What exactly is meant by the "Gaussianity" of CMBR?

Question: What does it mean when we say that the CMBR is mostly gaussian? What are non-gaussianities in CMBR? How does evaluation of 3-point correlation functions of the inflaton field tells us that there is non-Gaussianity?
Answer: (Updated on 27 April to expand on and justify some points in response to comments.)
@dbrane's answer conveys a lot of the flavor of the subject correctly, but I'm sorry to say that it's not right in detail. Because there's plenty of room for confusion here, I'm going to spend quite a bit of time on the mathematics before saying anything about the physics or cosmology. Sorry about that. Feel free to skip to the bottom if you want.
Mathematics.
The definition of Gaussian in this context actually goes like this:

A function $g$ is Gaussian if the
  $n$-tuple $(g({\bf x}_1),g({\bf x}_2),\ldots,g({\bf x}_n))$ is drawn
  from an $n$-dimensional Gaussian
  distribution for all $n$ and for all
  choices of ${\bf x}_i$.

That is, if you look at any one point, that the value at that point is drawn from a Gaussian distribution. If you look at any two points, the values are drawn from a bivariate Gaussian distribution (possibly with correlations), etc. The above is my phrasing, but it's equivalent to things you'll find elsewhere, e.g., Wikipedia.
That definition is kind of a mouthful, but there's not much I can do about it: it's the way it is!
Before digging into the subject in more detail, it's worth defining one additional term, statistically homogeneous random fields. This just means that the statistical properties are unchanged if you slide all points over by any given amount. For instance, the average value $\langle g({\bf x})\rangle$ is independent of ${\bf x}$ (and indeed so is $\langle g({\bf x})^k\rangle$ for any $k$). Moreover, $\langle g({\bf x}_1)g({\bf x}_2)\rangle$ depends only on the difference ${\bf x}_1-{\bf x}_2$, and so forth. We often assume that the fields in cosmology have this property, because we think that, on average, the Universe is the same everywhere.
In addition, we also often assume that the statistical properties are invariant under rotation -- e.g., two-point correlations depend only on the magnitude of ${\bf x}_1-{\bf x}_2$ and not on its direction. The latter property is called statistical isotropy.
For the next little while, I'm going to focus on mathematical points that don't really depend on how many spatial dimensions we have, so for simplicity I'll work only in one dimension. In that case, of course, there's no such thing as isotropy. (By the way, I'm also going to start abbreviating "statistical homogeneity" as just "homogeneity.")
Before proceeding further, let me note explicitly that Gaussianity and statistical homogeneity are independent properties: neither one implies the other.  For example, suppose that $g$ is Gaussian and homogeneous, and define another random field $h$ by setting $h(x)=[g(x)]^2$. Then $h$ is homogeneous but not Gaussian. (The pdf at any point is not Gaussian, for instance.) On the other hand, if we define $h(x)=xg(x)$, then $h$ is Gaussian but not homogeneous. (For instance, the variance $\langle h(x)^2\rangle$ depends on $x$.)
The nice property that dbrane mentions, namely that the Fourier transform of $g$ has no correlations,
$$
\langle \tilde g({k_1})\tilde g({k}_2)\rangle=P_g({k}_1)\delta({k}_1+{k}_2),
$$
is actually a consequence of homogeneity, not Gaussianity. (This property means that each Fourier mode $\tilde g({k})$ is uncorrelated with the others.)
This one's actually not hard to prove. The key is to think about the correlations between two points $x$ and $x+y$: $\langle g(x)g(x+y)\rangle$. Writing both of the $g$'s as Fourier integrals, we have
$$
\langle g(x)g(x+y)\rangle=
\int\int\langle\tilde g(k_1)\tilde g(k_2)\rangle e^{i(k_1+k_2)x}e^{ik_2y}\,dk_1\,dk_2.
$$
Let me call the quantity on the left $G(x,y)$. This equation shows that the Fourier transform of $G$ with respect to both variables is given by
$$
\tilde G(k_1+k_2,k_2)=\langle \tilde g(k_1)\tilde g(k_2)\rangle.
$$
Homogeneity implies that $G$ depends only on $y$, not $x$, so $\tilde G(q,q')=0$ for all $q\ne 0$. Therefore $\langle\tilde g(k_1)\tilde g(k_2)\rangle$ is nonzero only for $k_1+k_2=0$. That proves the desired result.
If you're lucky enough to have both homogeneity and Gaussianity, then the "power spectrum" $P_g$ is a complete description of the statistical properties of $g$. But you have to assume Gaussianity in that argument; it doesn't follow from the assumption of uncorrelated Fourier modes. The simplest cosmological models predict both homogeneity and Gaussianity, so people often forget which useful properties follow from one as opposed to the other.
Digression: Other definitions found in the literature.
In the comments, a couple of people have pointed out quotes from very well-respected cosmologists (Liddle & Lyth, Komatsu) contradicting what I said and defining Gaussianity as uncorrelated Fourier modes. These folks are great cosmologists, but they're just wrong on this. I guess I can't expect you to take my word for it, so let me try to convince you in a couple of ways.
First, let me point out that Gaussian random processes and Gaussian random fields exist in many areas of applied mathematics, and the definition I gave is utterly standard everywhere else. (In case you're wondering, one tends to say "process" in one dimension, especially when you want to think of that one dimension as time, and "field" in 2 or more dimensions.) Wikipedia confirms this, as do plenty of other sources.
Of course, sometimes people in one discipline use a term differently from people in all other disciplines. Maybe cosmologists are doing that here? That turns out not to be the case. For instance, this paper is one of the ones that started the whole idea of considering Gaussianity in cosmology, and it uses the standard definition. Perhaps even more convincing is the fact that the main form of non-Gaussianity that cosmologists try to test these days is called local non-Gaussianity, which is defined as
$$
\Phi({\bf x})=\phi({\bf x})+f_{NL}(\phi({\bf x})-\langle\phi\rangle)^2.
$$
Here $f_{NL}$ is a constant, $\phi$ is a homogeneous Gaussian random field, and $\Phi$ is the physical field to be measured. The field $\Phi$ has uncorrelated Fourier modes (by the proof I gave above). So if "uncorrelated Fourier modes" were the definition of Gaussianity, then this field would be Gaussian. But if you talk to cosmologists working in the field, you'll find that every single one knows that this field is non-Gaussian -- in fact, it's regarded as the very archetype of non-Gaussianity. (Here's one example out of many I could have chosen.)
By the way, the error these folks have made is quite common. I think that there are several reasons.  The main one is that the hypothesis of uncorrelated Fourier modes does imply approximate Gaussianity by a sort of central limit theorem argument, if some additional assumptions hold. Essentially, whatever quantities you're calculating have to have comparably-big contributions from many different Fourier modes, so that non-Gaussianities get "washed out." Back in the old days, people were willing to make that assumption, but when you're actually trying to measure non-Gaussianity, this is precisely the level of approximation you're not allowed to make.
Another reason is that everyone learns the "standard" (homogeneous, isotropic, Gaussian) picture of cosmological perturbations really well, then they forget which properties of the standard picture depend on which of the hypotheses. And of course once something is incorrectly stated somewhere, it propagates.
Physics.
As far as the physics is concerned, the main point is that some standard theoretical models, such as inflation, predict that the CMB (among other observables) should be Gaussian, as well as homogeneous and isotropic. If this is true, then the power spectrum, which I called $P_g(k)$ above, is a complete description of the statistical properties of the field. To define a Gaussian distribution, you just need to specify its first two moments, i.e., the mean and the variances & covariances. The mean is zero (mostly because we define it that way -- the observables are fluctuations about the mean). With these assumptions, there are no correlations in Fourier space, so all that leaves is the variances of the Fourier modes. That's what the power spectrum is.
Some slightly more exotic cosmological models (fancier versions of inflation as well as non-inflationary models) predict non-Gaussianity. One form this might take is nonzero 3rd-order correlations: things of the form $\langle g({\bf x}_1)g({\bf x}_2)g({\bf x}_3)\rangle$ should be zero in a Gaussian theory but not in a non-Gaussian one. That's the reason people look for 3-point correlations. If you look for them in position space, you call the thing you're trying to measure the "3-point correlation function." If you try to measure it in Fourier space, you call it the "bispectrum."
But even if there are no 3-point correlations, things might still be non-Gaussian. Gaussianity is a very specific set of mathematical properties, and there are infinitely many ways to be non-Gaussian. As a result, there are tons of proposed tests for non-Gaussianity, all looking at completely different things. For instance, a form of non-Gaussianity that was symmetric under a sign flip (the statistical properties of $-g$ are the same as those of $g$) would have no 3-point correlations, but it could still be non-Gaussian. You could search for that by looking at 4th-order correlations, although at some point thinking of things in terms of these correlations is not the best way to do it.
As a result, there are a bewildering variety of completely different tests people use. To cite one more-or-less randomly chosen example, people calculate the Minkowski functionals of excursion sets in CMB maps. The connection between Minkowski functionals and non-Gaussianity is not obvious, but the point is just that in a Gaussian process you can predict various properties of the functionals, and if the observations give different answers, that's non-Gaussianity.
Comment: Thanks a lot for that. I have to add however that Lyth and Liddle (in Primordial Density Perturbation) say things very differently, although this might only be a quibble about definition. For example, they start saying "A gaussian random field may be defined as one whose Fourier coefficients have no correlation except for the reality condition" and later on come to the conlcusion that "gaussianity implies statistical homogeneity". I'll read both your answer and their chapter again to sort things out in my head!
Comment: Also, clearly in this case, you are an exception to that general rule I made up in the comments on my answer :P +1
Comment: Thanks for your response! I'll have to go read Lyth and Liddle. I have a lot of respect for them and their work, but that's definitely not right.
Comment: I saw Liddle and Lyth and the way dbrane defined Gaussianity is quite correct (at least according to Liddle and Lyth) however, I have issues regarding dbranes comment "Fourier modes being uncorrelated is precisely equivalent to statistical homogeneity & isotropy, and is completely independent of Gaussianity." Komatsu's [review article](http://arxiv.org/abs/astro-ph/0406398) clearly says the non-correlated Fourier mode is a result of Gaussianity!
Comment: Are you referring to this quote? "Within this approach, the primordial density perturbation is Gaussian; in other words, its Fourier components are uncorrelated and have random phases." This quote is kind of confusing. If "in other words" is meant to signify logical equivalence, then it's just wrong. If what he means is that Gaussianity implies the other conditions (but not the converse), then it's true as long as there's an additional implicit assumption of homogeneity (which there probably is). You don't need Gaussianity to conclude "uncorrelated," but you do to conclude "random phases."
Comment: It's clear that I should expand my answer and justify some of the things I've been saying. I'll try to get to that later today.
Comment: No, the quote I took was from Section 6.3.1 (Pg 88) where they define a Gaussian field using the correlators. What I gathered from that section is that Gaussianity is *defined* based on the correlator structure.
Comment: @dbrane -- I should've been clearer. In my previous comment I meant to refer to the Komatsu review article that Debangshu linked to.
Comment: Edits done. I hope this version lays out the key points more clearly, although it's grown to be quite long! Comments extremely welcome.
Comment: @Ted: very nice read. Thanks for the write-up!
Answer: The physical meaning of gaussianity is that the CMBR is as random as possible, with no correlation at all between the independent fourier components of the fluctuation field. Each fourier mode of the inflationary perturbations that gave rise to the CMBR anisotropy evolved as independent uncoupled harmonic oscillators (albeit with a time dependent frequency).
Gaussianity of any cosmological variable $g(\textbf{x})$ (say, the scalar field perturbation $\delta\phi(\textbf{x})$ or the density $\rho(\textbf{x})$) is defined by the structure of the two-point correlator. If it has the form $$\langle g_{\textbf{k}}g_{\textbf{k'}}\rangle=(2\pi)^3\delta^3_{\textbf{k}+\textbf{k'}}P_g(k)$$ then
$g(\textbf{x})$ is said to be Gaussian, where we've also assumed isotropy so that the power spectrum depends only on the magnitude $k$. (Homogenity means that $\langle g_{\textbf{k}}\rangle=0$). The 3-point-correlator (and all odd point correlators) vanish. This is the minimal possible correlation that you can have in a stochastic field. You're allowed to have any form for the power spectrum $P_g(k)$, although inflation predicts a nearly scale invariant spectrum, with it depending very weakly on $k$.
If you're wondering where the "gaussianity" actually comes in, it can be shown that the probability distribution for $g(\textbf{x})$ at any given point actually follows an exact gaussian: $$\textbf{P}(g)=\frac{1}{\sqrt{2\pi\sigma}}\exp{(-\frac{g^2}{2\sigma^2})}$$ So, for things like the scalar field, density and curvature, zero-deviation is most likely and higher fluctuations are exponentially suppressed.
You can start introducing additional correlations through the 3-point-correlator by making it non-zero and then you will have destroyed the gaussian structure of $\textbf{P}(g)$ above, hence it's called non-gaussianity. Such deviations are predicted by some models of inflation, but none have been observed so far. Tighter constraints on cosmological parameters from experiments like Planck should start coming in soon.
Chapter 6 of Lyth and Liddle's Primordial Density Perturbation is a good reference for this.
Comment: The temperature anisotropy of radiation and its power spectrum can be calculated from the scalar metric perturbation (predicted to be Gaussian by inflation, just like the scalar field perturbation and the density perturbation). This is done in great detail in Chapter 9 of Mukhanov's *Physical Foundations of Cosmology*.
Comment: Thanks a lot! I still do not get how we are going to connect the experimental observation with the data. In experiment, we measure $\langle T(\hat{n})T(\hat{n^{\prime}})\rangle$ while theoretically, we are calculating $\langle \delta \phi_{k} \delta \phi_{k'}\rangle$. How should we relate these?
Comment: +1 I've heard a whole semester's worth of seminars on nongaussianity, and no one explained it as nicely.
Comment: @Willie Wong  I'm learning about non-gaussianity. As a general rule, people who've just learnt something tend to explain things better than people who've been familiar with the same thing for a long time :)
Comment: @Ted Bunn Yes, sorry about that, isotropy was implicitly assumed when I wrote $P_g(k)$ as a function of the magnitude $k$ alone. And homogenity also needs to be spelt out by stating that $\langle g_{\textbf{k}}\rangle=0$. But given just those conditions, you still have a Gaussian field -- despite the fact that Gaussianity doesn't require homogenity and isotropy -- is that what you meant?
Comment: I'm sorry to rain on the parade, but although you've got some of the ideas right, this is not correct in detail. I'll post why in a separate answer, as it's too long for a comment.
Comment: @dbrane -- no that's still just not correct. The statement about the Fourier modes being uncorrelated is precisely equivalent to statistical homogeneity & isotropy, and is completely independent of Gaussianity.
Comment: Ted Bunn is right that uncorrelated fourier modes is not equivalent to Gaussianity. As I understand it, Gaussianity just means that the values of the field at any given set of points are distributed according to a multivariate Gaussian. This is equivalent to saying that the two-point correlation function is all you need to describe any higher-order correlations (according to Weinberg).
Comment: Great answer! I've started to learn about CMB and your answer is quite helpful. However, when you say "_with no correlation at all between the independent Fourier components of the fluctuation field_", what do you mean by a fluctuation field? @dbrane


How to proceed if employer ends the job for inappropriate reason?

Question: When I graduated from my school, a company hired me as an intern. They had potential to hire as a full-time, but they wanted to see how I perform before hiring for full-time. I had several interviews for intern position, and then they offered me a 3 months internship. After 3 weeks suddenly human resource person gave me a check of 5 weeks pay and told that my skills are different and I should another position.
3 weeks is a pretty short time and no one can judge the engineers' performance in that time. I had to perform for 3 months and then they had to make a decision and that was the standard way.
I am sure it's unfair with me, and I should contact department of labor to know if an employer can treat interns like that. Internship is a program for skill enhancement, and if employer is not going to hire the intern as a full-time, that doesn't mean they would end the internship.
I wanted that employer to pay my rest of the contract period pay because it was a 3 months internship, but they told that I didn't perform well. Engineers can't be judged in 3 weeks and that's why I was given 3 months.
Is there any govt agency that can help me with this matter? I understand that it's against corporate ethics.
That employer is based in bay area.
Comment: I would strongly suggest that you take a look at the FAQ for what makes a good question. What you've asked is more of a rant rather than a concise question.
Comment: No-one can tell you if there's a government agency or not without knowing what country's government might have authority in your situation. Please add a location tag.
Comment: I am sorry, but to put it bluntly, if you do not think an Engineering manager can tell within 3 weeks if you are qualified to perform at the level they need, then you already have demonstrated you are not qualified.  Things like evaluation internships and 30 or 60 day probationary periods would be meaningless if such evaluations could not be made that quickly.  From my experience, paying you 5 weeks for 3 weeks of under-performance is very generous.
Comment: What does your contract say about termination?
Answer: Most likely, you were hired as an at-will employee. That means, you can be dismissed with reason (in this case, underperformance would be a valid reason) from your employer. Now unless your employers openly discriminated you as a member of a protected class, there is no other means left for you. Consider filing for unemployment if you qualify.


Shunt voltage direction circuit

Question: I need to know which terminal of a shunt is higher, ie whether I'm charging or discharging my 12v battery bank. The voltage difference is very small (max 74mv) since the current flowing may be tiny, so I'd assume no diode drops, and high impedance to not throw the current readings off. What comparator circuit would work here? Output could be a simple LED, lit when discharging, say.
Answer: If you just need the direction you need to measure the polarity of the voltage at the shunt. Because you want the get positive and negative readings you'll need a negative supply voltage for your measurment device.
So you need to construct a comparator that switches it's output around 0V (add some hysteresis to prevent it from oscillating due to noise).
If you absolutely can't have a negative supply we need to find more creative solutions (where I can imagine several). But with most of those solutions there will be a window just around zero current where you can't be sure what the direction of the current is.

simulate this circuit – Schematic created using CircuitLab
This is just a quick and dirty Idea. I'm not even sure if it would work...
Answer: At this point I am assuming the Shunt is in the Plus side. I have done things like that, I prefer to use a hall effect sensor. Reason to use an Op Amp or Comparator you need to construct additional circuitry such as voltage dividers which will degrade the sensitivity or power the device with a higher voltage then what you are measuring. If not the input to the comparating  device will be above the rail which they do not like. Take a look at the AS712, it was designed to do this. If it is not sensitive enough other similar devices should be available. There is a lot of information on this device, it is quite popular with the Arduino crowd.
Comment: Thanks for this. There's an existing shunt, on the negative, and a digital current readout, which for some reason doesn't include polarity/direction, hence if possible I'd like to add only that functionality
Answer: Use a ± 75 mV, 'centre-zero', moving-coil meter to indicate charge / discharge.

Shunt voltage direction circuit


What do you call the act of "misusing" metaphors?

Question: What do you call the act of "misusing" metaphors or using it in a way that's not accepted or considered wrong by most authors. I am trying to find the word, because there are no clear rules of how to use metaphors, except some people often agrees that metaphors used in a certain way is bad or improper or bad style.
Comment: An assault on good taste, it'll get ya 3-5 in the big house.
Answer: I've typically heard the word "malaproper" or "malapropism" are the correct word to use for a misuse of a metaphor or other type of sentence (simile, allegory), though I may be wrong.
Answer: When a second metaphor is used very soon after another, care should be taken to ensure that there isn't a ludicrous clash:

If there is a spark of pity in your hearts, water it and let it grow.

Such mangling of the language is termed mixed metaphor (see Nordquist's article at ThoughtCo for other comical examples).
The term is sometimes extended to cover poor choice of metaphor:

John's a tiger; don't mess with him!
??That lion's a tiger; don't mess with it!

Overblown, pretentious metaphors are sometimes used:

This small car is a Pegasus soaring above the competition.


Is it possible to find heat flux without emissivity value?

Question: In this question there is a value given for absorptivity of infrared radiation however in order to work out a value for heat flux emitted from the solar panel in order to answer part (a) surely I'd need a value of emissivity? I have been stuck on this and have no clue how to work part (a) out without a value for emissivity.
Answer: You don't get the the emissivity coefficient because it is already factored in the problem. You have a constant temperature of $71[^oC]$ on the external surface, and this is explicitly stated as a steady state problem.
So you only need to consider other types of heat transfer (e.g. conductive).


can i install windows phone 7 on HTC desire?

Question: I own a android phone, desire . I wish to install windows phone 7 on it .
 Can I do so ? and if the answer is yes, how ?
Thanks
Comment: If you had a Desire Z it would be easier since the reverse is quite doable: http://android.stackexchange.com/questions/6849/can-i-install-android-on-my-non-android-device.  That said, I think this is off-topic since you're asking about WP7 and not Android. We can't help you with that.
Answer: Nope you can't. Android phones are a bit "blocked" for other OSes to be run and installed on the device... By the way the first approach for this can be found at HD2 ToolBox and Hot Bootloader, which may help developers to build boot some other OSes on top of Android.
Different from the Windows Mobile era, that for example my HTC Touch Pro2 can run Android(fully featured) and Ubuntu(with some restrictions), not to mention al those OSes that have been ported to the HTC Leo(HD2).
Comment: i saw that you can install windows 95 on Desire. Why is WP7 so different ?
Comment: You can install Win95 on a x86 emulator for Android. That's the difference...


How do I clear cookies from the Twitter app internal browser on iPhone?

Question: Just to clarify, I've tried cleaning the Safari cookies with no success.
Answer: I don't believe there is anything you can do sans uninstalling and reinstalling the Twitter app.   Each application that uses the WebView has its own cookie store.
A developer can programmatically remove cookies.  So the Twitter app would need to give you a way to clear cookies which I don't think it does.
Answer: In the Twitter app, open Settings and privacy. As of August 2017 and version 7.4, it is accessed by tapping your profile picture in the top-left corner.
Now go into Data usage → Web storage and select Clear all web storage. This will delete your Twitter cache, cookies and logins.
That action does not affect pictures, videos and vines attached to Tweets. Instead those are deleted under Data usage → Web storage → Clear media storage.
Answer: Go to advanced settings under safari.
See twitter weasel's data
Swipe left and delete
Comment: We are talking about clearing the internals of the app, not the web version.


Editing questions which are on hold

Question: Is it worth it to try and edit questions which are on hold or should people assume that the moderators are working on them?  Is the answer the same regardless of how long ago the question was asked?
Answer: If a question is on hold, editing it would be of big value for us. Only a few moderators are taking the time to edit them. Most times the question is on hold, because the moderators saw no way to improve it.
So yes, please edit the question, even if it is a very old one.
Comment: Especially for questions which are on hold for being unclear or off topic we (moderators) *need* for OP to edit, as we would just be guessing as to the intent.

Editing questions which are on hold


Does Nektar Impact LX49+ MIDI keyboard work with LMMS?

Question: I am considering purchasing a Nektar Impact LX49+ MIDI keyboard, but before I do I want to make sure it will work with the Linux DAW called LMMS. Have any of you used this keyboard with lmms? Did you run into any problems that you couldn't fix? Thanks.
Answer: The Impact outputs MIDI. LMMS uses MIDI.
MIDI is a pretty good standard, and any controller presented to the interface can be assigned in LMMS.
The Using MIDI part of the LMMS documentation is very useful and explanatory.


Dark L in unstressed syllables

Question: I was wondering. I was reading in one forum about the dark L someone said about how you can also have a dark L in an unstressed syllable so a word like only (ˈoʊnli)  will actually have dark L.
Can someone enlighten me a little.bit.more about this please?
However, a word like maleficent wouldn't have a Dark L, it'll have a Light L, since the Letter L  Is the stressed in the word.
I need a little help about unstressed L's being a Dark L.
Comment: Dark l as in _dull_; bright l depending on accent, _million_. Stress has less of a role to play than vowel environment.
Comment: There are many dialects of English that either have no dark l at all (most Irish dialects) or only have dark l (many American dialects). Presumably you're excluding those dialects from your enquiry here?
Answer: To start with, I would say not to worry about this too much, as I think it would be hard to perceive the difference in this position. For me, "dark l" (i.e. /l/ with a back articulation, phonetically transcribed as [ɫ]) is most noticeable in its effect on the pronunciation of a preceding vowel, so when I try to pronounce the /l/ in a word like "only" as dark vs. light, I can't hear much difference.
It seems somewhat plausible to me that /l/ in a word like "only" might be dark, although it certainly is light in many accents. If you're getting into the phonetic details, you might want to know that according to the phonetician Jack Windsor Lewis, "only" is often pronounced without any [l] sound at all (see my answer to the question Is it common to pronounce 'only' as 'own-knee'?).
Different accents are known to follow different rules for the distribution of light and dark /l/. As Janus Bahs Jacquet said, there are supposed to be accents that take one of the two extreme options of "all /l/s are light" or "all /l/s are dark". And there are a number of different types of in-between rules:

For "RP" English, the rule is typically described as using light /l/ before a vowel (or before /j/), and dark /l/ elsewhere. Word boundaries are supposed to be irrelevant, so we would hear light /l/ in a context like "full of sand".
For "SBE" (which is supposed to be a modern British accent, unlike "RP") the rule may be somewhat different. One exception to the "preceding a vowel" rule that I've seen given is syllabic l: according to this web page, that would be dark in "SBE" even when a vowel follows.
Bermúdez-Otero (2013) cites Sproat and Fujimura (1993) as describing a different rule for the distribution of dark /l/ in a certain accent of American English. In this accent, word-final /l/ is always dark, regardless of whether a vowel or a consonant follows, but word-internal /l/ is light when a vowel follows. The examples given to illustrate this are "Beelik" (light l) vs. "Beel equates" (dark l).
There are accents of American English and of British English that show l-darkening in more contexts (yellow and village are the examples given). Bermúdez-Otero analyzes these accents as having a "foot-based" rule, like the rule for t-flapping. For this rule, stress is relevant: /l/ cannot be dark at the start of a stressed syllable, but it can be dark at the start of an unstressed syllable (assuming that we syllabify words like "holy" as "ho.ly").

I didn't see a detailed analysis of how this rule was supposed to apply. For t-flapping, Bermúdez-Otero says there are actually two rules involved: at the word level, /t/ in non-foot-initial position is supposed to be lenited, and then at the phrase level, lenited /t/ is supposed to be flapped when it is followed by a vowel and preceded by /r/ or a vowel. This allows us to explain why we don't see flapped /t/ in words like "guilty". If a similar two-part process is supposed to account for l-darkening, then we would only expect to see "dark" l when the preceding sound is a vowel or /r/. But it seems plausible to me that some accents might have a simple rule of darkening non-foot-initial /l/ regardless of the identity of the preceding sound.

My accent has what Bermúdez-Otero would call a "foot-based" type rule, and I use dark /l/ in angrily and daily. Based on the pronunciation of the vowel, I believe that I use light l in lowly, slowly and grayly, and sometimes in gaily, presumably because the morpheme boundary is more salient than the one in daily. I always use dark l in "-Vly" words when there is no morpheme boundary before the /l/, e.g. holy, mealy, steely, wooly.
I use dark l in words like wholly, totally, finally.
I think that I use light l in words like invisibly, unbearably.
I think that I use light l in only, although as mentioned in the first two paragraphs, it doesn't seem very noticeable.
Comment: Thank you so much!! Your answer seems really great. And. What do you think about angrily and daily, would they have dark ls for you sumelic?
Comment: Wow!! So nice of you!!!! Thanks so much this sound is kinda hard because someone told me words like darling and tulip will also have a dark L sound. I will keep on trying. Thanks.
Comment: @CarlosFernandez: Words like "darling" or "tulip" can have light or dark l depending on the accent. Since both types of l will be recognized as the same sound, I don't think you need to worry too much about trying to produce one or the other in contexts like this. It's probably OK to just go with whichever is easier for you.
Comment: I will agree on you that the dark L is very prominent in words like world, cool, involved, culture. And I will agree that in "holy" "angrily" you can somehow still hear it. However I will agree that in some words is not that prominent like in only as you stated. Also for example in regularly they will sound the same light or dark.
Comment: Interesting exposition. A small note defining light and dark 'L' would be helpful.
Comment: @Lawrence: It's a little bit difficult to give a short but useful definition of "dark l". As mentioned, different accents use it in different contexts, and it also has some different kinds of phonetic realizations. Speaking generally, it can be said in phonetic terms to have a "back" articulation, which might be described as "velar", "uvular" or "pharyngeal".  It's written in IPA with the symbol ɫ. Would it work if I just added a link to the following question? [Confusion about how to pronounce the "dark L" consonant sound](https://english.stackexchange.com/questions/220433)
Comment: @sumelic What I had trouble with was that light/dark doesn't immediately communicate the 'axis' of discrimination: clear/swallowed (*yellow* vs *paella*) or long/short duration (*let* vs *plait*), etc. The first paragraph of the [website you referenced](http://seas3.elte.hu/phono/notes/el.html) was a nice lead-in to the concept. I accept that it's hard to fully define the term succinctly, but a little clue wouldn't go amiss. I think a minimal addition would be a reference to, say, "velar".
Answer: I don't think the "l" in "only" would be dark, because the change to dark "l" depends on the syllable position of "l"; "l" is dark in the offset of a syllable, by which I mean the part of the syllable after the vowel. "Only" is divided into two syllables "on-ly", and "l" is at the beginning of the second syllable, even though the vowel of the second syllable is not stressed, so the "l" is probably not dark.
By the same reasoning, the "l" of your other example, "curly", should also not be dark, but this is less clear than the first example, because the syllable division could be "curl-y", in which case the "l" is at the end of a syllable and should be dark. In my own speech, the syllable division is "cur-ly", and the "l" is not dark, just as for your first example, but this might not be true for other people. There are two complicating factors here that might give a different result:
(1) If you take away the last vowel in the first example, you are left with "onl", which is not a possible word of English. But in the second example, you are left with "curl", which is a word, and in fact is the word from which "curly" is derived. Since syllable boundaries sometimes tend to follow the divisions between meaningful parts of words, this might cause the syllable division "curl-y".
(2) Sometimes a single consonant in English between a stressed vowel and an unstressed vowel is shifted into the preceding syllable with the stressed vowel. Since "ur" is a single stressed vowel (even though it's spelled with two letters), and "-y" is an unstressed vowel, the "l" might shift into the first syllable for this reason. That should make the "l" dark. (But that doesn't happen in my own pronunciation.)
Comment: Thanks so much greg lee. Just one.more doubt how about angrily and daily? Do they have darl ls for u?
Comment: @CarlosFernandez, I'm not sure.  My first impression is that l is not dark in either of those examples in my own speech.

Dark L in unstressed syllables


Example of Heisenberg Uncertainty Principle (energy & time)

Question: Beside momentum and position I read that Heisenberg Uncertainty can also apply to energy and time so for instance virtual particle (energy) could pop into existence but for a very brief moment (time) unlike say an electron (if we know the energy level) it will lasts for a very very long period of time, so I just wondering if there are any other more empirical examples.
Answer: The fist thing to mention is that the uncertainty relation between energy and time is in this sense different from position and momentum that in quantum mechanics time is a parameter and not a dynamical variable (like position and momentum, which depend on this parameter). Beside that, there is no intuitive hermitian time-operator $\hat T$ which is canonical conjugate to the energy-operator (the Hamiltonian, $\hat H$) such that the commutator is $[\hat T,\hat H] = i \hbar$ from which we can obtain the uncertainty relation from the expectation value of the commutator, i.e. $\Delta A \Delta B \ge \frac{1}{2} |<[\hat A, \hat B]>|$.
Since the uncertainty relation make statements about the dispersion of observables of experimental outcomes we can construct measurement schemes where the energy-time uncertainty relation come into play.
Therefore, let us consider the Einstein ''clock-in-the-box'' thought-experiment: Suppose we have a box which emits a photon through a slit and that we measure the weight of the box and can measure the time when the photon was released with the clock inside the box. Since the weight is proportional to the rest mass $m$ and by Einstein's famous fomula proportional to its energy $E = mc^2$. Here, I just want to mention that in the original discussion between Einstein and Bohr this scheme was proposed by Einstein to show that he can violate the energy-time uncertainty relation, but, however, Bohr was able to defeat Einsteins argumentation by considering the uncertainty of the pointer in the weight measuring device. I want to point out, that a consistent description of measurments in quantum mechanics has to include the measuring device as a quantum system and thus the pointer has to obey the uncertainty relations of position and momentum as well (the generel measurement interactions were already described by von-Neumann in his famous book).

The argument from Bohr was like this:
The position and momentum of the pointer are denoted as $x$ and $p$ with its corresponding uncertainties $\Delta x $ and $\Delta p$. Once wehave choosen our degree of certainty in the pointer poisition the uncertainty in the pointer momentum is bounded from below by $\frac{\hbar}{2\Delta x}$. We now want to measure the weight of the emitted photon with the following procedure: after the photon is emitted, the pointer for th weight measurement points at a different position and by adding some new weight to the box we can bring the pointer back to its original position. But the accuracy of this weight measurement can notbe better then the smallest adde weight $g \Delta m$ and if we add the mass $\Delta m $ and wait a time $t$, the momentum delivered to the box can not be greater than $g \Delta m t$, and this mustbe greater than $\Delta p$ to have an observable effect. Thus we have $\Delta p < gt \Delta m$. Putting all together and using $\Delta E = c^2 \Delta m$, we have
$\frac{\hbar}{2} < \frac{gt \Delta x \Delta E}{c^2}$.
And now comes the funny part, which I personally like the most in the old Einstein-Bohr debates, namely that Bohr uses the theory of general relativity from Einstein to defeat him. Since a clock in the gravitational field ticks more slowly than a clock which is in free fall. And two clockes at different heights will run at different rates, because of their gravitational potential difference.If the difference in height is $\Delta x$, the fractional difference $\Delta t / t$ in their measured times will be $\Delta t / t = g \Delta x / c^2$. Thus over a measuring period $t$, the uncertainty in the time of the clock is $\Delta t = t g \Delta x / c^2$ and combining with the previous results we have
$\Delta t \Delta E \ge \frac{\hbar}{2}$,
your energy-time uncertainty relation.
I hope this is example is empirical enough despite beeing just a thought-experiment.
A formal understanding of the uncertainty relation between energy and time can be seen, like for position and momentum, from the Fourier Transformation between time and frequency domain (frequency and energy are essentially the same despite a proportionality factor). Since every wave-mechanics has the property of dispersion relations between the two spaces, and since the Schrödinger wave-mechanics is such a wave-theory we have this uncertainty, but which is not purely quantum mechanical since the same appears in classical wave mechanics.
Comment: While this explanation might have defeated Einstein, it seems rather odd that one should have to invoke general relativity to save Heisenberg time-energy uncertainty principle that is assumed to be true in non-relativistic QM. Is there a very precise understanding of what $\Delta E$ and $\Delta t$ means in this case?
Comment: Thank you for your comment, it is indeed a very surprising resolution of the 'paradox' posed by Einstein! From my point of view $\Delta E$ and $\Delta t$ can be understood in how precise you can determine the photons energy (by measuring its mass) during a time interval with accury $\Delta t$. I think, Einstein introduced this thought-experiment in order to decouple a measurement of time from a measurement of time by inferring the energy of the photon from a position measurement which has no uncertainty relation with time.


Flag category for immediate removal for typical "gimme da codez" type questions

Question: For the past couple of days I have been noticing an increment on questions that just ask for code. I think that it will beneficial for the community if there was a flag category (probably available to users with high reputation(10k+)) that will allow immediate removal of such questions. When the question is removed a message should be displayed to the original poster explaining that SO is not an avenue to get code.
Comment: My standard comment: *It looks like you want us to write some code for you. While many users are willing to produce code for a coder in distress, they usually only help when the poster has already tried to solve the problem on their own. A good way to demonstrate this effort is to include the code you've written so far, example input (if there is any), the expected output, and the output you actually get (console output, stack traces, compiler errors - whatever is applicable). The more detail you provide, the more answers you are likely to receive.*
Comment: I see *no need* to insta-nuke such questions. That is what closure is for. I am all for giving new users the benefit of the doubt too, give them a chance to improve their question.
Comment: That's what the 'minimal understanding' flag is for. I also leave a comment (using the AutoComments extension makes this easy) to explain that asking for code is usually not going to work.
Comment: By showing us what they have tried so far. If they haven't tried anything yet, the question will get put on hold.
Comment: The advantage is that I can *customize* the comment to tailor to the question at hand.
Comment: Maybe it is not a flag, but a button high rep users can click
Comment: but how will a user improve a question that just asks us to give them code?
Answer: But it is an avenue to get code. Almost all answers contain code. It's not an avenue to get a lot of code written from scratch. Questions that want that should qualify for being put on hold as not demonstrating minimal understanding, and shouldn't be insta-deleted, because it's possible that with prompting the user can learn what is expected of them, add some information, and end up with a useful question.
Comment: I agree that SO is an avenue to code after some effort is shown, but what I mean is just for answers that directly ask for code, like you can tell it is for some sort of homework problem or just someone being lazy. I really think that nobody really benefits for questions that flat out ask for code. These  get deleted after the voting process **if** they get enough closing votes; why wait? That is why I said the user should be prompted that SO is not an avenue to get code with no effort (we are not here to do your homework or your job for that matter).
Comment: some are deleted. Some are improved. Hang out in the reopen queue and you will see people trying to learn how things work here. I think that should be encouraged.
Answer: I suspect that asking a "gimme da codez" question is one of the first interactions most of these coders will have had with SO.  As such, responding with "go away.  We don't serve your kind here" is counterproductive.  We should be trying to teach these people the right way to use SO rather than drive them away.  Now, maybe you can put together an automatic message that says "fix this and try again - this is how" more than it says "welcome to the failboat, population you" but that's not what first springs to my mind as the likely experience from instadeletion with a canned message.  Even if you only manage to get 10% of the people who ask these questions to come around to the right way of doing things, it's a significant win, and worth some extra hassle winnowing them out from the rest who are hopeless.
Comment: I agree with the automatic message, but if we are still seeing people asking these type of questions it is because they are clearly not taking the time needed to even read the rules. Look at this comment for example http://stackoverflow.com/questions/20172595/android-login-screen/20172735#comment30072796_20172735
Comment: You're right.  They're not bothering to read the rules.  I'd suspect that people who bother to read the rules and pay attention to them also tend to write pretty good questions first time out.  This doesn't change the practical implications of various techniques with respect to trying to turn them into productive SO members, however.


What is the difference between "suffer for" and "suffer from"?

Question: I have a question about "I've suffered for my sins." why is used "suffered for", not "suffered from"?
Comment: They mean different things. Use whichever expresses your intent.
Comment: You might suffer *for (because of) your sins* or in paying your dues for sinning, but not from them. After all, let's admit that we sin because it produces pleasure, short term.
Comment: "I've suffered for my sins" is the way you generally want to say it, meaning "I've done bad things and my life is not good because of it". "I've suffered from my sins" is rare, it sounds like you're literally hurting like maybe you have liver disease from drinking too much.
Comment: It is the difference between "for" and "from."
Comment: The _reason_ that I suffered is what I "suffered for". The _cause_ of my suffering is what I "suffered from".
Answer: "Suffer for" introduces a reason for punishment or suffering that is typically caused by other human beings, and which people either choose to accept because of what they believe in, or are forced to endure because of their past actions (this is the sense in "suffer for my sins"). "Suffer from" is used to identify a disease or ailment, and doesn't have the same moral element.
Suffer for The OED has examples of this under meaning "3 a. To undergo or submit to pain, punishment, or death." Examples it gives include "Every Man is obliged to suffer for what is right, as to oppose what is Unjust." "It was a hard thing to suffer for an opinion; but there are times when opinions are as dangerous as acts." In this case the phrases "for what is right" and "for an opinion" are using the sense of "for" that expresses a goal or cause. Hence "for" introduces the reason or purpose for the suffering, and it is typically connected with punishment or suffering on account of human action.
Suffer from This expresses (OED 3 b) suffering due to "a disease or ailment", examples "She had suffered much from disease." "She was suffering from what she was pleased to call a fit of depression." Here the suffering is based on a physical cause.
See: "suffer, v." OED Online. March 2021. Oxford University Press. (accessed May 06, 2021).
Comment: Your explanation should say "suffer for...sins," not "suffer for." That's because "suffer for" isn't limited to the reason for the suffering since "for" has more meanings than "because," It can, for exmple, also mean "on behalf of," so if I "suffer for" you, then I'm suffering on your behalf, which doesn't also mean because of you because when it's my free choice to do so, it is because of me. That's just one example. Another would be "in sensitivity to," like if you're grieving and I say, "I suffer for you," I'm saying that I suffer in sensitivity to you in what you're going through.


Mention on tour page that this site is first and foremost about enterprise-grade stuff

Question: It's mentioned already on the [help/on-topic] page but it might be also worth adding to the tour page.
Answer: I think it's a good suggestion to show a short summary of the most important criteria for posts being on topic there. It may help stop some of the obviously off topic questions (educational, home networking, etc).
Answer: The Tour is really about an overview of how to use the site, and it actually says:

Looking for more in-depth information on the site? Visit the Help
  Center

The Help Center is the proper place for that sort of site specific information.
Comment: On many other SO pages the "Ask about..."/"Don't ask about..." section is more detailed than here. Have a look at e.g. http://superuser.com/tour.
Comment: @phk, the Super User Tour page to which you link doesn't seem any more detailed about what is, or is not, on-topic for that site than the Network Engineering Tour page does. Both the tours seem nearly identical. The last time the NE [What topics can I ask about here?](https://networkengineering.stackexchange.com/help/on-topic) page was updated, it was put here, on Meta, for a vote, and the community agreed to what is on there now.
Comment: Again, I'm specifically talking about the "Ask about..."/"Don't ask about..." section of the tour page. On https://networkengineering.stackexchange.com/tour you just have e.g. _"Ask about... Specific issues with network engineering"_ and _"Don't ask about... Anything not directly related to network engineering"_ while on https://superuser.com/tour you have _"Ask about... Specific issues with computer software, hardware or networking"_ and _"Don't ask about... Issues specific to corporate IT support and networks"_.
Answer: It happened in the meantime and it's quite detailed:

Ask about...

Specific issues with network engineering
Real problems or questions that you've encountered
Operating, maintaining, purchasing or managing an enterprise / service provider network
Planning or designing an enterprise / service provider network
Model or product line features and differences
Lab scenarios involving on-topic equipment
Tools used by network professionals
Servers operating as a router/switch/firewall
Design or theory of protocols used to operate a network (IP, TCP, routing protocols, STP, etc.)
Content delivery networks
Production troubleshooting or problem resolution
Physical infrastructure (standard color coding of cables, types of fiber, etc)
Implementing and enforcing network security or policies

Caveats:

Networks must be under your direct control (if the network is not under your control you will not likely be able to provide the
  information required to answer your question)
Hardware that has a paid support option from the manufacturer (enterprise/provider class products, some small business class
  devices) Not all questions work well in our format. Avoid questions
  that are primarily opinion-based, or that are likely to generate
  discussion rather than answers.

Don't ask about...

Anything not directly related to network engineering
Questions that are primarily opinion-based
Questions with too many possible answers or that would require an extremely long answer
Residential/home networking
Consumer grade products
Installation, configuration, or use of applications not generally considered to be tools used by network professionals
Configuration or operation of computers/servers not directly related to networking
Education, certification, or homework
A network under someone else's control
Product, service, or learning material recommendations
Configuring an application or device to work on the network
Protocols above L4 in the OSI model (e.g. HTTP, FTP, etc)
Bypassing network security or policies
Historical trivia that does not allow for a concise and non-subjective answer or is trivial/irrelevant to modern networking


Why is there a time limit/ waiting period before accepting an answer?

Question: Why is there a 15 minute waiting period before allowing users to accept an answer on Stack Exchange?
Answer: It started here:
Discourage questions being marked as answered within an hour or so of being posted
The rationale is that if people are accepting answers within minutes or even seconds (no joke), they haven't even had time to properly evaluate or test the answer.  The community felt (and I agreed) that some users were just accepting the first answer that was submitted even if it was wrong or sub-par.
15 minutes was decided on as the minimum amount of time it would take to receive a healthy number of submissions and actually read/test/think about the answers provided.
Comment: Thanks for providing a resource for further explanation.
Comment: Agreed, much better answer than mine -- I was feeling lazy :-)
Comment: Do you get a reminder or something if you have an open, answered question with unaccepted answer? I might be active for only 20 minutes and then forget I still have to accept that great answer I got 18 minutes ago.
Comment: @Rudie: There is a message that shows up, as mentioned in [this recent question](http://meta.stackexchange.com/q/87767/141911). I think the message goes away after several days/weeks and possibly disappears once you hit a certain reputation.
Comment: I'm very curious. Don't think I've seen it before. Now I'm gonna wait for it... Is that okay? =)
Comment: @Rudie so, did you end up seeing that message?
Comment: @ShadowTheKidWizard I don't think I've ever seen it still. Buuut I haven't asked a question for a while.
Answer: To allow people enough time to answer, and allow enough answers to come in for you to choose the correct one.
Comment: When was this put in place?  It has been a while since I asked a question on SO
Comment: As far as I know it's been there forever... but I don't know that much ;-)
Comment: Ah ha -- I *was* wrong. Thanks @Tradition!
Answer: It was implemented in the past two months.
People felt that in order to help get rid of the fastest gun in the west problem, delaying the time until a user could accept an answer would give everyone a fair chance at answering it to the best of their ability.


White cloud of foam while fermenting tepache

Question: I have lately tried to ferment tepache, for the firs time. The first stage went well, after three days there were white bubbles, it tasted less sugary and a bit yeasty. When I bottled it for the second fermentation, with no air flowing in, after 12 hours I came back to see this cloud of white foam. I am wondering what it might be.
Comment: Is there any reason to think that it's anything other than carbon dioxide + sugar?
Answer: Are you able to share a picture of what this foam looks like?
If you are sure that the bottling is tight and there is no air seeping in, then it is most likely just carbon dioxide that is rising up the surface and creating the bubbles. During second fermentation, carbon dioxide is still produced.
However, if there is a possibility of any air seeping in, then it could be kahm yeast. Nothing to worry about, you can just skim it off and the rest of your tepache will be fine.


Is it advisable to use multiple addressing schemes on the same lan?

Question: Is it advisable to use multiple private addressing schemes on the same lan to be able to tell them apart easily in tcpdump or similar? e.g., fw 10. dmz 172.16.  wifi 192.168.  Will this cause headaches for me later? What are the unforseen potential problems?
Answer: It will not create any problems at all – addresses are just addresses, and IP doesn't care whether they're public or private, nor whether they're from the same base range or different ones.
What it'll create is inconveniences as it makes route aggregation harder or impossible. For example, if all my subnets are 10.147.x.0/24, then I can say "allow 10.147.0.0/16" in a firewall rule and that'll match them all in a single rule. But you will need to list different parts of the LAN individually – at minimum you will need three separate entries (one for each private range).
Routing also becomes more complex if you use static routes. Let's say you have a main router, and then a secondary router that has 5 subnets for whatever reason. If they share the same base prefix, the main router only needs to know one aggregate "supernet" route via the secondary router. If they don't, it needs five.
Very similarly, if you wanted to configure a VPN server for reaching your home systems on the go, you would usually tell it to advertise specific network routes to connecting clients. If all your subnets share the same prefix, you only need to configure the VPN server to provide that one prefix – but if they don't, then you have to list every one of your subnetworks.

This is actually related to how subnetting was invented. At first, IP networks only had 3 sizes ('subnets' and 'netmasks' did not exist), but organizations soon found it very inconvenient that they needed to request multiple /24's (then known as "class C's") to represent different parts of their large network. When subnetting was introduced, they became able to request just a single /16 range (a "class B") and subdivide it internally.
Comment: Very thoughtful and detailed answer, thank you. This is my proposed network rollout https://postimg.cc/qzy774xB as you can see I have five network segments, with five gateways. You are saying each one will have a different representation of the network in the routing table and that will be/become a PITA to maintain and aggregate to all the hosts. A nightmare in short. I will revise my network map using a 10. scheme. Thank you.
Answer: What you are doing will work, but honestly, you're making your address scheme way too complicated.
Just use the 10.x.x.x network and cut it up into class-C segments.  Something like:
fw  - 10.1.1.x/24
vpn - 10.2.2.x/24
dmz - 10.3.3.x/24
lan - 10.4.4.x/24
wifi -10.5.5.x/24
That would give you 256 addresses per subnet to tinker with and using easy 10.1-2-3-4-5 numbering will make it easy to remember at a glance where you are.


Is there an easy way to make all pages of a DNN site viewable by registered users only?

Question: I have a DNN site that I now want to change so that users must log in beofre they can view any of the content.  I can go to each page an change the permissions but i am looking for a faster way  - even if that means going into the database.
Answer: This will remove all of the "Unauthorized Users" permissions from all of the pages on a portal:
DELETE
FROM TabPermission
WHERE RoleID = -3 -- Unauthorized Users
AND TabID IN (
    SELECT TabID
    FROM Tabs
    WHERE PortalID = YOUR_PORTALID_HERE
)

Then replace all of the "All Users" permissions with "Registered Users":
UPDATE TabPermission
SET RoleID = -2 -- Registered Users
WHERE RoleID = -1 -- All Users
AND TabID IN (
    SELECT TabID
    FROM Tabs
    WHERE PortalID = YOUR_PORTALID_HERE
)

After you run this, go to Host -> Host Settings and under the Performance section hit "Clear Cache".
You could run a similar statement against the ModulePermission table but it shouldn't be necessary if you're locking down all of your pages since if they can't view any pages they won't be able to view any modules.
Not responsible if any of this destroys your database, injures your pets, etc. Make sure to backup your database before running the script!
Answer: The fastest, non-technical method is to go to the parent pages on the portal, change the permissions to suit you, then copy those permissions to the child pages.  If you have tons of parent pages, go to Admin>Pages and group all parent pages under one parent page... change the parent permissions and copy to all child pages, then reinstate your page hierarchy.
Answer: The fastest way would be to write an update statement against the TabPermission table.  Most likely you would change all of the -2 or -1 (depending on DNN version) values to something like Registered Users.
Use caution, backup your database, and test it before you actually do it in production.  I can't stress that enough.
You'll want to look at the ModulePermissions table as well.
Answer: You can just use IIS authorisation to do it, if you wish, but it doesn't provide "registration".
http://msdn.microsoft.com/en-us/library/aa292114%28VS.71%29.aspx
Comment: DotNetNuke has its own registration and permission system.
Comment: Lance: Yes, obviously, but you'll note that's not what he asked.


Best armor type for warrior build?

Question: I am a level 11 warrior build in Skyrim and I was wondering what armor type I should use... I started out using light armor because I have a shield and I didn't want to be weighed down by heavy armor, but now I know that you can eventually make each armor weigh 0. I was thinking that maybe I should start using heavy armor now and that it would be a better choice in the long run. my light armor is 15 levels higher than my heavy armor now, but I only spent one point in it.
Comment: The benefit of light armor is having less useless perks.
Comment: @kotekzot If you read my post over at http://gaming.stackexchange.com/a/48548/8581 you will actually see I advocate taking No armor perks :)
Comment: @James not all armor perks boost armor rating, you know.
Comment: Yeah but I have not needed any more armor rating, or reflected damage, or faster stamina regen and the like.. So I still see no point into putting perks into other areas just for those abilities.. To each their own and all.. I am just pointing out those perks are just not that great compared to others.
Answer: It honestly does not matter. It has been proven many times that any type of armor can actually max out the armor caps with just 1 or 2 perks in their respective armor trees depending on which armor you want to use (maxing out leather or iron takes a bit more perks/enchants than say daedric or dragon).
They really do give you the ability to play any way you want and to remain viable. The link above shows the minimum perks needed to max out each classification of armor so you can pick what you want to look like and aim for that end goal.
Comment: the 'many times' link is dead.  But, I think, this is the same thing?  http://www.gamesas.com/complete-character-design-freedom-damage-resist-caps-and-t232634.html
Answer: if you want to have little damage then just use heavy armor and the steed stone: fortify carry weight and your armor weighs nothing so like that you can use and train heavy armor without being slowed down.
or just level up more stamina and use a 2 health to 2 stamina ratio.
it also depends if what weapons you use because two-handed does more damage but slows you down because of its weight.
Answer: Actually, the best armor with BASE armor dating is a full set of deathbrand armor, though it's light armor and you need DB dlc, not to mention you have to be level 36 to get the armor
Answer: All up if your beginner I would suggest Dwarven
Levels 12-16 Go Orcish
Levels 16-20 Should probably go for Bone/Ebony Or Daedric if you don't have any of these stick with orcish until you can smith Bone/Ebony Or Daedric!
Answer: If you have any 3 DLCS And are able to smith nordic that's a good one for begginers
DO NOT GO BONEMOLD
Answer: I would use any kind; if you are leveled high enough as a werewolf, it won't matter.
Answer: If you choose heavy, I suggest using wolf armor. The helmet helps but what I really use is an enchanted hood, which keeps you from losing too much stamina while attacking.
The wolf armor is the best heavy armor you'll find — especially if you are a werewolf.
Comment: I seriously doubt the steel-grade wolf armor is better than daedric.

Best armor type for warrior build?


Where can I find samples of position papers?

Question: I have been invited to contribute a position paper to an upcoming conference on higher education. However, I am unfamiliar with them beyond a general description.
I'm concerned about what the norms are for these kinds of papers (since I have never written, nor read, one). Some questions I have include:

How much evidence for the position is normally provided?
What kinds of questions are reasonable to leave unanswered?
How long are they?
What level of counter-argument should be included?

I believe after reading a few I could answer these, which is why I'm asking this question.
As I look for samples, 90% of what I find relate to Model UN. Is there a good source to find samples of position papers for academic conferences?
Answer: How much evidence for the position is normally provided?
As much as possible, actually. In a position paper, you might want to develop an hypothesis that matches previously made findings. Or you might argue that past empirical research has got its results wrong in some way because of an unaccounted for measurement or protocol error. Or you might want to make a theoretical argument, or take multiple findings from existing papers and try to explain a connection between them. If you have an hypothesis which sounds plausible (as in consistent with correctly-made empirical observations and with at least one family of theories) and you find that you need some additional research before you can confirm or reject it, a position paper is a great way to expose it.
What kinds of questions are reasonable to leave unanswered?
The ones that need a costly / difficult proof. You want to expose an opinion or idea so you get feedback on it or potential collaborators.
How long are they?
It depends on your field. In computer science, they're usually short papers in conferences or full papers in workshops.
What level of counter-argument should be included?
I'm not sure I get this question. If you know about evidence that contradicts your hypothesis, include it, and explain why you think the evidence can be neglected.
Where to look for position papers?
Go to your favourite academic search engine and make a search on papers that contain "position paper" in their title. Also, look up all recent workshops in your specific field (those you'd submit your position paper to).


Electronic Sparking/Arcing Sounds

Question: Has anyone got any tips on creating/recording electronic spark/arcing sounds? Is there anyway to create these without an arc welder or a tesla coil?
Comment: Have you got max/msp?
Comment: I don't have it at the moment but I have had a bit of experience using it. What would you recomend?
Answer: There was a thread on Twitter about this last year - challenging, eh? While ideas thrown around included miking fluorescents, buzzes, hums, and even the sound of packing tape for short static-y bursts, the best idea I came across was this brilliant guest contribution on Chuck's blog. Bug zappers, who knew?
Comment: Cheers, that looks like the way to go.
Comment: **UPDATE** If you're willing to wait, Chuck might have you covered...via Twitter: "I will be doing an electricity sound library. ETA unknown. lots of planning to do." 8/13/2010
Answer: Fireworks -- Specifically sparklers.  Every year, my friends and I get together for the 4th of July, and one of our favorite things to do is to bundle as many of those cheap metal sparklers together as we can (200 is our current record) and light them all off at once  The sound is awesome, but don't look directly at it.
Answer: I've had some good results in the past by close miking incandescent bulbs with highly directional mics. The buzz and hum they give off are a good starting point. Just watch out you don't burn your mic. lol

Electronic Sparking/Arcing Sounds


Response time and time constant of Mercury thermometer

Question: I searched to find differences between response time and time constant of a thermometer. So I found that those two are not same and we have to get 99.3% of the total step change to find response time and we have to get 63.2% of its total step change to find time constant of thermometer... Is this correct or not and are those percentages are correct or not? Can you explain why that is...
Thanks in advance...
Comment: So a mercury thermometer?
Comment: Yes it is a mercury thermometer.
Answer: Response time, more precisely called settling time is time after the system output settles to the new value after change in the input (in your case the output is reading of the thermometer and input is actual value) - more precisely time after the error between target value and actual doesn't exceed certain threshold, because the value will never reach that targen in finite time, it will only asymptoticly approaching it. How big is that threshold (how wide is error band), depends on arbitrary decision - in your case it seems like it's 0.7% error, which is quite small one. More often it's something like 2 or 5%. But to settling time be meaningful that error band need to be known.
Time constant on the other hand is just constant in equations/transfer function describing the system. For first-order system (which thermometer probably can be approximated with) it just happens to be equal time after 63.2% of that change is made. That's because for first-order system it describes time after output would reach target level if initial rate of change was maintained (see initial rate of movement on the picture below). And since the value changes are exponential it turns out to be 63.2%.

(First order system step response)
If you want more information about the subject I suggest reading more about control theory. Keep in mind though that it's a bit math-heavy subject.
Comment: Thank for your answer that was really helpful for me.
Answer: I'd guess specifying the response in a different way.
The typical first order unit step response is an exponential decay, $1-e^{-t/T}$ where $T$ is the time constant. The value of the expression after $t=T$ is $1-e^{-1}$ or 0.632=63.2%. That's where that comes from.
The 99.3% is either writing the same specification as another multiple of T (i.e. $t=5T$, thus $1-e^{-5}$ = 0.993 =99.3%), and/or that the system is not first order, which shouldn't be assumed.
Possibly they're picking a response time to a ~1% error, because that may be a safer or more useful figure for users.
The response of an old school glass thermometer will be a (mostly) axial-symmetry heat transfer problem, FWIW.
Comment: This answer was very helpful for me. Thank you so much for your answer


What do neural networks offer that traditional non-linear statistical models do not offer?

Question: I have tried to find an answer to this question but have not found a satisfactory answer. I understand that neural networks(NNs) offer the potential to complex build non-linear models. What I don't understand is what do NNs offer that traditional statistical non-linear models do not offer. In other words, why would I choose a NN model over a statistical model (e.g. non-linear regression) at least in some cases?
Comment: [Keep in mind that the traditional statistical non-linear models are, in a sense, ANNs as well](https://stats.stackexchange.com/questions/362425/what-is-an-artificial-neural-network).
Answer: The ability to embed structural and algorithmic priors into the model.
The simplest example of this is convolutional neural networks applied to image data. The structural prior is that nearby regions of the image are more closely related / relevant to each other compared to far-away regions.
Graph convolutional networks extends this "locality" prior to arbitrary graph/network structures. 1D and 3D convolutional networks extends this prior to sound / 1D signal data and 3D scans respectively.
Powerful quadratic programming solvers have been developed. It is possible to literally embed such a QP solver as part of a neural network, inducing an algorithmic prior which says "find solutions which make use of QP". Value Iteration Networks forces a prior which says "make use of this well known RL algorithm to solve this RL problem".
Computer vision scientists can build 3D geometry into a neural network, enforcing the prior "we live in 3D euclidean space, and here is our camera model" into the architecture of the network.
Comment: (-1) This is definitely not something unique to NN, in fact it is found in just about *all* statistical models. Furthermore, I would actually argue this something NN are worse at, in that interpretation of the parameters for NN is notoriously difficult compared with many other classical statistical models.
Comment: @CliffAB could you provide some references or examples of how one might augment a random forest (or a non-linear model of your choice) with domain knowledge of perspective camera geometry or take advantage of the spatial relationship between voxels in a 3D scan?
Comment: the field of spatial statistics uses domain knowledge of spatial relations to more efficiently build models from spatial data.
Comment: But more generally, if you want to talk about a framework for simple inclusion of domain knowledge information, it's really hard to argue that this is what Bayesian statistics does. There's nothing that says you can't have a Bayesian NN, or think of a penalized NN as an approximation of a Bayesian inference, but to say that the strength of NN is the ability to include prior information is a very strange statement to me.
Comment: I don't mean any prior on the parameters, which almost all models can make use of. Rather, I mean structural and algorithmic priors which can be built into the architecture of the network, but would otherwise be difficult to impose via a prior on parameters.
Comment: sure. But basically any model that's intended for a specific type of data does that, i.e., spatial models for spatial data. And I'm not saying you can't build these things into NN's; I've been to a few talks where they talk about very clever ways of doing so. But to say this is a unique strength of NN's doesn't make much sense to me.
Answer: It's my understanding that at this point in time, there is no real solid mathematical reason for why NN have seen as much success as they have. Perhaps that's why you can't find any thing convincing at this time, although there are plenty of heuristic arguments.
The one proof that this brought up a lot (for good reason) is the "Universal Approximation Theorem"; that is, with enough neurons, any smooth function can be approximated arbitrarily well by a large enough neural network. This suggests that given enough parameters in our NN and enough data, we should be able to get arbitrarily close to the true function we are attempting to approximate.
However, the Universal Approximation Theorem alone doesn't explain the success of NN's, as NN are definitely not the only type of machine learning/statistical model that have this type of property! For a very simple alternative, you could take a linear model and simply expand the covariates to include non-linear terms and interaction effects. This can also approximate any function given enough expansions.
Now in the case of linear models, although the Universal Approximation Theorem is true, we can do the math right away to see this becomes much too data hungry to ever be of practical use. For example, suppose we have a model with $k$ covariates. A simple linear model with no parameter expansions requires fitting $k$ coefficients. If we want to include just the first order interaction effects, we are now up to $k^2$ coefficients. While this is a richer set of models than simple linear effects, it's still not that complicated. If we want to include third order effects, this requires $k^3$ coefficients. Note that we haven't even addressed adding non-linear parameter expansions yet. If $k$ is at all large, it becomes obvious that this is not going to work out well for approximating functions in which the covariates have complex interactions.
So to me, the real question is which kind of models can approximate complex relations from a finite set of data well. I think the paragraph above is fairly convincing that linear models with simple parameter expansions are not the way to go. It's my understanding that the argument for NN's is that (a) there's no convincing argument that they won't work and (b) empirically, they seem to be working quite well in a wide body of problems when one has lots of data and complex interaction of features.
Comment: I think you are missing the point that the main area of benefit has been in image processing.. specifically for convolutional nns.(they haven't been universally successful, and for this application it's hard to think how alternative models could fit the requirements of fitting inside convolution.
Comment: @seanv507: while NN, and most recently CNN's specifically, have had lots of success in image processing, my understanding is that the question is about why they've had success in so many other fields (language processing, reinforcement learning, etc., just to name a few). I think what you're getting at is that convolutions fit nicely into the NN framework, as they are simply a constrained rather than fully connected layer? But note that they can also be seen as a moving average, which is used quite often in many models (although perhaps with not as much freedom to optimize the weights)


Need help in adding new lookup column in SharePoint List

Question: I have a list for Person in which there is a lookup column for StateID of States list. In States list there is a lookup column for CountryID of Countries. I want to add CountryID to Person list by using existing StateID lookup column, but when I edit StateID column from List settings of Persons list I didn't see choice for selecting CountryID lookup column to add in Persons list.
Please help, please let know if this is the correct way to do this or if it is not possible.
Answer: States list must be have CountryID, then you can add that to Persons list.
you can add CountryID as calculated id to States list and then you can see that when you want to create StateID lookup column.
Comment: When I am trying to add new Calculated column, I didn't see StateID in available columns list, maybe I didn't get what you meant to say
Comment: when you want to add CountryID lookup column to the States List CountryID under "Add a column to show each of these additional fields:" you cant choose ID and you have column with tile Country:ID and name Country_x003a_ID
Comment: Thanks for reply, I added new column to States list for Country:ID as suggested by you, but it still doesn't appear in Persons StateID Lookup column for adding other columns from States list


What is the difference between reinforcement learning and deep RL?

Question: What is the difference between deep reinforcement learning and reinforcement learning? I basically know what reinforcement learning is about, but what does the concrete term deep stand for in this context?
Answer: Reinforcement Learning
In reinforcement learning, an agent tries to come up with the best action given a state.
For example, in the video game Pac-Man, the state space would be the 2D game world you are in, the surrounding items (pac-dots, enemies, walls, etc), and actions would be moving through that 2D space (going up/down/left/right).
So, given the state of the game world, the agent needs to pick the best action to maximise rewards. Through reinforcement learning's trial and error, it accumulates "knowledge" through these (state, action) pairs, as in, it can tell if there would be positive or negative reward given a (state, action) pair. Let's call this value Q(state, action).
A rudimentary way to store this knowledge would be a table like below
state | action | Q(state, action)
---------------------------------
  ... |   ...  |   ...

The (state, action) space can be very big
However, when the game gets complicated, the knowledge space can become huge and it no longer becomes feasible to store all (state, action) pairs. If you think about it in raw terms, even a slightly different state is still a distinct state (e.g. different position of the enemy coming through the same corridor). You could use something that can generalize the knowledge instead of storing and looking up every little distinct state.
So, what you can do is create a neural network, that e.g. predicts the reward for an input (state, action) (or pick the best action given a state, however you like to look at it)
Approximating the Q value with a Neural Network
So, what you effectively have is a NN that predicts the Q value, based on the input (state, action). This is way more tractable than storing every possible value like we did in the table above.
Q = neural_network.predict(state, action)

Deep Reinforcement Learning
Deep Neural Networks
To be able to do that for complicated games, the NN may need to be "deep", meaning a few hidden layers may not suffice to capture all the intricate details of that knowledge, hence the use of deep NNs (lots of hidden layers).
The extra hidden layers allows the network to internally come up with features that can help it learn and generalize complex problems that may have been impossible on a shallow network.
Closing words
In short, the deep neural network allows reinforcement learning to be applied to larger problems. You can use any function approximator instead of an NN to approximate Q, and if you do choose NNs, it doesn't absolutely have to be a deep one. It's just researchers have had great success using them recently.
Comment: "Deep" would be from [Deep Learning](https://en.wikipedia.org/wiki/Deep_learning) (emphasis on the multiple processing layers). To generalize, we could argue that the Deep RL label could be applied to any RL scheme that has a deep learning component to it. E.g. [this paper](https://www.aaai.org/ocs/index.php/WS/AAAIW11/paper/viewFile/3898/4303) uses [_Deep Belief Networks_](https://en.wikipedia.org/wiki/Deep_belief_network) as the approximator. Before [you ask](http://stats.stackexchange.com/questions/51273/what-is-the-difference-between-a-neural-network-and-a-deep-belief-network) :)
Comment: Other papers: [Deep Auto-Encoder Neural Networks in Reinforcement Learning](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.172.1873&rep=rep1&type=pdf), and perhaps the most known one [Playing Atari with Deep Reinforcement Learning](https://www.cs.toronto.edu/~vmnih/docs/dqn.pdf), uses a deep (and convolutional) Neural Network.
Comment: Thank you very much for your comprehensive answer. So as I understand the **deep** refers to the approximation of Q through a neural network and the associated possibility of using reinforcement learning in a larger scale.
Answer: Summary: Deep RL uses a Deep Neural Network to approximate Q(s,a).
Non-Deep RL defines Q(s,a) using a tabular function.

Popular Reinforcement Learning algorithms use functions Q(s,a) or V(s) to estimate the Return (sum of discounted rewards). The function can be defined by a tabular mapping of discrete inputs and outputs. However, this is limiting for continuous states or an infinite/large number of states. A more generalized approach is necessary for large number of states.
Function approximation is used for a large state space. A popular function approximation method is Neural Networks. You can make a Deep Neural Network by adding many hidden layers.
Thus, Deep Reinforcement Learning uses Function Approximation, as opposed to tabular functions. Specifically DRL uses Deep Neural Networks to approximate Q or V (or even A).
Comment: You can do function approximation to the policy function or to the value function. Or both. Policy approximation, in this case, is achieved by Deep Neural Networks.
Comment: oh, not just the DNN for policy, also the DNN to be used in place of Q-function?


Problem with Mass Registration

Question: There is no option to "Add Contacts To Event" once multiple contacts are selected from a specific event. How do I make this option available?
Comment: hi courtney - it would be really helpful if you acknowledged and/or accepted answers provided by volunteers
Answer: Create a temporary group, add the selected contacts first to a group and after that go to search, select the contacts in temporary group and add the contacts to the event
Comment: I think you meant 'temporary' and have edited your answer accordingly.  I hope that's okay.
Answer: I just had the same issue.  Look for "Register participants for event" instead.

Problem with Mass Registration


Basic setup for InfoPath 2010 Person/Group picker

Question: After configuring a Person/Group picker in InfoPath 2010 I couldn't get the "Filler" version of the form (client enabled, not web enabled) to successfully pull names from Active Directory. I thought that I had set everything up correctly, and I mostly had. In my answer I'm going to give a quick play-by-play for setting up a Person/Group picker.
Comment: So I think you need to add the next step of connecting the Context.xml file to the people picker field properties in infopath form, right? I feel like there is a step missing here, because following the example does not make the people picker functional. Nothing currently happens when I click the directory button or the check name button.
Comment: I don't know what to tell you; I just followed my exact steps to a T and it works as described. Check that you've changed the `siteUrl` in the Context.XML file to your domain name. Also check that your data connection is set to receive an XML document *and* that it is in a universally accesible location. Perhaps my development environment is different enough from yours that I don't encounter the same obstacle you're seeing! Good luck!
Answer: First things first. Create an InfoPath form, put a Person/Group picker on it.

Create the "Context.XML" file - described here
Use Notepad or any text editor
Enter in the following snippet: <Context siteUrl="http://mydomain.com"/>
Change the domain name to your own domain
Save the file as "Context.xml" and upload it to a universally accessible location on your SharePoint site
It is important that it be placed in a location where all form users have at least "Read" access

Now we set up the data connection in MS InfoPath

Create a data connection called "Context"
Set the data connection to "Receive"
Set your data source as an XML document
Enter the URL of the uploaded XML document on your SharePoint site as the location of the XML file
I personally chose "Include the data as a resource file in the form template or template part"
Name the connection "Context"
I personally left the "Automatically retrieve data when form is opened" checkbox selected.
Now publish the form!

At this point my form was successfully able to access the AD listing. Prior to that I had gotten a "Server did not respond" error (or something along those lines).
I hope this proves to be helpful!


How do I remove the "My account" and "Logout" links?

Question: I am trying to sub-theme the Bootstrap theme. How do I  remove the My account and Logout links from the navigation bar?
Answer: Try going to Appearance settings on your sub-theme admin/appearance/settings/... and uncheck Secondary menu.
If that doesn't work, check menu settings at admin/structure/menu/settings and make sure you haven't defaulted the main menu to "User menu".
Answer: Go to: admin/structure/block
find user menu and set 'none', as region.
Comment: There is no blocks in navigation zone but I (as logged in user) still see the link. I guess the links are not a block but hardcoded somewhere.
Answer: Simply, navigate to the user menu (admin/structure/menu/manage/user-menu) and deselect "enabled" for each item.


3 related problems - gap in content wrapper/border, image height reduced and positioning of content div

Question: The problems can be seen here:  http://www.skicoloradorentals.com/secondary.html
1) the gap below the contentBorderImg
2) contentBorderImg reduces to 69 pixel height instead of 87 (18 px diff = same as gap)
3) the content div doesn't sit over the contentBorderImg even though I assigned a high z-index to it
contentBorder - this is the wrapper/border for the content area with a 1-px border
contentBorderImg - this is the rounded corner image which is displayed over the top part of the wrapper
.content - actual content div that I want to reside over the contentBorderImg
I was able to make the same concept work in the left column.  I tried duplicating that code to no avail.  I appreciate your help immensely.
Answer: Try giving contentBorderImg's
Z-index = -1;

and then for #contentBorder use
border-radius:9px 9px 0px 0px;

I have used border-radius to mold the border as per the rounded corner image.


Acquiring first office clothes

Question: I'm currently a student who will be starting out in a position where business attire is almost a given. The thing is that saving up for suits, a change of shirts and dress shoes seems very hard on the thin margin I'm living at right now. Do you have any tips beyond buying everything second hand, because I'm afraid it'll show and cost me interviews? My time frame is at least six months.
Comment: This question might get a better response at [The Workplace](http://workplace.stackexchange.com/).
Comment: In what country do you reside, if the US what state?
Comment: @PeteBelford I live in Sweden, hope that paints a clearer picture.
Comment: For me, not at all.  Here in the US we have some great discount stores where one can shop for a fraction of the cost of a major retailers.  I am sorry but I have no perspective on shopping in any part of Europe as I have never been there.
Answer: While in the interview stage you need one good outfit. Take care of them and they will see you through this stage of the process. Shoes, ties, shirt, and a suit can all be purchased on sale. The fact that you have months before graduation give you time to purchase them when there is a sale.
Off-the-rack is good enough for a suit for this stage of your life. There is no need to go custom made when you are just starting out. In fact you may find you never need more than one or two suits, and they never need to be custom made.
Comment: Also, during the interview, or as soon as you start work , ask what the real requirements are. A good quality pair of chinos, a decent button down shirt,  respectable shoes, and maybe a sports coat or blazer will be formal enough for most jobs these days.
Comment: Also, keep in mind that at a lot of places like Joseph A Bank they will claim there is a sale 52 weeks of the year. Be weary of this.
Answer: Like the other answers, I'm not entirely sure the equivalent exists in your country. But in the US there are thrift stores run by charities like GoodWill or the Salvation Army that sell clothes for very little money.
When my wife was in a similar situation very early in her career she learned the trick of driving to thrift stores nearest to the richest neighborhoods in town. She often found high dollar designer clothes that had been worn once (to an event or party) and then donated. Apparently it is quite gauche for the well-to-do to be caught dead in the same outfit twice. It wasn't uncommon for her to find clothes/shoes that retailed for hundreds of dollars for $10 or so.
Answer: Sounds like you're a man, so you're in luck. Our formalwear all looks similar enough that you can get by on a very short rotation. You can buy 1 pair of decent slacks in a versatile color like navy or grey with a pair of brown shoes with matching belt then have as little as 2 button down shirts (white and light blue). You can help keep the button downs clean by wearing an undershirt.
This outfit can even overlap your interview outfit if you want to save more (especially if you want a good jacket/sport coat). The real key is to just not pick anything flashy and nobody will ever notice. You'll be running to the dry cleaners every single weekend, but you won't have much in terms of up-front costs.
For women though I have no clue how they manage this stuff.

Acquiring first office clothes


Is it best to move a poorly-performing website to a new domain name upon a major update?

Question: My rationale is since my site was poorly received, it will be better to get a clean state. There are many instances of bad user experience with the current site, related to slow loading and unresponsiveness. A new update is on the way that basically fixes all those concerns.
The site is almost a year old and has less than 200 visits. The new version is way more performant so should I stick with the old domain name or get a new one for the update?
Answer: I think that the content has more to do with this than the domain name.
Quote from John Mueller -

Finally, in 2020, Google Webmaster Trends Analyst John Mueller revealed keywords in domain names no longer play a role in determining search engine results rankings.
Answering a question if keywords in domain names impact rankings during an Ask Google Webmasters video, he said, "In short, no. You don't get a special bonus like that from having a keyword in your top-level domain."

From Is Domain Name A Google Ranking Factor?
Here's another

Does domain name affect Google search?
The domain extension, commonly referred to as the Top-Level Domain (TLD), generally isn't considered a Google ranking factor, except in the area of International SEO. In this case, having a specific country code top-level domains (ccTLDs) can indicate to search engines which country your content is targeted at.

From Does domain name affect Google search?
Comment: A new website (domain name) will take a while to get ranked.  First Google will have to trust your site.  Your old site is already trusted.  Even if it's slow and buggy.  Google will rescan and act according to the new content.
Comment: The old website was very buggy and slow i fear that when I roolout the update it may still have a poor ranking is it a reasonable concern?