keep in mind that Moksha is a concept of being free. One who attains the Moksha get freed from the cycle of life and death. Also in various puranas it's been mentioned that each god has their own adobes like Ganeshloka for lord Ganesha. IN Ganesh purana there are mentions of multiple lokas being watched by a devotee of lord Ganesha while on the way to Ganeshloka.
So yes each god is capable of helping and guiding their devotees to the Moksha and each god has their own Adobes(Which are nothing but the place where the respective god lives).
Answer: For time being  I am only answering your question -  can Jivas after death attain Satyaloka?
The answer is Yes. The Yogi's and ordinary persons (dvija)  both can attain Satya-loka after death.
It's said in Brihad Aryanaka Upanishad   Chapter 6 -Brahman 2 - Mantra 15 that ,a ordinary Gruhastha who knows the Panchagni Vidya and who worship Brahma or Hiranyagarbha with devotion in forest reach Brahma-Loka.
Also the same detail description of Nivrutti Margi dvija ,attening Brahma loka through Devyana path  is given in  Canto 7 -Chapter 15 -Verses 52-55 of  Shreemad Bhagvat Purana.  Below is one verse.

अग्निः सूर्यो दिवा प्राह्णः शुक्लो राकोत्तरं स्वराट् । विश्वोऽथ तैजसः
प्राज्ञस्तुर्य आत्मा समन्वयात् ॥ 7.15.54॥
On his path of ascent, the progressive living entity enters the
different worlds of fire, the sun, the day, the end of the day, the
bright fortnight, the full moon, and the passing of the sun in the
north, along with their presiding demigods. When he enters Brahmaloka,
he enjoys life for many millions of years, and finally his material
designation comes to an end. He then comes to a subtle designation,
from which he attains the causal designation, witnessing all previous
states. Upon the annihilation of this causal state, he attains his
pure state, in which he identifies with the Supersoul. In this way the
living entity becomes transcendental.

Here  in the another  verse  from same purana this is repeated.

एतावाञ्जीवलोकस्य संस्थाभेदः समाहृतः । धर्मस्य ह्यनिमित्तस्य विपाकः
परमेष्ठ्यसौ ॥ 3.10.9॥
Thus is explained the arrangement of world of living beings. The
region of god Brahma is result of religious duties performed without
desiring their fruits.

So according to Upanishds an ordinary person who knows Panchagni Vidya and worships  (Satya Brahma) with devotion attain Satyaloka. And the puranas in simple manner says this thing as "a person attains Satya or Brahma  loka by performing religious duties without desiring their fruits.
Comment: Inn simple words Agnihotra , but we can find more detail about it in Brihad Aryanaka Upanishad Brhana 2 -of Chapter six . I will give you ref. from that upanishad  later in chat  :-)
Comment: BTW you can also check this wiki article - https://en.wikipedia.org/wiki/Panchagni_Vidya
Comment: What's Panchagni Vidya?
Comment: @SwiftPushkar but how come rituals give jnana as per vedanta ?
Answer: The Second Canto (Bhagavatam
2.5.39) also equates Brahmaloka
with the spiritual world,

mūrdhabhiḥ satya-
  lokas tu brahma-lokaḥ
  sanātanaḥ
"Satyaloka, the
  topmost planetary
  system, is situated on
  the head of the form.
  The spiritual planet
  Brahmaloka, however,
  is eternal."

valmiki ramayana say(Rama says to sita):—

देवगन्धर्वगोलोकान्ब्रह्मलोकां
  स्तथाऽपरान्।
  प्राप्नुवन्ति महात्मानो मातापितृपरायणाः।।
  2.30.37।।
मातापितृपरायणाः people devoted to the
  service of parents, महात्मानः great
  men,
  देवगन्धर्वगोलोकान् the world of the
  gods, gandharvas, and the cows or
  Visnu, ब्रह्मलोकम the world of
  Brahma, तथा and, अपरान् other worlds,
  प्राप्नुवन्ति will attain.
Great men who are devoted to the
  service of their parents attain the
  world of the gods, of gandharvas, of
  cows, of Visnu, of Brahma and other
  worlds.


Recording notes with the computer keyboard in Ableton Live

Question: I have enabled the Computer keyboard button, the Arm Session Recording, and playing/recording at the same time, plus the Midi Editor Preview. If I press the ASD buttons, I can hear notes (as long as it's not recording) but it is neither playing those notes nor writing them to the track. How do I get it to do this?
Comment: Have you read the manual on "Recording Into Session Slots"? https://www.ableton.com/en/manual/recording-new-clips/
Answer: I think you want to not have the session record armed or active. You want to just record into a clip. To record into a clip, all you have to do is record arm the track and then click the record button (circle) in one of the clip spaces on the track. There are a lot of relevant settings, like fixed length recording, that you might have to run down, but that's the basics of it.
One thing I note in the image is that the selected clip is in play mode and not record mode. You can tell because of the green triangle on the left side of the clip box. If it were recording into the clip, that would be a red circle. One way that might happen while the track is record armed is if you clicked the clip button once to begin recording and then clicked it again, which by default stops recording and starts playing the clip. Another way that might happen is if fixed length recording is on, then you click record and then don't play until after the fixed length is already exceeded then the clip can enter playback mode automatically. If you click the open circle to the right of the transport buttons that should put the clip in overdub mode and you should be able to play midi events into it.


Does slicing bigger image (2 MB~5 MB) helpful for loading sliced images on web for better appeal

Question: Well I am struggling between best practice and nice to have feature and need your opinion before embarking on fruit(less/full) endeavor.
To improve server performance its been suggested to have less server calls. But then I dislike the part where a big file takes a long time to load. I would rather prefer to load file in chunks for better appeal (like google map loads in layer/tiles).
What is the take of community on this?
Thanks
Answer: Its better you Use CDN (Content Delivery Network) for static images rendering in your webpage, which should be hosted in other Server or Cloud environment.
You'll surely see the performnace improvement.
Thanks


iCloud access through browser

Question: My iphone takes photos, automatically uploads them to the cloud in a cool way and then they arrive on my iPhoto without me having to do anything - that's excellent but is it also possible for me to view the photos online through a browser or similar? Apologies if this is a particularly easy question - my google-fu is failing me today...
Answer: Modern Answer (2016):
This is a feature of iCloud Photo Library, that launched in 2015 (and was in beta in 2014). With the updates to Photo Stream/iCloud Photo Library, your photo library is now viewable on iCloud.com.
Original Answer (2012):
This feature is called Photo Stream, and at this point, there is no web version of it.
The previous iteration of iCloud, which was called Mobile Me, did have a gallery option, but did not have the direct upload integration like Photo Stream (you had to manually post images).
Comment: This answer is no longer up to date and hasn't for quite a while. icloud.com provides web access to photos.
Answer: iPhoto for iOS (but so far not Mac) can create galleries (called Journals) on iCloud which you can then share. Although you have to do this manually, and it doesn't operate on the photo stream automatically so this doesn't do exactly what you're asking about. But I mention it because you might find it helpful.

iCloud access through browser


How do I disable/restrict apps from updating automatically (Chrome iOS)?

Question: I'm having an issue where an older version of Chrome iOS 43 is being updated to do Chrome iOS 50. I think iOS is doing this automatically in the middle of the night. I hadn't touch the iPhone 6 since yesterday afternoon, but this morning I noticed Chrome iOS updated to the latest version. I need to use Chrome iOS 46 or older because Chrome iOS 47 and newer changed over to some different engine. The Data Saver feature is gone and I rely on it to keep my monthly bandwidth allotment in check. There must be a way to restrict updating apps automatically?
Answer: Turn off automatic updates: Settings app > iTunes & App Store > Toggle Updates to off.
You will have to manually choose to update apps in the future from App Store > Updates tab.
I'm not sure that Google got rid of Data Saver though. How to enable it on Chrome for iOS might be a different question you can ask.
Another couple things you might want to consider are using Safari with an ad-blocker. Adguard is the one I use and it prevents ads from loading in Safari, so browsing uses less data. And the other thing would be to get a data tracking app (I use smartapp) so you can have a better sense of how much data you have and are using.
And of course, use WiFI where available and make sure settings in other apps don't load as much content over cellular.
Comment: D'oh. I was looking in Restrictions for some reason. I think in Chrome iOS 48 and on, [Google switched to WkWebView](http://web.archive.org/web/20160527195009/http://arstechnica.com/apple/2016/01/new-chrome-for-ios-is-finally-as-fast-and-stable-as-safari/) which is the same one Safari uses. Before Apple restricted third party browsers from using that engine.  I just like having Chrome history all my computer, laptop, tablet, and smartphone in one place. Thanks for your suggestion regarding Safari and Ad Blocker. That might be the better way to go to save data.
Comment: You can have browsing data synced cross desktop and mobile versions of browsers. Safari syncs over iCloud, Chrome syncs over Google. Firefox also does something similar.
Comment: I have an old version of Safari on Windows 7, but I don't believe Apple is updating Safari for Windows any more. Apple is too platform centric and not willing to invest like Google has with Chrome browser on Mac OS X and iOS.


Mac OSX email message report

Question: How can i get a message report that tells me that an email i sent has been received and opened?
Answer: You can enable a Read Request Receipt in Apple Mail, so if the receiver client support it, you'll get a "Read Receipt" back.
It is possible to add these headers to to outgoing mails:

"Disposition-Notification-To" (Read Request Receipt)
Bcc
"Reply-To"

To make Apple Mail request a read receipt for every message you send:

Open Terminal.
Type "defaults read com.apple.mail UserHeaders".
Press Enter.
If that command returns "The domain/default pair of (com.apple.mail, UserHeaders) does not exist":

Type

defaults write com.apple.mail UserHeaders '{"Disposition-Notification-To" = "Name <email@address>"; }'
replacing Name with your name and email@address with your email address.

The complete line could read defaults write com.apple.mail UserHeaders '{"Disposition-Notification-To" = "FirstName LastName <firstname.lastname@example.com>"; }'

And to add one of the other headers you just add it to the line - then the line could read like this:
defaults write com.apple.mail UserHeaders '{"Reply-To" = "ReplyFirstName ReplyLastName <firstname.lastname@example.com>"; Bcc = "BccFirstName BccLastName <firstname.lastname@example.com>"; "Disposition-Notification-To" = "FirstName LastName <email@example.com>"; }'
Answer: You can't as the receivers client has to send back information and most clients do not do that, ie they can read the email without marking anything In the RFCs covering mail there is nothing that must be done to provide this functionality. You can probably tell that the mail has reached the recipient's mailbox but that is it.
Comment: Indeed, for privacy reasons many people (myself included) prefer not to allow the sending of such return receipts. If I see an incoming message late at night but decide not to answer it until the next day, I don't want the other party to be aware of that decision.
Answer: The one way you can "sort of" get a return receipt like you're asking for is IF the system Mac Mail is connecting to has the capability.
For example, you can get request receipts with MS-Exchange. If you setup Apple Mail to communicate with exchange – you probably also have access to a web-version for your email system, which will probably let you setup read receipts for the messages you send from the web client.
But no, if you're just using Apple Mail with a typical POP, IMAP or Mobile-Me setup you're not going to have access to a read receipt feature.

Mac OSX email message report


Map coverage for CenturyLink High Speed Internet?

Question: Does anyone know where to find a map coverage that CenturyLink has for their high-speed internet? I am asking specifically in Colorado.
Answer: Here are two solutions for you, but nothing out of the box. They both require some work to get exactly what you are asking for.
Fixed Broadband Deployment Data from FCC Form 477's
latest iteration is through 2016-06; here is Colorado's:
CO Fixed 2016-06
You are going to have to filter out all providers except for Centurylink, and then match the census blocks with a crosswalk so you can map it.
National Broadband Map (NBM) has data from 2014 and back.
Colorado's NBM 2014 Shapefile
This will need to be edited so that it only shows CenturyLink's data.
Answer: There is an interactive map from CenturyLink (from any other source it'll be be hard to find official data)
https://www.highspeedinternet.com/co

To get the underlying data, you may have to deconstruct javascript (I pulled this from the HTML source)
https://d1sfco99flnudn.cloudfront.net/www.highspeedinternet.com/js/2023195885.site.js
It references the Mapbox API (and Markers)


How could the land departure be recorded when re-entering the United States?

Question: I found the following answer for recording a land departure.
"A departure will be recorded if you depart via land and re-enter the United States prior to the expiration date stamped in your passport."
I wonder how the land departure could be recorded when re-entering the United States. Does it require some evidence? Please let me know it if there is any person who experienced this.
Comment: I am not a specialist of US immigration law at all and will let someone else answer but logic suggests that they can at least know you left, even if they don't know precisely when, simply because you present yourself from the other side of the border. That's probably why the text states "prior to the expiration date stamped in your passport". It's only after that date that the exact date of departure becomes material.
Comment: A general advice (again not US specific) would be to keep as much evidence as possible (travel tickets, credit card receipts showing your presence in another country, foreign passport stamps) so you can support your version of events if challenged.
Answer: It requires some explanation but it is not unusual. It was actually my toughest CBP interview so far (at about 2 minutes of questioning, so I wouldn't worry too much). Once the guy found the Canadian border entry stamp he seemed happy about it.
No documents or other information was sought from me, just a coherent explanation of how this had happened and about my travel plans. I was then re-admitted as normal for 90 days. No one has mentioned it since then but it comes up blank in my I94W travel history.
Please see also my answer to this question: Exit stamp on passport when leaving US by bus
Comment: Thank you for your reply. What's the meaning, " it comes up blank in my I94W travel history."? Does it mean that your departure record in I94W history is blank without any departure date?
Comment: @Peter No, the "departed from" field is blank, where it would normally show which port I used to exit (e.g., the one below says "NYC New York". The departure date was set to the date for my entry to Canada.


Retina monitors and old Mac Pro

Question: I have an Early 2009 Mac Pro with one DVI out, one Mini DisplayPort out, and an NVIDIA GeForce GT 120 graphics card. I'm wondering if my Mac will support retina graphics, and if so, are any of the LED monitors labeled as "4K" basically retina displays? (I'm not interested in Apple's monitors)
Answer: I am not sure about the GT120. However, per this post, yes can get full 4K resolution (3840x2160) @ 30Hz with the Radeon 5770 and an ACTIVE Mini DisplayPort to HDMI connector that supports 1.1 and not just 1.2. However, this will get you the full resolution, and not the 300dpi screen doubled "Retina" (aka HiDPI mode) experience. If you download SwitchResX it will list possible options for you.
I can confirm this worked perfectly to get both 3840x2160 and 1920x1080 HiDPI (Retina) with a Mac Pro, Radeon 5770, an Acer B286HK, and a regular mini-DisplayPort to DisplayPort cable.

Retina monitors and old Mac Pro


What features are vital for good bug tracking software?

Question: What features are vital for good bug tracking software and why are they important? What in particular is necessary for you to consider these features done right?
Answer: Simplicity.
If it's too complicated or too long to enter or sort bugs, nobody will want to use it.
Comment: Do you have any examples of what you consider too complex?
Comment: The latest product I had to use: Mantis. Way too many required steps to edit and reassign or close a ticket.
Disclaimer: the version in use had not been updated for a long time. Maybe things improved since.
Comment: Well, I've used Mantis extensively, and our version (also quite old) took two clicks to reassign a bug, and three clicks to close (plus entering a reason). So I can't really complain.
Comment: @Casebash - Bugzilla is way too complex.
Answer: Integration with SCM, so that any fixes can be traced back to the code, and code changes can be traced back to an issue. This does require vigilance to check in only code related to the issue being promoted/checked in against. i.e. no "Added feature xyz, and fixed random bugs in 4 different locations and a quick refactor of feature zyx".
Another good feature is workflow management, so that the business process is followed with the code. For example, may have a workflow path that goes something like this: Bug reported -> Triaged for priority and validity -> assigned to dev -> worked on -> assign to QA -> pass testing -> mark as closed.
Answer: Enforced ownership of bugs.  It shouldn't be possible to have an open issue that is not somebody's responsibility.  Other than that, simple is better.
Comment: Tracking items can indeed be nobody's responsibility.
Comment: How do you see that working? Could there be a time lag before it is assigned? Or would there be some way to determine who is available?
Comment: When a bug is created it's assigned to the default person who decides what to do with it (could be the project lead or project manager).
Comment: This depends on your process. If e.g. bugs are triaged on arrival, and then put into a prioritised backlog, there's no need for an owner. As a matter of fact, having an owner seems to me to be somewhat in conflict with the idea of a cross-functional team, and can introduce an artificial bottle-neck.
Answer:
Good/fast reporting capabilities. Management wants to track the bug trend.
API for automation,automated email notification, integration with source control, etc.
Answer:
custom reports: ability to quickly create and save queries of tickets, by all users not just admins. everyone likes their own view of the bugs. if this is done right, there's no need for notifications, just log in to your fave view of 'tickets on my plate'
tie in to version control: should be easy to find the code
changes associated with a ticket.
flow intelligence: the system should not allow tickets to be in
states where they'll fall through the cracks - so if status changes to
'Rejected', it should enforce assigning to someone in dev
customizable: every project is different, every team is different. some teams need 8 different statuses, some just need 3. but, the GUI should remain
simple: keep the key elements of the ticket big and
upfront and simple.  version,
headline, description, status, owner
history: this really stands out when it's done wrong (i'm looking at you, Unfuddle); so it should be pointed out.  the history of changes to the ticket need to be visible in a nice chronological log.
Answer: I find it quite important to be able to link issues (and specify a link type, e.g. Depends on).  Apart from that the usual suspects of version that the bug was found in, what version we're aiming to fix it (so we can drive road maps), an estimation field is good for project/agile planning.
Nice to haves for me are voting from the public, the ability to notify users of changes to the issue and having a fairly flexible system of categorizing the issues.
In fact pretty much everything that JIRA supports out of the box :)
Answer: Any feature that does a task for the programmer. Shouldn't it really be part of the IDE? There's the list of bugs. Pick one to work on and all of the status and time stamps are taken care of. The code changes are linked. Required tests are associated. Check it as fixed, update the status and let everyone else know about it.
Comment: Can be part of the IDE but should also have a part that can be accessed without IDE because there might be others involved in the project who don't use the IDE.
Comment: @Victor Hurdagaci - good point. It needs to be accessible to everyone who needs it in an appropriate form.
Answer: Hability to identify similarities on tickets that already closed.
Could be used data mining algoritms, perhaps.
Answer: Powerful Query
The bug tracking software should help to manage the projects by enforcing rigorous development process at each stage of issue resolution.
Comment: This answer could be more helpful if you gave more detail.  Also see the FAQ at http://programmers.stackexchange.com/faq for advice on how to best answer questions with not too little, not to much information.


Sony alpha 7 battery for timelapse

Question: I'm going to buy Sony a7rII anytime soon, and I would like to use it for timelapse and landscape photography. I've read that a7rII have cca 300 shots per battery, would it be possible to use external battery pack like for charging mobile phones? Camera costs 3500€ alone, I want to save money on external dependecies like this as much as possible.
Comment: I don't have an answer but a caution. It seems the battery drain is tremendous and actual shots on a single battery is far less than claimed. In any case, I felt the body (not mine but a friend's) get very hot on continuous usage. Depending on how long a timelapse your needs are, this may be an issue even with an external battery pack.
Answer: I guess the best solution is a USB power bank. Your camera should be able to shoot and charge simultaneously (unlike some other models like a6000)
Video here:
https://www.youtube.com/watch?v=EO4f-WOotfM
Answer: First of all, when it means 300 shots, it means the average time to compose, focus, and shoot the photo.  The sony A7RII is not meant for long time shooting.  Normally, any battery bank with a USB cable connected to the Sony camera should work.  Even if the battery bank lasts long enough, heating may shorten the length that you can shoot timelapses.
Comment: I got the impression that the OP's mention of ~300 shots per battery was imply that 300 wasn't enough for their timelapse needs, hence their question. At least, that's how I read the question.

Sony alpha 7 battery for timelapse


Euphemism for fundamental conflict between two things?

Question: Is there a euphemism for, within a given scenario, the fundamental conflict between two things? Almost akin to 'double-edged sword'. But that would not be right. I can clarify more. Open to any thoughts.
Comment: If you _can_ clarify more, than you _should_ clarify more. Questions with more information, background, and context are generally more appreciated. More importantly, others are less likely to put a lot of thought and time into answers that are ultimately unhelpful to you, because they were going down the wrong track.
Answer: Caught between a rock and a hard place.
Is a good euphemism for when you're stuck in a situation or conflict where resolution is difficult to see; & the outcome well frankly just stinks.
I thought of a couple more:
stuck between the devil and the deep blue sea
got myself in a real catch-22 here
Hope they help :-)
Answer: There are numerous possible euphemisms and metaphors for the situation you describe, but which would suit is very context dependent.
Some possibilities are:

irresistible force meeting an immovable object
irreconcilable differences
caught between Scylla and Charbydis
oil and water
cats and dogs
fire and ice
polar opposites
mortal enemies

And, in the US, there is always

Congress
Answer: The euphemism applicable is "Equilibrium".
Equilibrium is achieved when two or more competing or conflicting forces come to an involuntary lock where the forces balance each other out.
A dynamic equilibrium is when active conflicts are ongoing with constant loss and gain of ground.
For example,

Godfather to lieutenants of two of his conflicting factions:
  So, what have you both achieved in your disagreements?
Gang lieutenant:
  We have come to an equilibrium.
Godfather:
  You meant that your losses balance his losses in the number of men dead and maimed?

The other euphemism applicable is "evolutionary pressure". Evolution can be perceived as a process where the most matchable and adaptable to an environment survives. It is then seen as a conflict between producing superior species at the cost of elimination of others.
Yet another applicable euphemism is "Symbiotic relationship". Rather than saying

They are feeding off each other.

We could say,

Their conflict is a symbiotic relationship.

Combining the three, we could say,

The gangs are in a symbiotic relationship. Their conflicts present evolutionary pressure to improve their ranks by mutually helping each other cull off the weak members. It is the perfect pyramid scheme where equilibrium is attained, resulting in the advantage of having contributors who would no longer be around to clamour for a return of their investment.
Answer: I think 'antipathy' is the word you may be looking for.


Misner String Singularity

Question:
In correspondence to AdS black hole solutions, what does it mean by Misner string singularities? And when there are no Misner string singularities, what does this mean in terms of curvature singularities and event horizons and the black hole in general?
A related question (as far as I'm aware), what do we do if our solution contains closed timeline curves (CTCs)? Should we really only consider cases when our solution doesn't contain closed timelike curves and strictly impose restrictions on our parameters that ensure this?
(While on this topic, an elementary question, why does $g_{\phi \phi}<0$ imply CTCs, if we're in hyperbolic 4d space?)
Comment: Comment to the question (v3): Consider adding some references to make the question more accessible to a wider audience.
Answer: If you construct your metric in such a way that $\phi$ is a killing vector generating an axisymmetry of the spacetime, and there is a value of the other three coordinates where $g_{\phi\phi} < 0$, then you have a timelike killing vector generating an axisymmetry.  The curve traced out by this vector will then be a closed timelike curve by construction.
We tend to throw out solutions containing closed timelike curves as unphysical, because they break causality.
I haven't heard the term "misner string singularities" before, but I assume your authors are referring to a cosmic string spacetime, which will have naked singularities.  You can derive a rudimentary version of this by going through the schwarzschild derivation, but assuming cylindrical symmetry rather than spherical symmetry.
Comment: So we really want to enforce $g_{\phi \phi}>0$? And a paper I have here, $\text{Integrability in conformally coupled gravity: Taub-NUT spacetimes and rotating black holes}$ says the following: "the radial coordinate can be extended to range from $-\infty$ to $\infty$ starting and ending at a hyperbolic slicing of AdS. In this way the metric has up to four Killing horizons, but no space-time singularity whatsoever". Honestly, I really don't understand what this means. I mean, I'm assuming there is no value of $r$ (radius) s.t. the metric blows up.
Comment: Sorry, forgot to tag you in my comment. I feel like you may be able to help me with the previous comment?

Misner String Singularity


Make ahead Chicken Piccata

Question: I have a recipe for Chicken Piccata my whole family really likes. We are having a couple guests over tomorrow, and I'd like to make this recipe, but make it ahead. The guests are people we don't know personally, and it would be awkward to be cooking when they arrive. There is no baking/oven element to my recipe (just saute chicken, keep chicken warm while deglazing pan/making sauce, return chicken to pan to thicken sauce and absorb flavor of liquid, remove chicken, add some butter to sauce, add pasta to sauce and serve with the chicken). I'm worried that if I make it ahead, it will dry out the chicken/pasta. Any tips to make it work?
Answer: I don't think it is awkward to cook for your guests.  After all, they are coming to dinner, right?
Anything you do here to prepare ahead will be a bit of a compromise.  It won't be quite the same, but it shouldn't be dried out.
In any case, if you wanted to streamline, you could cook the chicken earlier, before your guests arrive, then chill. Be sure that you don't over cook your chicken, especially if you are using breasts.  Don't go over 160 F.  Leave the pan on the stove, you will use the brown bits for the sauce later.
You can also cook the pasta to about two minutes short of the package directions.  Remove from boiling water to ice water to stop the cooking. Then drain and refrigerate. Don't discard the pasta water, you can use that later while finishing the sauce.
This approach will work best if the chicken is sliced. It will slice more nicely after it is chilled.
When your guests arrive remove your ingredients from the refrigerator so they begin to warm up.  When it is time for service, heat the pan that the chicken was cooked in until it sizzles.  Use the pasta water to de-glaze...using a bit more water than normal. Add the chicken and stir for 30 seconds. Add the pasta to the pan, with a little more pasta water, to re-heat. Add your butter and any other ingredients. If there is no liquid in the pan, add more pasta water.  You should see it bubbling.  Stir that around for one minute, but this should take no more than two to three minutes to avoid over cooking your ingredients.
If you are well organized, and don't over cook the elements in either the prep step or the re-heat step, it should work.  This assumes the chicken and pasta are mixed.  If they are not, you could reheat the chicken in a separate pan (maybe a steam set up?), or better yet, if you have the tools, this would be an excellent application for sous vide.

Make ahead Chicken Piccata