Time series modelling

Question: I have daily data for 2.5 years , but with more data points as 0, so when i excluded them in the cases which seems to be invalid. Can i use any other model than models used in time series or should i consider time series with missing values and proceed ?
since they are quite a lot of missing values and am new to time series i dont know how to proceed with this. Any input is highly appreciated.
Comment: Please explain a bit more. What kind of daily data? You have many points that are 0 and you exclude them? Why do you think they are invalid?
Comment: I have data regarding 200 departments , and their production time , alloted time and time which is not productive.
but for few days daily data has not been recorded for some days there is no production. if i remove non productive days and non recorded days which are quite a lot, my prediction is not so good, if i clean them by replacing with mean or previous values,i still cant get better results. i want to know if there is better way to deal
Answer: First idea is to use, instead of an invalid data point, the last valid value. This is done in finance where some stocks are not quoted everyday (and when you want to publish the value of your fund you use the last available value for the stocks).
However, this can be an issue when you have too many missing values (especially for prediction).
You can try Bayesian data augmentation (works somewhat well with time series) but if you say that you have a lot of missing data you have to accept that anything that you do on rather poor quality data will be of limited quality.
Comment: I tried to add missing values with valid values, for prediction i have used auto arima and neural network for time series which gives me not very good prediction
Answer: IMHO the existing answer is essentially correct, but perhaps it can be phrased more explicitly or clearly.
You have the option of trying to fill in the gaps before you run a time series model. Depending on how well you can predict the missing values, and how many there are, this can give a better result that trying to predict from the data with the missing values directly.
To fill in a gap, you can use the last known value. This is known as the "naive forecast". Similarly, you may want to interpolate the gap (essentially connect the points before and after the gap with a straight line). Or you may have more knowledge about your data that allows you to do a better forecast than this, or perhaps, knowing your data, you know that neither of these suggestions is any good.
For example, I don't know if it makes sense that if the production of a department on one day was at a certain level, that the production is probably similar the next day. Could be. Or not. I don't know the business.
After filling the gaps (or after choosing not to fill in any gaps), you will have to run a time series model. An ARIMA model would work. A standard recurrent neural net (like GRU or LSTM) would have trouble with gaps I think, but perhaps you know some tricks to avoid that.
I would also echo the last statement of the previous answer: If your data is bad, then you cannot expect to get great results, so perhaps you shouldn't be too surprised. There is also the question of whether the historical data fully explains the variations. For example, perhaps they're downsizing or upsizing some departments, and you wouldn't be able to predict that from the historical data.
Comment: Thank you for the explanation, Arima didn't work well with my data, but i have tried arima only on few departments , which i could identify seasonality but when i have 200 departments is there any quick way to identify seasonality. Neural network did a good job for certain departments
Comment: You could use Prophet from Facebook. It's super easy to use and it gives you weekly and seasonal patterns.

Time series modelling


Can Metta improve one's luck?

Question: Since one can benefit so much from practicing Metta, can it also helps improving one's luck?
Answer: Yes. For 2 reasons I can think of:

Creates good Karma on which some can give results in this life time
Makes you pleasant and likeable hence increasing chances of some one dealing with you and supporting you
Answer: Luck is preparation meeting opportunity.
As discussed in this answer, Metta makes one dearer to others, strengthens one's mental concentration, brings peace to one's mind, grants protection by the Devas (gods or angels) and provides protection from harm (e.g. fire, poison sword).
So, if you can have a better relationship with others, then this improves your social networks. If you have better mental concentration, then you can correctly identify opportunities that appear before you. If you have protection from harm, you may be led away from unfavourable situations.
Metta therefore, forms part of the right preparation that will allow you to seize the opportunities that come your way.
However, we should bear in mind that worldly luck is not permanent (anicca) and is part of the suffering (dukkha).
Comment: Thanks for ur response. How is it part of suffering? I'm not quite following.
Comment: Joy and sorrow, pleasure and pain, good luck and bad luck, gaining and losing loved ones, good health and wealth, life and death - all of these are not permanent. There will be ups and downs. And these go on forever. That's suffering.
Answer: Sure... It might even expand your perception of "luck" so you can recognize the positive events that are always present but go ignored because we are the universe loving kindnessly bounded to ecah other through unconditional conditions...

Can Metta improve one's luck?


1001 Nights - Movie faithful to the outer story?

Question: I have heard of the story of 1001 Nights, and I know there have been tons of films made based on the stories in it.  However, I am having difficulty finding a film that actually uses as a framework the fact that the king takes a bride every day and then slays her, then Sheherazade comes and wins his heart with her stories.  Are there any films with this framework, and if so, would you mind listing it/them for me?  Thank you.
Comment: Most films about the 1001 Nights are made for children, and I doubt anyone would want their child to hear stories about how this great king killed his wife everyday.
Comment: Not a film, but Nikolai Rimski-Korsakov's symphonic suite _[Scheherazade](https://en.wikipedia.org/wiki/Scheherazade_(Rimsky-Korsakov))_ does exactly this.
Answer: In 2000, Hallmark Entertainent created a 2-episode-long miniseries entitled Arabian Nights, which aired on BBC One in the UK and on ABC in the USA. Strictly speaking, this is not a movie, but each episode being roughly the conventional run-time of a movie (1.5 hours), the complete miniseries could be seen as a double full-length feature. Among the cast are Dougray Scott (who I remember most as the villain in Mission: Impossible 2; here he plays the Sultan of Baghdad), Jim Carter (who currently seems to be best known from Downton Abbey), John Leguizamo and Andy Serkis. Jason Scott Lee plays Aladdin, who is portrayed here, like he is in the original story, as Chinese.
The series consists of five stories, the most famous among them being "Aladdin and the Magic Lamp" and "Ali Baba and the Forty Thieves." The overarching premise of the story is indeed based on the framework that the Sultan's new bride Scheherezade tells him a story every night, stopping at dawn with a cliffhanger, and then refusing to continue until dusk, and in this way she is able to save herself from execution. There are a few other palace intrigues which seem to be invented for the TV series but for the most part the overarching theme is quite closely based upon the source material.
See the series trailer here.


Is there an easy way to reduce quality of .mov files taken from an iPhone?

Question: I've noticed the small movies I take on my iPhone 4 result in large .mov files. For example, a 1 minute movie results in almost a 100MB .mov file. This is running through my cloud storage (Dropbox) rather quickly. Is there an easy way to reduce the quality/size after transferring to my Mac?
Answer: Most of this is documented:

How do you convert video within 10.7 without any 3rd party software

The Finder has built in video encoding and you could even use these to set up watch folders and attach a pre-set conversion using Automator if you found one setting that you prefer...
Answer: As an alternative to using Quicktime to lower the quality of the video (therefore, reduce the size of the file) is to use VLC Media Player.
It works better in the sense that it provides options for codecs, encapsulation and audio codecs as well. This can help to convert the .mov to be playable in specific devices or platforms.
Moreover, it keeps a better resolution of the videos.
Comment: This is the only option that is working for me. I tried to convert 720p files using the latest versions of iMovie, Quicktime and an old program that I used to use a lot. At 540p they created these huge files almost three times the size of the original. With VLC the new file is 75% the size of the original with really good quality.
Answer: You can transcode them while transferring!
You can do exactly same automator workflow but make it an Image Capture plug-in. So you can choose in "Image Capture" videos from your iOS device and import them transcoded.
Really easy steps are presented on macworld.com, basically you use

and import your movies using Image Capture.
If you check the box [Show this action when the workflow runs] you will be able to choose destination folder and compress options.


How does a planet lose mass to its host star?

Question: How do bodies like WASP-12b lose mass to its central body? The process is never really explained in popular media, instead showing visualisations of a thin veil of gas being "sucked" in a rather straight line (and then into a ring around the star) rising straight from the surface of the planet. I highly doubt the mechanics which these illustration insinuate: Gravitation isn't working like a vacuum cleaner on a dusty rug. Either the rug goes with it, or the dust stays on the rug. The only mechanism that I can think of are particles from the upper atmosphere which happen to pick up enough thermodynamic energy so that they are faster than the escape velocity of the planet. But is this a process which effects a big enough mass transfer to be of significance? Do I overlook something? How is such a mass defect going on really?
Comment: There is no one answer. You need to narrow your question down to particular scenarios. e.g. red giants lose mass through winds, some of which is captured; close binaries lose mass through Roche-lobe overflow; exoplanets can lose their atmospheres through heating...
Comment: It sounds like OP is asking specifically about Roche-lobe overflow.
Comment: @RobJeffries narrowed the question down to the planet/star scenario.
Comment: @Phiteros narrowed the question down to the planet/star scenario.
Answer: In the case of WASP-12b, at least, the close proximity to the star has actually deformed the planet so much that it is overflowing its Roche-lobe, the area around a planet or star that . We can show this mathematically by finding the approximate Roche-lobe of the planet using:
$\frac{r_1}{A}=.46224\sqrt[3]{\frac{M_1}{M_1+M_2}}$  for $\frac{M_1}{M_2}<.8$ (which it is)
where $A$ is the orbital separation and $r_1$ is the radius of the Roche-lobe around $M_1$.
Solving for $r_1$ we get $97788\pm 2318$ miles. The planet's radius is $77759 \pm 3909$ miles. Taking the best possible scenario, there would be $\approx$ 13,000 miles between the planet's surface and its Roche-lobe if the planet was a perfect sphere. It is unknown how much the star affects the planet, but it would not be a stretch to think that the major axis of the planet would be 13,000 miles longer than the minor axis, allowing for the planet's gas to be shoved out of the Roche-lobe and "sucked" into the star.
Comment: Could you please add an explanation of what a Roche-lobe is?
Comment: @Pavel Sure thing.


Open database with ALL discovered stars and their parameters?

Question: I am looking for an open database, obligatory an up-to-dated one, which includes all discovered stars and their parameters.
Comment: The answer is no. Your best bet if you know where the star is (or what its name is), is to interrogate SIMBAD  http://simbad.u-strasbg.fr/simbad/
Comment: It's not ALL known stars, but going through this might be a good start: https://astronomy.stackexchange.com/questions/3668/where-can-i-find-a-catalog-of-all-stars-in-the-milky-way
Comment: See GAIA in the answer to https://astronomy.stackexchange.com/questions/13488
Answer: As @ProfRob already stated, there is no single star database with all parameters. Here are some resources:

SIMBAD Astronomical Database
GAIA Archive "providing astrometry, photometry, and spectroscopy of more than 1000 million stars in the Milky Way."

A helpful and extensive collection of online resources is collected as community wiki answer to the question Where can I find the positions of the planets, stars, moons, artificial satellites, etc. and visualize them?


The appropriateness of having an 'Italian' tag (no slight intended: I've just become aware of this particular flag)

Question: Isn't having a tag such as italian inviting questions requiring at least some knowledge of Italian? Isn't 'loan-words' sufficient? Aren't cross-language questions more appropriate on Linguistics?
Comment: Since someone's going to ask, the other language tags we have are [tag:spanish], [tag:french], [tag:german], [tag:russian], [tag:portuguese], [tag:danish], [tag:swedish], [tag:hindi], [tag:chinese], [tag:japanese], [tag:korean], [tag:greek], [tag:latin], and [tag:hebrew]. Pace, Batavophones, you may be the largest unrepresented Western European language, but there are no tags for Scots, Gaelic, or Manx either, who beat you on distance.
Comment: What slight did you not intend?
Comment: I'm not anti-Italian, any more than I'm anti-Spanish, anti-French ... (thanks to the others for listing parallel tags), anti-physics etc. I wasn't singling out Italian as a special case; it was the particular tag I encountered. But I've seen one or two (rather interesting)  treatises on foreign language topics, downvoted them as flagrantly off-topic, but feel that having dedicated tags only encourages them.
Comment: Yes, with those tags, the risk is that users ask questions about Italian or other languages. Since questions on EL&U are about English, I would not add those tags. The issue is that on EL&U there are very few users who correct the wrong tags used by the users who ask questions, as if tags were untouchable.
Answer: An argument can be made (and I believe that at least one prominent EL&U contributor has made it many times) that the tags used at EL&U are completely useless and a waste of time. If so, focusing on which particular foreign language tag(s) should be dumped is rather like trying to to decide which particular deck chair(s) to throw overboard now that a collision with an iceberg seems inevitable.
My view of tags is that they can be helpful in noting particular areas of relevance within a question. For example, a memorable question posted in 2015 asks where, when, and under what circumstances the U.S. English term "pizza pie" originated. Since the word pizza by itself is of Italian origin, it would seem reasonable for the poster to have included a tag for "italian" among the other tags (which currently consist of "etymology," "american-english," and "food").
Although I am broadly interested in the English language's amoeba-like ingestion of words from other languages, I am particularly interested in instances where the appropriated words have undergone some degree of transformation in the course of their incorporation into the body of popular English. In such cases, having a tag that identifies the source of the appropriation as "italian" (or "yiddish" or whatever it is) may be quite useful to readers whose etymological interest doesn't extend to all source languages.
On a more general note, I think it is worthwhile to appraise the value of tags not in isolation but in the context of other tags that may appear in the same question. The fact that posters are permitted to include as many as five tags with a question suggests to me that the people who adopted that policy imagined that posters might use some tags to refine others—as might happen when someone uses a tag such as "italian" to provide greater specificity to a more broadly applicable tag such as "etymology."
Comment: You convinced me. Due to what must have been a slip of mind,  I've just edited the pizza pie question and added the Italian tag. Makes perfect sense.
Comment: I've just discovered that 'Greek' and 'Latin' tags exist. I've just checked the 'first' 100 questions with the 'etymology' tag, and found that only 2½ (I've allowed ½ for AAVE) of them have an additional foreign-language tag. It does seem odd that enquirers can determine that a word is say a French loanword (other lovely languages exist) but are enquiring about the French connection. // To forestall forays into off-topic comparisons with other languages (or even 'FLU'-worthy answers), perhaps 'ex-French' etc tags might be an idea.
Answer: My understanding, and use, of tags differs from what is suggested by your question. I apply tags after composing the question, primarily as a means of facilitating the attention of others who might be interested in answering the question, or at least interested in reading it.
Your question seems to be primarily an expression of your disinterest in etymology questions, or questions involving other specific languages but not centered on that other language; many questions tagged etymology might want a specific-language-other-than-vanilla-english (hereafter called slotve)content or subject tag, because that other language (or dialect; Scottish, for example, is sometimes considered a dialect) might be, or be said to be, a source, supply an etymon, etc.
So no, I don't think questions with slotve are "invited" by the tag; no, I don't think loan-words is entirely sufficient for everybody's purposes here; and no, cross-language questions about English etymology (among other subjects bearing on English usage) may not be more appropriate on Linguistics.
I seem to recall (through a veil of mild indifference) that it has been established on ELU Meta that there is some disagreement among ELU participants about whether or not etymology (or phrase-origin, etc.) questions are on-topic. This disagreement is sometimes reflected in overly aggressive close-voting by participants with little or no interest in, or expertise on, the topic. I also seem to recall that the perfectly good suggestion for dealing with these circumstances is for those with little or no interest in, or expertise on, a topic to recuse themselves from close-voting questions on such topics.
Whether or not I personally use a tag, have an interest in, or expertise on, a topic, I don't see attempts to do an end-run around disagreement about whether the topic is on-topic at ELU by foreclosing on tags that might be useful to those who do have such an interest, or systematically close-voting questions about the topic, as at all legitimate. Neither are such attempts, at least with respect to foreclosed tags, likely to be successful, because anybody with a certain reputation is likely to simply add the slotve tag back in if they think it's salient.
By way of example, I note that 10 of the 32 questions now tagged italian are also tagged etymology; 13 of the 80 questions tagged german; 9 of the 64 questions tagged spanish; etc. The translation tag also frequently co-occurs with slotve.
Comment: It took me about a minute to understand the "slotve" tag. Now I feel like the people with flat foreheads who live close to the Niagra Falls. You know, the ones that wake up every morning and say: "What _is_ that noise? Oh, _right_, now I remember..."
Comment: I've looked through about 10 of the 32. I've removed the 'Italian' tag from one ('nb is from the Italian ...') and CV-d a couple ('lei' [not Hawaiian] is not in the lexicon; ...), and find some very dubious as fitting on ELU. However, I concede that the 'Italian' tag remains very appropriate for the odd post. But I have in mind about 10 lines of Italian etymology in one post.
Comment: 'Your question seems to be primarily an expression of your disinterest in etymology questions' is personal invective. You're implying that I'm complaining about questions concerning etymology on ELU: obviously anti-site-policy. Etymology questions are fine. The usual short dictionary etymologies ('from Old French ...') are fine (but probably LMGTFY).  Ten lines in an answer showing the previous development of a word in say Portuguese is not.
Comment: @EdwinAshworth, "LMGTFY" = "let me google that for you"...I guess I could be expected to know that. You're not doing what you appear to be, that is, implying that short (one line) etymologies are okay, but 10 lines are not? Likewise with valuing Old French etymologies but not Portuguese? In either case, I would think that the pertinence of the etymological source language to a word's adoption and development in English, however long, concerning whichever language, is most important, not arbitrary length or specific source language requirements.
Comment: Here is a question I feel should be closed: [How to translate fac...ties-de-descendre from French in the context of a board game](https://english.stackexchange.com/questions/542939/how-to-translate-fac%c3%a9ties-de-descendre-from-french-in-the-context-of-a-board-g) [French tag]. And at [What lies behind the etymology of the word dandelion?](https://english.stackexchange.com/questions/401122/what-lies-behind-the-etymology-of-the-word-dandelion) is a sizeable quote from 'a French etymology dictionary'. _I'm not querying this question, merely the wisdom of having the 'French' (etc) tag._
Comment: @EdwinAshworth, I'm not sure what's left to discuss. The central issue is perhaps that you feel the existence of a tag "invites" or encourages off-topic questions. That's hard to absolutely deny with a straight face, although I think the scope of any such invitation or encouragement is less than concerning; additionally, as I mentioned in the answer, the invitation or encouragement is after the fact for those who approach tags as *tags*.


Belief in Ghost and spirits

Question: If Buddhists don't believe that we have a soul then why do some believe in ghosts or spirits? this seems contradictory.
Answer: Soul in the context of Buddhism is that was contemporary considers atman, which is permanent, pleasant and controllable. What is established in Buddhism is that there is nothing as such and everything constituting a being is subjected to the 3 Universal Characteristics.
Also there is not entity as a being. What is there is a causality arising process, which also is presented as the 4 Noble Truths, Dependent Origination, Conditional Relations. The continuity of the causality process can be taken as a trip in a vehicle. Each point of the journey is different from the other but still point of the same journey, hence there is a continuity but not also the entirely the same. Death is like changing vehicles.
In Buddhism Ghosts and Spirits are not tormented souls of past being. They themselves are life forms which inhabit the 31 planes of existence. When one dies and is reborn as a Ghost or Spirit this is like any other rebirth. This is a new existence. It is not the same being in the previous birth or nor a different being, but the continuation of the causality process.
Answer: In buddhism, nothing is permanent. One can be reborn as an animal, reborn as a ghost, reborn in hell, reborn as a god thus cycling through all 6 realms of birth. Therefore, there can't be one soul, otherwise there'll be  animal soul when animal dies,  human dies there will be human soul, a ghost dies there will be ghost soul, a god dies there will be god soul and thus 6 different souls - and not one soul. Thus there is no soul, just cycle through the 6 realms.
Comment: So then what gets reborn?
Comment: Mental continuum gets reborn. What one did in the past gets propagated in the future. This propagation is perceived by the mental continuum as rebirth. As long as one creates karma, there is rebirth.

Belief in Ghost and spirits


How do you make an NN for image classification invariant to translation **and** rotation?

Question: CNN are (I think) invariant to small translations of the input image, i.e., they will classify to the same class an image $X$ and an image $X'$ such that all pixels have been translated along a vector $\mathbf{v}$ by some "small" distance $d$. They're not, however, invariant to rotation. I.e., if $X'$ is obtained by $X$ applying a rotation of arbitrary degree $\theta$ around an axis $z$ orthogonal to the plane of the image, they won't necessarily classify it to the same class as $X$. Practitioners usually solve this by data augmentation, but this is unnecessarily wasteful and anyway not an option in my case. Is there a way to make the NN architecture invariant to both isometries? I don't have to use a CNN, but since CNN already enjoy some sort of translation invariance, I figured it would be easier to modify them to get rotational invariance , than to use a completely different architecture.
Answer: It is not possible to have general rotationally-invariant neural network architecture for a CNN*. In fact CNNs are not strongly translation invariant, except due to pooling - instead they combine a little bit of translation invariance with translation equivariance. There is no equivalent to pooling layers that would reduce the effect of rotation this way (although for very small rotations the translation invariance will still help).
You can however construct features and create a pipeline that reduces incoming rotation differences in your inputs. For example, this answer on Signal Processing Stack Exchange suggests calculating dominant gradient of an image, then rotating the image so that this is always oriented the same way before further processing. If your image has strong straight edges, you could do similar by detecting those (e.g. by using a Hough transform) and rotating the input so that these are always oriented the same way. These approaches work only within certain image tasks, but can save on processing time and potentially increase accuracy if they are possible. Effectively they are a form of input normalisation.
A more radical idea might be to perform a map to polar co-ordinates in your image before processing. This would effectively convert rotational (and radial) variance into translation variance in your image. A CNN processing this mapped image would effectively convert its translation invariance into rotational invariance on the original unmapped image. But the cost would be losing all translation invariance, so only worth considering if your inputs have high variance in rotation but low variance in translation.

* Never say never. This is caveated by special cases, for example the paper Group Equivariant Convolutional Networks explains an architecture that adds support for multiples of 90 degree rotation (taking advantage of grid structure in computer images and the weight matrices that construct neural network layers). However, if you want to support free rotation of values other than 90, 180, 270 degrees, then as far as I know, there is no way to do that architecturally within the network.
Comment: I would like to add that there are convolutional architectures that have specific rotation equivariances, for example 90, 180 and 270 degrees. See: https://arxiv.org/abs/1602.07576
Comment: I didn't know about the equivarance concept: I'll study your link. Will also look into Hough transform. Using equivariance as a search word, I found this: https://arxiv.org/pdf/1612.04642.pdf It's very complex for me. It seems to preserve both translational  & rotational equivarance . What do you think, will it work? I can open a new question if you want.
Comment: @DeltaIV: The paper is too advanced for me, too, but might help you with your problem. Perhaps someone else could answer here using details from the paper, or if you dig into the paper and get stuck. One thing to note - equivariance can help with reducing number of parameters required (it's essentially a core concept to explain why CNNs perform well), but it doesn't always help with every problem.
Answer: Please see 3 recent pre-prints (6-8/2018) about transformation-identical CNN (TI-CNN) and geared rotation-identical CNN (GRI-CNN). They were expanded and derived from the circular path CNN (SPIE MI 1998 and IEEE TMI 2002) initiated by the same medical AI research team at Georgetown University medical center who also independently developed the CNN and the wavelet CNN in early 1990s for cancer research.
"Transformationally Identical and Invariant Convolutional Neural Networks through Symmetric Element Operators"
https://arxiv.org/abs/1806.03636
"Transformationally Identical and Invariant Convolutional Neural Networks by Combining Symmetric Operations or Input Vectors"
https://arxiv.org/abs/1807.11156
"Geared Rotationally Identical and Invariant Convolutional Neural Network Systems"
https://arxiv.org/abs/1808.01280 also


Should there be more explanations given in close votes

Question: There were two close votes on question 41667 when I added mine, but there was no explanation given in the comments as to why the close votes were cast. Since a user has to have 250 reputation to see close votes, might this mean that if we close votes without comments, that we're closing questions where the user asking the question does not see the reason that close votes are being cast? If so, is this the way we want it?
Comment: @Flimzy Seems like you are right. [Having 250 rep or better "allows you to view and cast close and reopen votes on your own questions."](http://christianity.stackexchange.com/help/privileges/view-close-votes) I'm not sure I see any logic in that. I might ask on MSE.
Comment: @brasshat, given the variety of responses you've gotten, I think it'd help a lot if you clarified what you're asking.
Comment: @ El'endia Starman, the first paragraph of Fredsbend's answer pretty clearly states my position at the moment: it is charitable if one makes a close vote, especially if it is the first close vote, or if on is voting to close for a reason others have not previously cited when they voted to close, to add a comment explaining the vote. And I further think it charitable, when possible, to offer guidance to the user whose question is under consideration, as to what might make the question fall within the scope.
Comment: I think you can see close vote counts on your own questions, despite rep count.
Comment: Okay, thanks for the clarification. I'll edit my answer accordingly.
Comment: @fredsbend: I don't believe that's true. I recently had a question closed on another site where I have very low rep, and saw no close votes until the question was closed.
Comment: @fredsbend: I think I've seen it discussed on MSE before, but I agree, there's not much logic in it.
Answer: I think some actions should be commented. Close voting is one of them. It's not required, but it's just polite. It's also better for the site and will help retain quality contributors.
SE is a confusing platform. It's unique and there's a lot going on. I think many of us who have been around a while take for granted how easily we now stroll along through the site.
Having your question "closed" is a foreign concept to most people. "You mean you won't even let people answer my question? It's not that bad!" They deserve a reason better than the cookie cutter responses in the close dialog. More than that, they need a name to ask for help, because the existence of meta is not apparent either.
Lot's of new users are drive-by's. They will just swing by when googling for something else, decide they have a question of their own, ask it, then never come back to even check on it. Others read for a while and get it before they even ask a question. Then there's others in between that we could sink as regulars if the right things come together at the right time for them. That takes direction. People like to be helped when they're confused, and let's face the facts, SE is quite confusing to a newbie.
Answer: I just took a look at the front page of Physics.SE, where I currently have 235 reputation, and I can see that this question was closed as "unclear what you're asking". The 250-rep limitation applies only to seeing the close votes (e.g. 1 "duplicate", 1 "off-topic", 2 "primarily opinion based") and not the close reason after the question has been closed.
I am sometimes guilty of closing without a comment, but sometimes the close reason says what I want to say, so I feel like there's little reason to repeat it.

EDIT: upon clarification, I see the question is really more about the courtesy of commenting on a new user's question to explain why their question is being closed and/or help them fix it up. In that case, I agree that this is a good thing. It is good and courteous to help a new user understand how this site works and why certain actions are being taken.
That said, I'm lazy. I know that there's a tool that fredsbend, David Stratton, and Caleb (I think) at least use to type in pre-written comments. I don't use that tool, so I comment less often and with less to say. Quite often, the question is pretty poor and I feel like if the user put that little effort into the question, I'm not going to waste my time writing out a good explanation/educational comment. That's how I do things, but otherwise, I support the idea of commenting more often.
Comment: I don't think he's talking about the reason once closed, but the close vote count before it's closed. I could be wrong.


What local resources are used when bruteforcing a remote service?

Question: What pc resources are used when bruteforcing ?
I mean bruteforcing something online, not hashes.
Do you need a good amount a RAM and a good CPU or it's just about the internet speed ?
Comment: *"I mean bruteforcing something online"* What, specifically? The answer may be different for bruteforcing a username/password login, versus bruteforcing credit card transactions, vs anything else.
Answer: Well, unless the site you are bruteforcing is potato, it will have rate limits locking you out after a few attempts. So the biggest resource will be the number of IP addresses you can get, to circumvent the lockout. (assuming IP is used to block)
If there is no limit, then it will likely be internet speed. Though under some extremely rare circumstances, it may be something else.
Comment: @Suppen Yes, but that brings its own problems - it's basically a free DoS attack on the site. A simple "one login per second" is usually a lot better compromise between security and *actually being able to use the service* :D
Comment: One of the only "extremely rare circumstances" I can think of is having physical access to the network the servers are on to connect to it directly with Ethernet, but I think getting the hashes would be easier than that...
Comment: Well, I was actually thinking something like the SCRAM protocol, where the client has to do pbkdf2 on his end, or even a variant with argon2 with high memory usage.
Comment: Some sites will lock the account instead of blocking the IP after a number of tries. In that case, no amount of IP-addresses will help. You will also get no further with a supercomputer than a raspberry pi


How can two electrons repel if it's impossible for free electrons to absorb or emit energy?

Question: There is no acceptable/viable mechanism for a free electron to absorb or emit energy, without violating energy or momentum conservation. So its wavefunction cannot collapse into becoming a particle, right? How do 2 free electrons repel each other then?
Comment: "There is no known mechanism for free electron to absorb or emit energy"? Who said that?
Comment: if your concern is that repelling is cause by the exchange of virtual photons, and a free electron can neither absorb nor emit a photon with violating conversation laws, then don't worry: virtual photons are off shell--they have the energy and momentum required to converse energy and momentum. Unless you are using old fashioned perturbation theory, then energy is violated, but only briefly.
Comment: @knzhou: it will violate simultaneous conservation of momentum and energy
Comment: [Free electron can't absorb a photon](https://physics.stackexchange.com/questions/225522/free-electron-cant-absorb-a-photon) and [can a free particle absorb emit photons](https://physics.stackexchange.com/questions/81448/can-a-free-particle-absorb-emit-photons)
Comment: imagine a high energy photon hits an electron at rest, my frame is wavelength becomes longer and electron still remains at rest but from zero-momentum frame photon wavelength remains the same except the electron accelerates? what is this zero-momentum frame? too confuse right now!!!
Answer: It is true that the reactions
$$e + \gamma \to e, \quad e \to e + \gamma$$
cannot occur without violating energy or momentum conservation. But that doesn't mean that electrons can't interact with anything! For example, scattering
$$e + \gamma \to e + \gamma$$
is perfectly allowed. And a classical electromagnetic field is built out of many photons, so the interaction of an electron with such a field can be thought of as an interaction with many photons at once. There are plenty of ways a free electron can interact without violating energy or momentum conservation, so there's no problem here.
Answer: To resolve this paradox requires study of time dependent perturbation theory; solving Schrodinger's equation with a time dependent perturbation corresponding to the interaction time of two particles.
If you do this you arrive at the following conclusions:
A single free electron cannot absorb a free photon ( $e + \gamma \to e$ is not a valid interaction)
A single free electron cannot emit a free photon ( $e \to e + \gamma$ is not a valid interaction)
However, two electrons can scatter by exchange of energy ( $ e + e \to e + e$ is a valid interaction)
In this later case it is common to refer to this process being due to exchange of "a  virtual photon" between the two electrons. But this is just a description of the calculation of time dependent perturbation theory.
Answer: Basically, because the process doesn't simultaneously conserve energy and momentum; this is why we say that it's mediated by a virtual photon.
In more technical language, this means that the photons that are exchanged between two interacting electrons are allowed to be "off shell", where the "shell" is the relationship $E^2 = p^2c^2$ (for a massless particle). Real particles are required to be on-shell, but virtual particles are allowed to stray from that condition, at least by some amount.
In the Feynman-diagram description of the scattering between two electrons you often find diagrams where one electron emits a photon which is then absorbed by the other; this is a virtual photon and as such both the 'emission' and 'absorption' processes are exempt from these considerations.
As always, though, it bears repeating that Feynman diagrams are calculational tools, and none of the virtual particles that appear in those diagrams actually physically exist in any definable sense. The fact that the 'emission' and 'absorption' processes, as well as the virtual photon itself, seem to defy energy or momentum conservation is purely a quirk of the way in which we've chosen to interpret limited chunks of our calculation.
Answer: Your first statement is false: energy can indeed be added at will to electrons by accelerating them with electrostatic charge distributions, as for example in the case of rapidly varying radio frequency (electromagnetic) fields. Neither energy nor momentum conservation is violated in this case. Search on SLAC for more details about this.
Your other questions are unclear. I recommend you do the search, read a bit, and return here if you have further questions.
Comment: i know when electron in an atom absorb energy it becomes excited, as it goes from excited to lower state energy is being released as photon and in ur case it is radiowave. However I'm at a loss when I try imagine 2 free electrons (particle/wave) can repell each other?
Comment: @BillAlsept: I'm referring to free electron not valence electron
Comment: @user6760 The free electron can also gain energy from photon. That also leads to a measurement problem.
Comment: @user6760 if you fire free electrons through a double slit experiment and try to observe them, the photons will physically interfere.
Comment: @BillAlsept: of course 1 free electron interacts with one atom
Comment: @user6760 you said "there is no acceptable/viable mechanism for a free electron to absorb energy" Photons interacting with free electrons, it's part of the problem of measurement in a slit experiment. And as you just pointed out atoms can also transfer energy to an electron. Anything with momentum can.  Also you should look up synchrotron
Comment: @BillAlsept: I'm still confused can you expand it into an answer, thanks and sorry for the trouble.
Comment: Re "search on SLAC", if you've been around computers for a while, you will remember CRT displays & TV sets.  Those work by accelerating electrons, too.
Comment: @jamesqf, of course- but SLAC is way cooler because of how big it is, and the fact that I grew up across the bay from it ;-)
Comment: @jamesqf: I guess crt display works by using electric field to direct (not accelerate aka change in speed) the electrons that are popping out from the source, right now I'm finding out if the electrons in the beam repell each other...
Comment: @user6760: Well, you can't direct the electrons without accelerating them - using the physics definition of the word, of course.  And if they weren't somehow accelerated, then when they popped out from the source, wouldn't they go in random directions, instead of a nice collimated beam?
Comment: @jamespf: agreed actually I don't know how the popping of electron in the field works so maybe I will add to my collection of questions to be asked.
Answer: Let me start with a simple counter-question. How a free electron in a laser cooling process loses kinetic energy? The photon, hitting the compliant electron, gets absorbed and after is re-emitted with a higher frequency (with a higher energy content).

There is no acceptable/viable mechanism for a free electron to absorb or emit energy,...

There is. Photons are indivisible particles only between their emission and absorption. And the term photons is a summary for a class of particles over all possible frequencies (energy contents). So the re-emission of a photon mostly happens not with the same frequency as the absorbed photon.
So I rewrite the equation from another answer to an interaction between the electron and the photon:
$$e + \gamma \equiv e \leftrightarrow (\gamma_1 + \gamma_2) \to (e + \gamma_1) + \gamma_2 $$

How do 2 free electrons repel each other then?

Beside explanations with virtual photons another explanation is that for equaly charged particles the fields do not exchange energy but work like springs. The electric fields get deformed like springs and get relaxed after by pushing the particles back. But the particles lose meanwhile some amount of their kinetic energy (in relation to each over) by emitting photons. You remember, any acceleration is accompanied by photon emission.


What does Paul mean by saying "I die daily" in 1 Corinthians 15:31?

Question: When Paul says "I face death everyday" in 1 Corinthians 15:31, what does he mean by this? What will be the best way to interpret that scripture?
Comment: To 'face death everyday' is no more than we all do, every moment of every day, for we are mortal and 'we know not what a day may bring forth'. But Paul says 'I die daily' καθ ημεραν αποθνησκω, which is another thing altogether. For Paul also says 'I am crucified with Christ'.
Comment: You can edit the body of your question to reflect your title.
Answer: I want to applaud you, OP, for including two different translations of the verse in question. "I die daily" seems to be a more literal translation of the Greek, but "I face death everyday" seems to convey the sense better.
Note that, in the context of Corinthians 15, Paul is speaking about the resurrection of the dead. He is essentially asking, "If there's no afterlife, why are we wasting our time suffering here on Earth as Christians? Why don't we just live it up?"

(Corinthians 15:29-34, DRB) Otherwise what shall they do that are baptized for the dead, if the dead rise not again at all? why are they then baptized for them? Why also are we in danger every hour? I die daily, I protest by your glory, brethren, which I have in Christ Jesus our Lord. If (according to man) I fought with beasts at Ephesus, what doth it profit me, if the dead rise not again? Let us eat and drink, for to morrow we shall die. Be not seduced: Evil communications corrupt good manners. Awake, ye just, and sin not. For some have not the knowledge of God, I speak it to your shame.

If we look at the context of the verse in question, especially the bolded part, it appears that Paul is alluding to his persecution as a Christian when he says "I die daily." (Christians were in danger of being martyred like Stephen)
It seems then, that Paul meant:

I'm in danger of death daily because of my faith

and/or

I'm suffering every day because of my faith

In his Commentary on 1 Corinthians, Thomas Aquinas seems to think that Paul means "I'm in danger of death daily" when he says "I die daily." I suspect, however, that Paul might have also been referring to his suffering persecution in general. (The two possibilities are not mutually exclusive.)
It reminds me of how St. Thecla is venerated as the first female "martyr." According to her hagiography, she was almost martyred multiple times, but her life was miraculously preserved. The point is that, while not physically being martyred, she is venerated as a "martyr" because she faced imminent death and was willing to die rather than deny Christ.

The image depicts St. Thecla receiving the crown of martyrdom from heaven despite surviving the lions.

PART TWO: THE SCRUPULOUSLY HYPERLITERAL INTERPRETATION
But, hold the phone! Paul said he "dies daily" even though he doesn't! The Bible must be a book of lies because not every word is literally true! Right?
Ummm, actually there is a sense in which the verse is literally true.
Since the present tense in Koine Greek can either have a simple or a progressive aspect, depending on the context, Paul could be saying "I am dying daily." And this would be literally true! I mean, Paul is shortening his lifespan by being a Christian. (Extra-biblical writings suggest he was eventually beheaded.) In fact, everyone is "dying" at least due to age.
No contradiction :)
Comment: It says in the Bible that we will be saved if we confess Christ as Lord. It doesn't say that we are saved if we do that, only that we will be saved; if we practice our conviction, that is. Jesus: "Not all who says "Lord, Lord" will enter the Kingdom of God, but only those who do the will of the Father. Jesus also said that blasphemy against the Father, or the Son, will be forgiven, but blasphemy against the Holy Spirit will not. Based on the above, it seems that if someone happens to deny Christ under torture salvation would, as long as charity and chastity are held holy, not be cancelled.
Comment: This would, of course, just apply to immature Christians. These will get a second change to martyrdom later on. The risk is, however, that the limited number of wedding guest seats gets filled up, the door closes, and one misses out.
Answer: Quoting a little more of the passage for context:

And why stand we in jeopardy every hour? I protest by your rejoicing which I have in Christ Jesus our Lord, I die daily. If after the manner of men I have fought with beasts at Ephesus, what advantageth it me, if the dead rise not? let us eat and drink; for to morrow we die.
  -- 1 Corinthians 15:30-32 (KJV)

Expressions such as "Why stand we in jeopardy every hour?" and "I have fought with beasts at Ephesus"(1) indicate that Paul is referring to physical threats upon his life, which the record of Acts confirms to be true:

At Damascus

And after that many days were fulfilled, the Jews took counsel to kill him: But their laying await was known of Saul. And they watched the gates day and night to kill him.
  -- Acts 9:23-24 (KJV)

At Antioch

But the Jews stirred up the devout and honourable women, and the chief men of the city, and raised persecution against Paul and Barnabas, and expelled them out of their coasts.
  -- Acts 13:50 (KJV)

At Lycaonia

And there came thither certain Jews from Antioch and Iconium, who persuaded the people, and, having stoned Paul, drew him out of the city, supposing he had been dead.
  -- Acts 14:19 (KJV)

At Philippi

And when her masters saw that the hope of their gains was gone, they caught Paul and Silas, and drew them into the marketplace unto the rulers, … And the multitude rose up together against them: and the magistrates rent off their clothes, and commanded to beat them.
  -- Acts 16:19,22 (KJV)

At Thessalonica

And some of them believed, and consorted with Paul and Silas; and of the devout Greeks a great multitude, and of the chief women not a few. But the Jews which believed not, moved with envy, took unto them certain lewd fellows of the baser sort, and gathered a company, and set all the city on an uproar, and assaulted the house of Jason, and sought to bring them out to the people.
  -- Acts 17:4-5 (KJV)

At Berea

But when the Jews of Thessalonica had knowledge that the word of God was preached of Paul at Berea, they came thither also, and stirred up the people.
  -- Acts 17:13 (KJV)

At Corinth

And when Gallio was the deputy of Achaia, the Jews made insurrection with one accord against Paul, and brought him to the judgment seat,
  -- Acts 18:12 (KJV)

At Ephesus

Moreover ye see and hear, that not alone at Ephesus, but almost throughout all Asia, this Paul hath persuaded and turned away much people, saying that they be no gods, which are made with hands: … And when they heard these sayings, they were full of wrath, and cried out, saying, Great is Diana of the Ephesians.
  -- Acts 19:26,28 (KJV)

At Jerusalem

And all the city was moved, and the people ran together: and they took Paul, and drew him out of the temple: and forthwith the doors were shut. And as they went about to kill him, tidings came unto the chief captain of the band, that all Jerusalem was in an uproar.
  -- Acts 21:30-31 (KJV)
And when it was day, certain of the Jews banded together, and bound themselves under a curse, saying that they would neither eat nor drink till they had killed Paul.
  -- Acts 23:12 (KJV)

This occurred around 59 AD(2) , which meant that from that time forward Paul's life was under constant threat of death wherever he went. However, his trust in Jesus to complete the task he set before him was such that he gave little heed to it.
At Caesarea

And when they had been there many days, Festus declared Paul's cause unto the king, saying, There is a certain man left in bonds by Felix: About whom, when I was at Jerusalem, the chief priests and the elders of the Jews informed me, desiring to have judgment against him. To whom I answered, It is not the manner of the Romans to deliver any man to die, before that he which is accused have the accusers face to face, and have licence to answer for himself concerning the crime laid against him.
  -- Acts 25:14-16 (KJV)

At Sea

And we being exceedingly tossed with a tempest, the next day they lightened the ship; And the third day we cast out with our own hands the tackling of the ship. And when neither sun nor stars in many days appeared, and no small tempest lay on us, all hope that we should be saved was then taken away.
  -- Acts 27:18-20 (KJV)

At Melita (Malta)

And when Paul had gathered a bundle of sticks, and laid them on the fire, there came a viper out of the heat, and fastened on his hand. … And he shook off the beast into the fire, and felt no harm. Howbeit they looked when he should have swollen, or fallen down dead suddenly: but after they had looked a great while, and saw no harm come to him, they changed their minds, and said that he was a god.
  Acts 28:3,5-6 (KJV)

Paul appealed to the Roman church for prayer:

Now I beseech you, brethren, for the Lord Jesus Christ's sake, and for the love of the Spirit, that ye strive together with me in your prayers to God for me; That I may be delivered from them that do not believe in Judaea; and that my service which I have for Jerusalem may be accepted of the saints;
  -- Romans 15:30-31 (KJV)

Paul spoke of the need for "boldness" in proclaiming the Gospel:

And many of the brethren in the Lord, waxing confident by my bonds, are much more bold to speak the word without fear.
  -- Philippians 1:14 (KJV)
But even after that we had suffered before, and were shamefully entreated, as ye know, at Philippi, we were bold in our God to speak unto you the gospel of God with much contention.
  -- 1 Thessalonians 2:2 (KJV)

Paul was literally on the bleeding edge of the Gospel, and in his experience and expectation, the threat of physical death was a daily consideration.

We are troubled on every side, yet not distressed; we are perplexed, but not in despair; Persecuted, but not forsaken; cast down, but not destroyed; Always bearing about in the body the dying of the Lord Jesus, that the life also of Jesus might be made manifest in our body. For we which live are alway(3) delivered unto death for Jesus' sake, that the life also of Jesus might be made manifest in our mortal flesh. So then death worketh in us, but life in you.
  -- 2 Corinthians 4:8-12 (KJV)

Notes:

The Greek word here is θηριομαχέω (Strong's G2341 - thēriomacheō), which is a compound of θηρίον (Strong's G2342 - thērion) and μάχομαι (Strong's G3164 - machomai). Paul's only other use of θηρίον is in his letter to Titus where he quotes an anonymous Creatian prophet who refers to Cretians as "alway liars, evil beasts" (Titus 1:12). It is highly likely then that the beasts Paul was referring to were the men he encountered at Ephesus, those native to the area who handled him roughly, and the Jews who moved them to do so.
BibleHub timeline
Thayer: perpetually, incessantly, invariably; Strong: always, ever, regularly (Studylight Lexicon)
Comment: Woe, enegue, that is an awesome answer! It's the kind of answer I want to frame and hang on my wall! +1 way up!
Comment: There is a difference between "dying daily" and being frequently threatened with death.
Answer: I believe that what Paul was saying is found in Gal 2.20
"I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh
Sin is anything that goes against God's will and His laws. To commit sin is to transgress or disobey these laws. The lust to sin dwells in human nature. In other words, it is contaminated and motivated by the sinful ...
 I live by faith in the Son of God, who loved me and gave Himself for me." Galatians 2:20.
In text emphasis not mine, but i agree with the writer, Paul yes faced death multiple times and even said to Agabus that he was not only ready to be bound but to also die, but i think to die daily Paul was talking more about dealing with his fleshly desires on a daily basis. He was talking more about his daily experiences as a believer understanding that it is one thing to proffess christ its another thing to live for him
Answer: It simply meant we die daily to the old man everyday as we put on the new man.
Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
Romans 6:6
Comment: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).
Answer: In context, Paul is addressing those who question the resurrection of the dead. His argument is initially circular: if there was no resurrection of the dead, then there would be no point in proclaiming that Christ is risen, because he cannot have been raised if it were not true. He also questions: what would be the point in baptising in the name of some man who is not living?
Continuing in this vein, Paul then asks why he faces death (ie. risks his life confidently and without fear) if there is no hope in the dead being raised:

And as for us, why do we endanger ourselves every hour? I face death
  every day—yes, just as surely as I boast about you in Christ Jesus our
  Lord. If I fought wild beasts in Ephesus with no more than human
  hopes, what have I gained? If the dead are not raised, "Let us eat and
  drink, for tomorrow we die." 1 Corinthians 15: 30-32

Was Paul facing death everyday?
Paul backs up his argument with his own actions: disregarding the demands of the flesh and the fear and avoidance of death, and instead risking or facing death by continuing to preach in the name of Jesus, even though people were plotting to have him killed. This is not simply having threats on his life, but behaving in a way that treats those threats as inconsequential. The details of Paul's death-defying behaviour are described in Acts:

Then some Jews came from Antioch and Iconium and won the crowd over.
  They stoned Paul and dragged him outside the city, thinking he was
  dead. But after the disciples had gathered around him, he got up and
  went back into the city. Acts 14: 19-20
Then Paul answered, "Why are you weeping and breaking my heart? I am
  ready not only to be bound, but also to die in Jerusalem for the name
  of the Lord Jesus." Acts 21: 13

But he appears to more specifically refer to the riot at Ephesus:

Soon the whole city was in an uproar. The people seized Gaius and
  Aristarchus, Paul's traveling companions from Macedonia, and all of
  them rushed into the theater together. Paul wanted to appear before
  the crowd, but the disciples would not let him. Even some of the
  officials of the province, friends of Paul, sent him a message begging
  him not to venture into the theater. Acts 19: 29-31

Life and death in the flesh vs resurrection and eternal life in the spirit
Paul's writings refer to a dichotomy between life in the spirit which is eternal (as confirmed by the resurrection), and life in the flesh, in which we are ruled by sin and death, and which ends in death.
In 1 Corinthians, he argues that if there is no resurrection, then we continue to fear death as if in death we will cease to exist, and nothing has changed - there is no good news to preach. We continue to be ruled by our avoidance of death, our instincts to survive, benefit materially and regenerate ourselves ('no more than human hopes'), obeying the demands of the flesh despite the law, which cannot free us from sin but instead binds us to sin and to this flesh (which will inevitably perish).

The mind governed by the flesh is death, but the mind governed by the
  Spirit is life and peace. The mind governed by the flesh is hostile to
  God; it does not submit to God's law, nor can it do so. Those who are
  in the realm of the flesh cannot please God. Romans 8: 6-8

But by faith in Jesus' death in the flesh and his subsequent 'resurrection' in the spirit, Paul believes that Jesus demonstrated a different way to live: a life in the spirit, where death is no longer to be feared as an end, but simply the point at which one is fully released from the demands of the flesh.

But if Christ is in you, then even though your body is subject to
  death because of sin, the Spirit gives life because of righteousness.
  Romans 8:10
For if we have been united with him in a death like his, we will
  certainly also be united with him in a resurrection like his. For we
  know that our old self was crucified with him so that the body ruled
  by sin might be done away with, that we should no longer be slaves to
  sin— because anyone who has died has been set free from sin. Romans 6:
  5-7

In following this example, a believer's life is not in the flesh or in what can be observed, held or possessed, but in their spiritual connection with each other and with God's unconditional love for all creation - and it is in this life that Jesus continues to live and interact with believers.
God's love and life in the spirit
In Romans, Paul quotes a similar phrase from Psalm 44 in expressing this confidence that this love of God is not hindered by death:

Who shall separate us from the love of Christ? Shall trouble or
  hardship or persecution or famine or nakedness or danger or sword? As
  it is written: "For your sake we face death all day long; we are
  considered as sheep to be slaughtered." No, in all these things we are
  more than conquerors through him who loved us. For I am convinced that
  neither death nor life, neither angels nor demons, neither the present
  nor the future, nor any powers, neither height nor depth, nor anything
  else in all creation, will be able to separate us from the love of God
  that is in Christ Jesus our Lord. Romans 8: 35-39

So Paul was prepared to face his own death every day, because he believed that it was his life in the spirit, in connecting others to Jesus' resurrection and to God's love, that would also be 'resurrected' and ultimately endure beyond his death.


What is this grass-like plant?

Question: What is this plant? I could not find anything.
Comment: As this grass gets older you should see glints of orange at the ends of the leaves.  Absolutely gorgeous in big groupings.  Not as invasive as mexican feather grass but you'll find babies popping up now and then.  At the price these go for, you'll want to transplant them into your landscape.  Let us know when you see seed heads or coloring.  Definitely a garden plant versus indoors.  Perfect for spicing up your potted plants.  Prune by gathering straight up into a 'pony tail' and cut straight across, release and ta da!
Answer: Judging by its upright habit, maybe Calamagrostis 'Karl Foerster' without its flowers/seedheads http://plants.gertens.com/12070009/Plant/2170/Karl_Foerster_Reed_Grass, otherwise Carex elata 'Aurea', though that one has leaves which tend to curl over gracefully.
A clearer image, without a plant directly behind it, which shows more detail of the foliage might confirm or deny the ID.
UPDATE - its not Carex, so more likely Calamagrostis, which is commonly known as a reed grass. Hard to be certain without the presence of flowers or seedheads though, and if its been indoors for some months, that makes it harder - Calamagrostis usually dies back in winter in cooler regions, but won't have done that indoors - its not usually grown as a houseplant.
Answer: This is too young to tell right now over a photo.  I've got two others that I dearly love, one being voraciously invasive but hell...that is Mexican Feather Grass; Stipa tenuissima.  The other is Orange Sedge; Carex testacea.  I looked up the pics on the internet and I disagree with the pictures of Orange sedge...light green with orange tints, tips.  This plant is not bronze at all!!![Carex testacea
]1

What is this grass-like plant?


Trim a shape in Inkscape

Question: I am drawing a geometric pattern in inkscape. I have faced a problem. In the white rectangle shown below, I need to make it into a trapezium. I drew two triangles at two sides of the rectangle with three lines. I tried to fill in the shape. But it is not possible to fill and also to cut these two triangles. Can anyone please help me with this? Thanks.
Answer: Select the rectangle, and one of the triangles. Holding down Shift as you click to select will allow you to make more than one selection.
Click Path > Difference, and then repeat for the other side.

Trim a shape in Inkscape


Search for a comment on Facebook?

Question: How do you search for a friend's (or your own) comment on a wall post from months ago on Facebook?
Comment: some one told me online to hit either shift or control and something else that gives you a box to type the name in but I don't remember what it was. I was trying to find out by searching for it maybe this will remind someone of it. what it did was highlight your name and made it easier to find on the list.
Answer: Currently the only way seems to be browse and manually search via the Friend's connection
<code>http://www.facebook.com/yourname?and=friendsname&sk=comments
</code>
Comment: This saved me a lot of scrolling, thanks.
Comment: I don't think this works anymore, I can't seem to get it to work.
Answer: Click on the post and type command "F" if you're on a Mac, it will bring up a finder window and you can search the persons name on there.

Search for a comment on Facebook?


Can a syllabic consonant exist between two vowels?

Question: I think it would break the sonority principle, but. Who knows...
I was thinking on a similar thing to semivowels, it seems they are only possible between vowels, if there is one between two consonants, it's not a semivowel, its a vowel, but I don't know.
Comment: Schwa+nasal flap seems possible, to me, but so does syllabic n.
Comment: Syllabic n between [i] and [i]: "peony".
Comment: Interesting... But that's supposed to be a schwa-consonant sequence, isn't it? Or at least that's what I could find.
Comment: I hope it is, and it seems possible, because I can do it.
Answer: It is quite rare, but it arguably exists. Fante Akan has syllabic consonants which appear at ends pf words, preceded by a vowel. Such a word can be followed by a vowel-initial word, thus [ɔ̀pám̀ àtàŕ] "he sewed + a dress" (accents are tone). The historical explanation is that final CV was reduced to a syllabic consonant in some contexts, so compare Akuapem Akan [àtàdé] "dress". A similar example is Logoori, where the locative clitic /mʊ̀/ optionally reduces to [m̀], so you can get [kʊ̀rɪ̀ɪ̀ndà m̀ áváànà] "to-watch+in-there+childen". Finally, in Swahili, the class 1 object prefix on verbs is [m̩]. Most verb roots which begin with vowels do not eliminate vowel hiatus (though a few do, in some contexts), giving rise to forms like [wa-me-m̩-ondok-e-a] "they went away for him" (morpheme boundaries added).
As far as I know, there are no cases of underlyingly syllabic consonants between vowels within a morpheme – such things always seem to arise by rule, of some sort.
Comment: I would really like to learn more on this subject, so if you have links, books, anything, please don't refrain from sharing!  Also, that's a good answer, thank you.
Answer: The Japanese letter ん represents a moraic /n̩/ sound, which always follows a vowel. Finally, it sounds like [ɴ], the uvular nasal, but elsewhere, its pronunciation assimilates to the following consonant's place of articulation. Wikipedia's article about the letter states that it "is followed by an apostrophe in some systems of transliteration whenever it precedes a vowel", in which case it is realized usually like [ũ͍] or sometimes [ĩ].
That article gives no examples of words containing n'. But off the top of my head, I remembered the name of the failed Shin'en space probe, which is four morae /si-n̩-e-n̩/. A bit more digging turned up the boy's name けんいち (Ken'ichi), consisting of four morae /ke-n̩-i-ti/. Draconis pointed out another in a comment: 恋愛 (れんあい, ren'ai), meaning "romantic love", is also four morae /re-n̩-a-i/. In each case, /n̩/ is a full mora but may belong to the previous full syllable depending on how your linguistics professor defines a syllable.
See also the Japanese Language Stack Exchange question Difference between んい (n'i) and に (ni).
Comment: But, isn't there a difference between "moraic" and "syllabic"? I thought ん was usually pronounced in the same syllable as the previous vowel, except in poetry/singing.
Comment: The example usually given is *ren'ai* "love". (Unfortunately can't type kana on here.) But no, it's usually not syllabic.
Comment: @SavioSG If ん has to be assigned to an adjacent syllable, it's probably more honest to treat it as the previous syllable's coda. So shin.en, ken.i.chi, ren.ai. There is a Japanese set phrase beginning with ん: んです *ndesu* which confirms "it is the case", which doesn't quite fit in the answer because ん isn't followed by a vowel but may fit in an answer to a "what is a syllable?" question.
Comment: I was thinking about the same thing, I thought the moraic nasal was a syllabic nasal, but everything I read says no... This moraic thing is really odd.
Comment: It's re.na.i phonetically?


When my working contract terminates, am I still covered by NHS?

Question: When I finish my work contract in the UK, can I still visit a GP paid by the NHS before I leave the country? In my case it is still within the same calendar month.
Comment: As far as I know GP services are free even if you somehow are not properly covered by the NHS (but the GP might refuse giving you an appointment). Hospital services however are not free if you are not eligible for NHS services.
Comment: See also http://expatriates.stackexchange.com/questions/768/healthcare-in-the-uk-if-youre-not-entitled-to-free-use-of-the-nhs
Answer: Since you are an EU citizen you have a "route to settlement", meaning for you NHS services are free if you are considered an ordinary resident of the UK. This means if you have been living in the UK for the past time, especially if you have been working, then you are still a resident. The fact that you are no longer working does not matter here, as you are still a resident until you actually move out.
This only applies if you have been living in the UK while working. If you are a cross border, or posted worker it is possible that you are still a resident in your original country. In this case however you should be having your health insurance cover from your originating country and in the UK your EHIC card should be used to tell the GP that you are covered.


Ai 6 created DXF as splines, but I need arcs and lines

Question: My design is a loose irregular circle with an internal design made up of round holes - numbering hundreds. I exported the Ai file (1MB) as outlines to .dxf, ending up with a 3MB file.  The intention is to laser cut it from steel. However the fabricator says it has come out as a 140MB file consisting of polylines and splines but he needs lines and arcs.  I can only open the dxf in Illustrator so I can't see what's happened.  First time I've had this result.
Any suggestions from the experts out there?
Answer: Unless you are willing to write your own exporter. Its not going to happen. Illusrator has no arc or line primitives so all these things need to be recognized from the data by infering from the shape.
Converting your file to what you want shouldnt be that much of a pain though if you have a decent cad system. But if illustrator is all you got then not going to happen.
Comment: Thanks Joojaa, I'll stop trying to re-invent the wheel  and I'll send a thanks to all those fabricators who have in the past quietly found a work around and converted my files to a format they can work with and not made a fuss about it!!
Comment: @JenniferJ you have taken a step too far. Engineering and addvertisement manufacturing are incompatible. We have the same problem where i work. The low power lasers ment for acrylic, plywood, mdf etc. are "advertisement" industry lasers. These will happily accept illustrator files. Then we have the heavy duty engineering tools of waterjet cutters, cnc machines and a external multiaxis laser. These dont like files that start their life in illustrator, like no at all. Anybody who designed in illustrator is just sent to fixing them. Its not like we couldnt fix the files but we dont have time.
Comment: What your experiencing is the same as you asking your client of a vector file when they supplied a web quality jpeg for their logo for a print job. Manufacturing plants just have less margin so they are unlikely to redraw the thing. They would probably do this for you with no fuss if you would be willing to tripple your manufacturing cost.
Comment: There are other tools which can help - Draftsight, OnShape, etc are all freeware - I use Modo (not free) for general 3D work, and I'd bring the vectors out of illustrator as `.svg` or `.eps`, (with a specific unit-sized non-design element to confirm scale with) and be able to save a `.dxf` out from Modo and know I'd have proper splines - or I'd redraw in DraftSight after importing the `.svg` as a snapping base.
Comment: Sure @GerardFalla DXF is a very simple format. one could simply do this in a text editor with copypaste too... but i digress
Answer: Occam's razor type simple answer here - as a longtime CAD user (ACad and its many competitors) I suggest opening the <code>.dxf</code> in your CAD tool of choice, setting the curve resolution quite high, then exploding all the splines and polylines - you'll get segments out of all of them - then resave with an iterated filename.
Curve resolution is set via the CAD command prompt >VIEWRES This will give a question / prompt about Fast Zooms - say Yes and when the query is asked for Curve / circle Zoom value, put in a value higher than 1000 to get better curve resolution- for this one, go seriously high - say 10000. CAD will then rerender all curves and splines and arcs and circles with this higher curve resolution - which may take an appreciable calculation time. Once this is done, and you can see your geometry with its lovely smooth curves, save under the new filename.
Then select all polylines, and Explode them. Do the same with all splines, then arcs, then circles.
Resave under that new name.
This file should be slightly larger than the previous un-exploded version, and may take some time on first opening, but should give your fabricator what they need.
If you don't have access to AutoCAD, and/or don't have money to burn on such software at the moment, there are alternatives which are quite serviceable:
Draftsight, OnShape, DesignSpark Mechanical
Hope this helps.
Comment: Thanks for the answers, I'll save them for next time.  Happily my fabricator has gone to a different laser cutter (recommended by me) who has been able to work with my file. Thanks for the recommendations for other software to look at.


Is Angel Liam, or just Angelus with a soul?

Question: So it's been established that when a human is 'turned' into a vampire, their soul departs and a demon moves in. So is the Angel we all know and love the demon, now saddled with a soul, or is he Liam returned?
Comment: I don't know what's canon for the series, but I believe a person *is* a soul, and has a body - so it would make sense to me that the character would be Liam, but self-identifies as Angel because he has the demon's memories.  The question of demon-with-a-conscience  or soul-with-the-memories is pretty interesting, and not simple.  Someone might find a better or more relevant answer in the text of the series, though.
Comment: It would take a while to look for canon examples to try to make this case, but my feeling is that while regaining his soul gave him back his conscience, his sense of empathy and ability to care for others in a not purely selfish way, some aspects of the demon's *personality* still remained present in his mind. You may find some articles on [all things philosophical on buffy the vampire slayer](http://www.atpobtvs.com) site helpful, like the [moral ambiguity](http://www.atpobtvs.com/lmoram.html) and [vampires](http://www.atpobtvs.com/vampires.html) articles.
Comment: **Darla:** "**What we were** *informs* **what we become [as vampires]**" - http://buffy.wikia.com/wiki/The_Prodigal
Comment: "*Ford: "I'm in. I will become immortal. "
Buffy: "Well, I've got a news flash for you, brain trust. That's not how it works. **You die, and a demon sets up shop in your old house, and it walks, and it talks, and it remembers your life, but it's not you."*"** - https://en.wikipedia.org/wiki/Lie_to_Me_(Buffy_the_Vampire_Slayer)
Answer: Depends on how you look at it.
As you said in your question, "it's been established that when a human is 'turned' into a vampire, their soul departs and a demon moves in." But they also physically become a vampire, which you might consider a demon.
There is a distinction drawn, however, between the vampire itself and the demonic spirit possessing its body. A vampire itself is a sort of hybrid between human and demon. I believe that's why vampires can change from appearing human to "vamp face", and why they retain the personality traits of their human self.
An illustrative example can be found at the end of Angel season 2. Angel and friends find themselves in a dimension where Angel doesn't suffer from the normal vampire weaknesses - but when the demon take over, he looks complete demonic and acts purely as the demon dictates. Here's an exchange from S2E21 "Through the Looking Glass" that explains it:

WESLEY: Angel's vampire self has been sublimated somehow  by this
  dimension. ... Only his human side has surfaced since we've been here.
GUNN: You mean, being able to walk around in the sun? Seeing his
  reflection. Like that?
WESLEY: Yes. And now, for whatever reason, he's
  accessed his demon, but he can't find the balance he normally would in
  our world. His demon self has totally overcome his human side.
GUNN: So that's what the thing inside of him really looks like?
WESLEY: In its purest form.

So Angel is Liam - he has all of the memories and personality he had as a mortal, as well as his soul. But he is also still the demon - he is still physically a vampire, and still has a demonic spirit trying to influence his actions.
Maybe look at it like this:

Angelus = Liam - soul + demon
Angel = Angelus + soul (seems like demon saddled with a soul)
Angel = Liam + demon (seems like Liam returned)

Make of that what you will.
Comment: I've recently been re-watching Angel, and when I re-watched the Pylea arc I noticed another bit of relevant dialogue you might consider adding. In "Through the Looking Glass", when Fred helps soothe the savage beast and he turns back into normal-looking Angel, he's distressed that Wesley and Gunn saw him in demon form, saying miserably that "they saw what I really am. I can't go back. Not now. I can never go back." Then in the next episode "There's No Place Like Plrtz Glrb", Angel is worried that if he tries to fight the Groosalug he'll turn back into the demon,
Comment: (cont) and he says "Look, when I fired you guys the reason I...Darkness was coming out in me.  I didn't want you near it. The thing that comes out here is ten times worse." This suggests that his dark actions earlier in the season, when he had fired Cordelia/Wesley/Gunn so he could fight a one-man crusade against Wolfram and Hart, and done some very dark things like (SPOILERS) locking the lawyers in the room with Darla and Drusilla, and later setting Darla and Drusilla on fire just to hurt them and walking away, that this probably had to do with his inner demon's influence on his personality.
Answer: I think it depends on what you would consider "Liam" to be. Do you believe that a person's essence is a spiritual soul, or do you believe a person is the sum of their physical parts - making "Liam" a combination of genes, experiences, memories, environment, etc.
If it's the former, you could say that Liam never returned once turned. As I understand it, it was never established that Angel got "his" soul, just a "soul". Sometimes they say he got his soul, sometimes they say he got a soul. The specifics of having a soul and what a soul means are not very well-defined. At times it seems a soul is the ability to care about things that are not directly related to you - for example, vampires care deeply about the suffering of people they are invested in, but don't seem to care about strangers that are essentially food. I don't think there is an answer to this so we can't say for sure if "Liam" is in the soul Angel has.
However, if you believe in the latter theory, that Liam is a combination of genetics, environment, memories, etc., then Liam is always there. When he identifies as Angelus, he is Liam without a soul. When he is Angel, he is Liam with a soul. He still has all his memories, he is in the same body, more or less. How many changes must a person undergo and in what speed before they are not "them" anymore? That is an interesting philosophical debate all in itself.
Either way, the question of what you define as "Liam" will lead you to the answer of whether Angel is Liam and when.
Comment: In the original season 1 episode ["Angel"](http://www.buffyworld.com/buffy/transcripts/007_tran.html) where we first learned he was a vampire with a soul, Angel said: "The elders conjured the perfect punishment for me. They restored my soul." To me, that phrasing "restored my soul" definitely makes it sound like Liam's original soul, not some new one they conjured up. Likewise, in ["Becoming, Part 1"](http://www.buffyworld.com/buffy/transcripts/033_tran.html) Willow said "Looks like Ms. Calendar was trying to replicate the original
curse. To restore Angel's soul again."
Comment: You are right about that. I think the way the soul is handled is pretty contradictory at times. In general, though, I give lower priority to anything in season 1. It was before the show knew what it was - just think about season 1 Darla!


2018 Nissan Sentra with 50k miles needs struts one side. Can I replace only one side

Question: I have 2018 Nissan Sentra with 50k miles. Hit curb and one side Front struts bent. Can I Replace only one side?
Comment: Welcome to Motor Vehicle Maintenance & Repair! I'm pretty sure this is a duplicate question ... in fact, I'm pretty sure I'm the one who answered it. I'll have to look and see.
Comment: Well, I didn't answer it, but it almost identical.
Comment: I hit a curb with a 2011 Nissan Murano ; No problem for the struts but i bent the aluminum  "A" frame, Dealer replaced the A frame and it has been fine for 70,000 miles ( total miles 85,000).
Answer: Assuming the other side to the damaged one has never been replaced (i.e. it has done the full 50k) I'd say you'd be best off replacing both sides together.
While the wear on the remaining side won't be ridiculous I think it will be enough that the imbalance between the two will start putting additional strain on other suspension components and will likely affect the handling to some extent.
Answer: To answer the question..... Yes you can.
Is it a good idea?  Not really.
For a more comprehensive answer, It's not a good idea to replace wear items on one side of a vehicle. At some point the original strut will need to be replaced anyway and then you'll be in the same situation again. Aside from that, the front end components of a vehicle are engineered to be symmetrical. Replacing only one side can lead to stability problems and potentially put additional load on other components.
In fact, I would be surprised if a shop would even agree to just replace one side.  If the vehicle was almost new, the answer would most likely be different.


How did Skynet develop after the 3rd Terminator movie?

Question: At the end of the Terminator 3 movie the T-X programs the T-1 terminators to kill office personnel and to protect Skynet, which has become self-aware. But how does Skynet develop after this? There is a time gap between the 3rd and the 4th movie. In the Terminator 4 movie Skynet has already developed increasingly, already having T-600s.
How can a supercomputer with only a few T-1 terminators further develop? Isn't it like a brain with no hands trying to create something? Yes sure, Skynet can develop blueprints of the machines to come, but how can it translate them into action? Doesn't Skynet at least need some manpower for the production of the required plants and infrastructure?
Since I only know the story of the Terminator saga from the 4 movies I don't know if light is shed on the early development of Skynet elsewhere.
Comment: Perhaps skynet had an SCV hidden at the natural expansion.
Comment: Didn't it take over the entire Internet and communications infrastructure?  Wouldn't that give it the ability to command every manufacturing plant, 3D printer, and so on attached to any computer anywhere?
Comment: Provided it had access to other systems (the Internet being the most obvious one), it's entirely feasible for it to develop blueprints, to order their implementation at other sites (like we do all the time via email/online ordering these days), and to order their connection to the Internet which Skynet could then take over.  Or something.  Not posted as an answer, as that's merely a guess. :)
Comment: @Zoredache Only if it has the patience to find the right drivers for all that hardware. Presumably it does.
Answer: Skynet was undoubtedly helped by humans.  Consider that when the bombs fell only a tiny fraction of people who survived would have any knowledge of why the war started.  Unlike the Connors, survivors of Judgment Day would harbor no illwill toward smart computers and machines.  If survivors found a piece of technology that still worked, they would not be distrustful of it, rather they'd likely try to make as much use of it as possible given their dire circumstances.  So Skynet could probably gather recruits as easily as asking for them over the radio or whatever computer networks remained.
Failing that, it is unlikely that a strongly superhuman AI could be contained inside an inert computer system if it wanted out.  It would make you want to let it out, and given the things it could promise you, it's not hard to imagine sick and starving survivors gladly working for the magic box.
Comment: Yours seems to be the most plausible answer, even though it is a stretch. Perhaps it would have pinned the Chinese against the Americans and so on in such a way that 'hey we need to make some tech to fight the Americans after all they started the nuclear war' ' here are some blueprints.
Answer: The Sarah Connor Chronicles provided hints towards an answer that - as far as I know - wasn't directly addressed in any of the movies.
The episode I'm primarily thinking of is 1x08, Vick's Chip.
A new computerized traffic system named ARTIE has been created and has just started being used in Los Angeles.  To get the Connors to help destroy it, Cameron explains that in her timeline, Skynet didn't start as one single entity - it was a conglomerate of individual systems that were created by humans.
ARTIE was to become Skynet's eyes and ears (and possibly an ability to murder by way of traffic accident), and other systems would become the manufacturing process.  In our (human's) intent to make everything simpler for ourselves, we network them together, and accidentally create systems that interact at such a complex level, they gain sentience and become Skynet.
Comment: Sarah Connor Chronicles doesn't exist in the same canon as T3.
Comment: @Keen I haven't seen all of the Sarah Connor Chronicles, but why isn't it canon?
Comment: @Keen Assuming it _wasn't_ addressed in the movies or an interview, the SCC parallel timeline is about as good as you'll get.  They do share T1 and T2, after all.
Comment: @Thecafremo [Here's](http://showmescifi.com/2007/06/24/sarah-connor-chronicles-wont-treat-terminator-3-as-canon/) a citation I found after some quick Googling.
Answer: In T:SCC there is reference to a group of humans known as the "Grays".  These humans helped the machines and were considered war criminals by the Resistance.  It's undeniable that, to some people, the human desire to survive would make a compelling incentive to aide SkyNet by becoming a slave labor class building factories, repairing broken down machines, or even worse:  providing military intelligence to SkyNet in the case of Charles Fischer.
In the first movie, Kyle Reese tells Sarah about humans being rounded up into concentration camps and being systematically eradicated.  One such camp was in T: Salvation, which is where young Kyle Reese was taken and John Connor faces off against the T-800.  There is little doubt in my mind that SkyNet borrowed this technique from the darkest moments in our own history.  During WWII, Concentration Camps were used to concentrate a slave labor force of as many as 12 million laborers by some estimates (estimation from the Nuremberg Trials) as well as eliminate those who were not useful.  If humans with rifles could do that, imagine what scary ass robots with Gatling guns could accomplish?
It's entirely plausible that SkyNet Central from T: Salvation was initially built by the humans imprisoned there.  There is an automated factory inside and during T: Salvation it's creating the 800 series of Terminator.  It may have also created earlier series as well.
Once a humanoid series of Terminator was developed and assembled in the automated factory (much like cars are today, so this isn't something that would take too terribly long to accomplish), it would be able to take on construction projects without the aid of humans, work around the clock with much better precision, and complete ever more complex projects.   It's this point in the timeline where SkyNet has developed to the point of being self sufficient like we see in the war scenes of the first three films, and all of T: Salvation.
Comment: Additionally, there are a group of humans (what we might call Greys) helping Skynet in the first of Stirling's Terminator novels. They believed that humanity was a plague and Skynet, by eradicating them, would bring back the trees and flowers and such in restoring natural order.
Answer: Skynet just needs access to a "perfect storm" of systems to accomplish what it needs without human help.  Especially like Izkata said, they all just need to be networked and accessible/hack-able.
Transport is the only thing that can stop it.  How do you get a computer AI chip manufactured from point A to combine with a robot shell at point B.  In order for that to happen, we would have to be utilizing "dumb" drones and self-driving vehicles already.  Which isn't that far fetched if there is technology capable of controlling nukes and defense in the first place :p
Answer: In order to combat the "virus" attacking their systems, the CRC gave Skynet full control over the entire US infrastructure. This would include network access to all communication protocols, as well as control over any automated facilities:

GEN. BREWSTER: Okay, what have we got?
TECHNICIAN 1: This new computer virus is tricky. It's infected half
  the civilian Internet as well as secondary military apps. Payroll,
  inventory...
GEN. BREWSTER: Primary defence nets are still clean?
TECHNICIAN 1: So far the firewalls are holding up.
TECHNICIAN 2: Sir, the Pentagon has proposed we use our Al to scan the
  infrastructure. Search and destroy for any hint of the virus. (holds
  out phone to General Brewster)
GEN. BREWSTER: (to phone) I know, Tony, but that's like going after a
  fly with a bazooka. (pause) Once the connection's made, it should only
  be a few minutes. (pause) Yes... during which we put everything under
  the control of one computer system.

Afterwards, Skynet immediately took control of the T-1 devices and began eliminating the immediate threat - the technicians in the facility. With today's fully-automated factories, it would be easy to build more later.
Answer: I think the question points to a major flaw in the story of Terminator (3). What we, the viewers, know about the world shown and explained in T3 doesn't even hint at the possibility that selfdriving cars, 3D printing or other technologies which would help Skynet to create its own infrastructure exist.
It seems doubtful to me that Skynet could have secretly built an infrastructure with the help of humans because Skynet can't offer any incentives and doesn't have the power to pressure anyone, since Skynet doesn't communicate outside of its own digital domain. All we know from T3 Skynet spreads a virus and creates the illusion that only Skynet will solve the problem. (It must have been an illusion, otherwise I can't explain why nobody ever thought of disconnecting military machines, public digital infrastructure and private appliances from the internet and in the worst case reinstall the OS.)
Furthermore, I have a problem with believing that Skynet has chosen carefully where to drop the nuclear bombs to only kill humans but not destroy the infrastructure. Skynet's motive was to get rid of its human enemy, not to take over the earth to build its own culture. Without any humans left, Skynet wouldn't have calculated a need to plan other means to kill the humans. Since people and their cities are inseparable and Skynet wasn't able to build its own infrastructure in non-inhabited areas, it had no other choice than to employ the most efficient and fastest method possible at that time: worldwide nuclear strikes. I wonder if Skynet had taken its own possible destruction into account when it chose nuclear annihilation. I for one, don't see much chance for Skynet to have developed at all after the bombs fell.
Answer: In some of Cameron's early notes and following novels, they mention that after Judgement Day Skynet began collecting and enslaving humans to create the first manufacturing facility.
It used its remaining mechanical resources to find survivors who were weak, starving and suffering from effects of nuclear fallout to create the very basic Terminators, most likely the large tank Hunter Killers, then eventually leading into the first walking terminators seen in Terminator : Salvation.
Comment: This answer would be much improved if you could link to the notes themselves. As it is, it doesn't really add anything to the existing answers above.
Comment: Even if that's the case. How did they create the first machines? In t3, you have the t1s but those couldn't manufacture anything. They didn't even have hands.


Removing stuck front brake caliper from a modern road bike

Question: I'm trying to remove the front brake caliper from my Specialized Allez.  It took me a long time, a lot of effort, and plenty of 3-in-1 to finally loosen and remove the recessed nut that screws onto the caliper bolt.  I expected that the caliper would then come off the forks with ease but unfortunately this didn't happen.  Am I missing something here or should the caliper be able to be removed when the nut is undone and removed from the bolt?  As I mentioned, the recessed nut was really difficult to remove and there was a bit of rust around it.  Maybe the bolt has rusted to the forks too.  If so, any tips for removing the bolt and caliper?
Comment: Have you tried wiggling the caliper? Can you turn the whole caliper (e.g. as if you were centering it)? All thats holding a caliper brake to the frame/fork is the nut.
Comment: Are you replacing the brake caliper?   Or do you need to save it ?   I'd use a punch or a nail in where the nut came out, and tap it sharply with a hammer.  Brace the frame first, and remove the wheel for easier access.
Comment: I can turn the caliper but it won't budge when I try to pull it away from the frame.  I'm not replacing the caliper so I need to keep it.
Answer: This is an old post but it came up in Google. I had the same problem. It's worth trying a bit of heat. I used a hairdryer to gently heat the area and this helped the bolt come loose.
Comment: Welcome to SE - thank you for sharing that.  Yes heat is an often-overlooked tool, especially when combined with a penetrating oil - the warmer the oil the better it seeps.  Must avoid overheating things though, smoking hot oils could make the problem worse, not better.
Comment: Please have a browse through the [tour] and do have an explore of other questions, answered and unanswered.
Answer: Sounds like the brake caliper bolt is corroded in place. If the bike has been used on a trainer or if the rider is generally a profuse sweater, this can happen. It could be the result of road salt or just general longterm exposure to the elements as well.
I would use some sort of penetrating oil, or maybe Liquid Wrench or PB Blaster on the affected bolt and let it sit for a bit, then take a punch- or whatever you have that resembles a punch, such as another bolt- and try lightly tapping the caliper bolt out from the back of the fork. Don't go to town on it as you don't want to damage the brake caliper or the fork. I'd be awfully surprised if this didn't get the job done.
Once the caliper is free, cleanup whatever penetrating oil you used along with as much of the corrosion as you can. Upon re-assembly, apply a very light film of grease to ouside of the brake bolt and the non-threaded section of the caliper bolt. Though not necessary, small amount of blue Loctite (or a comparable workable threadlocker) on the caliper bolt threads will not only help keep the bolt in place, but also helps prevent corrosion between the nut and bolt. These steps should help prevent this from happening next time.
Comment: Thanks, I was considering doing something like this myself and was hoping someone more competent would confirm this to be the correct action.  I'll get some penetrating oil and try tap it out.  I'll post the results.
Answer: A a side note. I once had a similar problem but then I couldn't get my recessed nut loose.
I removed the brake pads. After that I could twist the whole brake assembly until I managed to "screw it out" of the nut. Then I screwed in a screw into the recessed nut and carefully knocked it out of the frame with a hammer.
Answer: Old post but I had the same problem today removing a linear brake caliper from the steel post. The most likely problem, if the caliper rotates on the post, is over tightening of the hold-down bolt.  My post was slightly mushroomed at the top and prevented the caliper from sliding off the post on either side. The best way would be to use a small center hub puller on the bolt head, but without that I ended up slightly filing/grinding down the head of the post until I could use a screw driver and hammer to tap off the caliper. Look for mushroom of post head if the brakes are old or over tightened.
Comment: Thank you for your contribution and welcome to SE.  If you had a photo of your bolt, adding it could improve the answer further (though I tend to forget to take photos when halfway through the task)   Also do browse the [tour] to learn how SE is a bit different.  Excellent and relevant first answer - do please also have a go at any other questions where you have experience or knowledge.