Did Jesus condemn contraception

Question: Are there any passages in the New Testament where Jesus himself condemns the practice of contraception? As a virgin and the product of a miraculous conception himself it would seem odd for Him to have a strong opinion on the subject.
Comment: Welcome to Christianity—Stack Exchange pguardiario!  @David: You are correct.  My entry answers the question fairly well, I think.  In sum, the Bible has no mention of contraception with the possible exception of an [obscure](http://hermeneutics.stackexchange.com/q/1239/68) reference to what the Talmud calls "thresh[ing] within and winnow[ing] without".
Comment: If you're wondering about the various Christian views on contraception, check out the blog entries: http://christianity.blogoverflow.com/?blt=1  There are two entries out there already, and if I'm not mistaken, two more to come?
Answer: No, there are no passages in the New Testament where Jesus even speaks about contraception.  Coincidentally, He never mention airplanes, computers, fast food, or cell phones either.  :)
All of these are modern inventions for which there was no vocabulary or context in which teaching could be given.  (While there were examples of contraceptives in ancient history, the Jewish people don't appear to have used any.)  The basis of the teachings of the Catholic church and others comes from arguments of design.  God's design of intercourse leads to reproduction--not all the time, of course, but that is certainly a reasonably common outcome.  Additionally, there is a specific command given to Adam and Noah to fill the earth and multiply upon it, so taking unnatural action to prevent reproduction seems to go against that to some extent.
Also, the idea that Jesus would not have a strong opinion on the subject, merely because He Himself was the product of a miraculous conception, ignores the Biblical teaching that Jesus was Himself the eternal Son of God who took on flesh 2,000 years ago.  The Son of God, through whom all things were created, certainly has a strong opinion on truth and morality.
Comment: [Not all contraceptives are modern inventions](http://en.wikipedia.org/wiki/Birth_control#Early_history).
Comment: @pguardiario Yes, but have you been to Wyoming? :)
Comment: Thanks for the reply @narnian. Where I live it sometimes feels that the command to fill the earth has been accomplished too well.
Comment: Intentional contraception generally also requires rejection of the Scriptural principle that children are a blessing from the Lord, instead viewing them as a burden.
Comment: There's also the line Jesus says (mark 10:8): "and the two will become one flesh.' So they are no longer two, but one." To me, this passage seems to support the catholic doctrine:
the point of contraception is to stop 'the two' from making a little 'one,' wouldn't contraception be against the will of God?
Answer: There are not any references to contraception in the Bible. The two arguments I have heard against using contraception are Onan dying after spilling his semen on the ground to avoid getting his brother's wife pregnant (Genesis 38:8-10). The other is just that it is unnatural
Comment: For more on the Onan connection, see the question: http://christianity.stackexchange.com/questions/5316/was-onan-really-struck-dead-by-god-for-masturbating Peter Turner's answer in particular has a really good insight in regards to contraception
Answer: Jesus didn't condem Contraception per se, but there is a stong traditon running back to Genesis, that children are a good thing:

Genesis 1:28 And God blessed them, saying: Increase and multiply, and
  fill the earth, and subdue it, and rule over the fishes of the sea,
  and the fowls of the air, and all living creatures that move upon the
  earth

And another (Psalm 127:5):

Blessed is the man that hath filled the desire with them; he shall not
  be confounded when he shall speak to his enemies in the gate.
Answer: If you'll excuse what may be faulty parallelism, you might see that one of the more ancient prophecies about Christ is right next to the denouncement of "those who engage in witchcraft"

Deuteronomy 18:9-15 (NIV)
9  When you enter the land the LORD your God is giving you, do not learn to imitate the detestable ways of the nations there. 10  Let no one be found among you who sacrifices their son or daughter in the fire, who practices divination or sorcery, interprets omens, engages in witchcraft, 11  or casts spells, or who is a medium or spiritist or who consults the dead. 12  Anyone who does these things is detestable to the LORD; because of these same detestable practices the LORD your God will drive out those nations before you. 13  You must be blameless before the LORD your God.  14  The nations you will dispossess listen to those who practice sorcery or divination. But as for you, the LORD your God has not permitted you to do so. 15  The LORD your God will raise up for you a prophet like me from among you, from your fellow Israelites. You must listen to him.

I don't know if no one thinks about contraception as witchcraft nowadays, but in days of yore, I'd imagine, if you'd want to get a contraceptive back in the day, you didn't go to Planned Parenthood.  You went to the old hag who knew how to conjure that kind of stuff.

I should note, witchcraft as contraception is not completely bogus opinion.
Comment: One also notes Galatians 5:20, in which the word translated "witchcraft" is the root for pharmacology, and certainly included contraceptive herbs.

Did Jesus condemn contraception


SD card cannot be mounted as /storage/sdcard0

Question: My problem is, that my Vodafone Smart Prime 6 (VF-895N) with Android 5.0.2 mounts external sd-cards as /storage/sdcard1.
On other devices with "settings" - "storage" there is a menu to change the default write disk.
This menu is missing on this device.
Is there any possibility to mount my external sd-card as /storage/sdcard0 and the internal storage as /storage/sdcard1 without rooting?
Answer: The internal storage is present as 'storage/emulated/0'. There is no way you can "load" the internal storage as 'storage/sdcard0' or anything else. Internal storage is always present as 'storage/emulated/0', you cannot change it.
Even with rooting I think you cannot reload the internal storage as sd card. Default storage location cannot be set like that. If your phone doesn't have that option, it's a pity and I believe there are apps which allow you to do so (caution: I haven't checked any).


Asking for someone to accept your answer

Question: Is it improper etiquette to, as long as you're certain, add a comment merely suggesting that they accept the answer? Do I sound like a reputation whore?
Comment: Related: http://meta.stackexchange.com/questions/109773/what-happens-if-you-answered-a-question-questioner-says-thanks-but-didnt-acce
Comment: Not really a duplicate, because the question there is only about new users. As a non-new user, I just got asked to accept an answer, for an question where I believe an even better answer is possible.
Answer: If the question was asked by a new user, and they commented something like "thanks, that worked!", then I would say that a polite comment asking them to accept would be, well, acceptable.
There is a thin line between being helpful to new users and being inappropriately demanding. So tread lightly.
Comment: I sometimes find myself leaving a comment to the new user "Thanks" comment something to the effect of "_Happy to help, and welcome to Stack Overflow. If this answer or any other one solved your issue, please mark it as accepted._"
Comment: @MichaelBerkowski Copying this shamelessly.
Comment: You have to be very careful indeed. Hans Passant made a comment that some people interpreted as a demand for an accept, and it hit the front page of reddit and got downvoted to -70.
Comment: The moral being take time and care crafting your messages to be interpreted positively and not like some over zealous uncaring SO curmudgeon. And the inverse, people will appreciate kindness.
Answer: I wrestle with this as well.  What I have worked out as a habit is:

I try to leave comments where another user has correctly answered but not yet received the green check mark.  Do unto others and all that.
For my own posts, I will sometimes comment something to the effect of, "Hi, I see you're new to SO.  If you feel an answer solved the problem, please mark it as 'accepted' by clicking the green check mark.  This helps keep the focus on older SO which still don't have answers."
To avoid undue pressure to choose my answer, this comment gets left not on my own answer but on the question.

This only applies to situations where:

It is a new user who is not likely to know how to use SO yet, and
They have made it perfectly clear that their problem has been solved.  E.g. a comment saying, "That did it, thanks a bajillion!!!!"

I feel like this solution both educates, welcomes to the community, and doesn't beg for rep.  I also try to keep a mental state that the 15 points just don't matter, and frankly, in percentage terms they just don't anymore.  E.g. I try not to actually beg for rep, not just to seem like I'm not begging for rep :-)
Finally, I try to wait a half hour or more after they've acknowledged it as the right answer before posting my request.  It's always possible someone swoops in with a better answer or it turns out that the solution I provided wasn't really the exact problem they needed.
Answer: It's absolutely OK to ask that an answer be accepted.  That way, people who find the question using Google can have more assurance that the answer is correct.
There is a reason the accept answer button is there...that way, we can see (in most cases) the best answer.  Voting takes care of bringing the other competing answers that are also good to the top.
Answer: Post a comment on the original post asking the user to consider accepting an answer. This will ensure that there isn't any bias involved when the OP picks an answer. Don't ask the OP to accept your answer... that's not the way it works here.
If the user is new and doesn't know how to accept an answer (or what it even means), you can always link to this image as well. :)
Answer: I also believe that it is perfectly acceptable to ask a user to accept an answer. They might not know of the conventions on Stack Overflow. And people without accounts will more easily know which answers solved the problem if they come to the site from a search engine or some other referring source.
Answer: No. Please accept this answer.
Well, as long as the answer has a good explanation value etc. I think it's acceptable. Does sound a bit reputation whorish though.
Answer: I think a better approach is to leave a comment on your own answer if you believe it should be accepted. However, in the comment I dont mention anything about how the op should or can accept my answer. I just use it as a follow up and offer additional help if needed. More than likely the answer will get accepted. If it doesn't get accepted and the op is not very engaged, oh well, move on to the next question and hope for a few up votes. There are plenty more questions that your answer can be accepted on. I kind of view this the same way I viewed tips when I was a server in college at a well known restaurant. The quickest way to a bad tip is to mention anything about a tip. Being genuinely helpful is often the best way to good tips. I think the same applies to accepted answers. People will go the little extra to accept your answer.
Comment: That's actually the reverse of how you should do it, in my opinion, as it is doing only the 'bad' part of things. You should instead post on their question suggesting, neutrally, *how* they can accept/vote, without suggesting that they accept/vote your own answer.
Comment: I disagree. Unless its a new user who doesn't know better, most people know to accept the best answer. Some just don't for whatever reason. But I generally don't have problems with accepted answers. Just my opinion
Comment: No problem with disagreeing. It happens. Cheers


How can I tell if 2 different utility functions represent the same preferences?

Question: I need to verify that $u(x,y)=x^{1/3}y^{1/3}$ represents the same preferences as $v(x,y)=x^3y^3$. Obviously these are completely different functions with different derivatives, so what am I comparing? What makes 2 utility functions represent the same preferences?
Comment: @VCG Why are you hating on non-continuous monotonically increasing transformations bro?
Comment: If you can find a monotonically increasing continuous transformation that turns one into the other, then they have the same preferences. Can you find that?
Comment: @denesp Oh jeez ya oops. No idea why I wrote that. Too late to edit. Oh I guess I was thinking of needing the utility function to be continuous for sufficiency.
Answer: Recall the definition:

The function $u: X \rightarrow \mathbb{R}$ represents $\succeq$ on $X$ if for any $x,y \in X$, then $x \succeq y \iff u(x) \geq u(y)$

We can show that if $u: X \rightarrow \mathbb{R}$ represents $\succeq$ on $X$, then for any strictly increasing function, $f: \mathbb{R} \rightarrow \mathbb{R}$,  the function $v(x) = f(u(x))$ also represents $\succeq$
(Short) Proof: For any $x,y \in X$, if $u$ represents $\succeq$, then $x \succeq y \iff u(x) \geq u(y)$ by definition.
Because $v$ is strictly increasing, $f(u(x)) \geq f(u(y)), \implies v(x) \geq v(y)$.
Thus $x \succeq y \iff v(x) \geq v(y), \implies v$ represents $\succeq$

In your case, you have $u(x,y) = x^\frac{1}{3}y^\frac{1}{3}$, and can set $v(x, y) = (u(x,y))^9 = x^3y^3$, your desired result.
Answer: Another trick is to compare their marginal rate of substitution. If for a similar marginal rate of technical substitution (i.e. relative prices) they yield the same relative inputs, then they represent the same preferences (basically one is a monotonic transformation of the other; see below).
For the first preferences you give, this is:
$$ \frac{\dfrac{\partial u}{\partial x}}{\dfrac{\partial u}{\partial y}} = \frac{y}{x} $$
It is trivial to show that the second function yields the same MRS. Hence, they represent the same preferences.

Another way to look at this is to notice that optimising a function $f(x)$ is the same than optimising a monotonically transformation of such function. Thus, apply the natural logarithm to the two functions and you get, respectively:
$$ \ln u = \frac{1}{3}\left(\ln x + \ln y \right) $$
$$ \ln v = 3\left(\ln x + \ln y \right) $$
Notice that $\ln v = 9\ln u$. Hence, they are indeed the same.


Should :focus and :hover styles be the same or distinct?

Question: I'm in the midst of redefining a cross-application style guide, and I want to make sure we're accounting for accessibility in the design, including contrast ratios, text sizes, and focus states.  One issue that's been bugging me is whether the :focus state for buttons, inputs and the like should be the same as the mouse :hover state, or if it should be distinct so they could be layered together.  I'd love to get some reasons why they should or shouldn't be separate.
Answer: The focus state should be more obvious than the hover state
A mouse over or :hover state is a more direct interaction (i.e. the user is controlling the mouse cursor directly over the button they want to click)
The :focus state, on the other hand, requires a separate scan of the entire page in order to determine which component is currently being targeted.  For example, a user may press the TAB key a few times until a focus rectangle lands on a link, button or other input they want to access or "click" by pressing the ENTER key.  The item that currently has focus needs to be obvious so that the user knows when to stop pressing the TAB key and can confidently interact with the focused target.  It is common to place some sort of rectangle around a focused button that is easy for the user to spot.
In the case of a hover event the mouse cursor itself fills this role so a focus rectangle isn't required.
Below is an example showing different button states in Gmail...
Comment: That tracking makes my skin crawl. Waht is "compo se"?
Answer: Honestly, as long as your :hover state & :focus state are very clearly showing exactly which item will have action the taken on it, I can't see any reason to style them separately. :focus is essentially a keyboard hover.
The previous answer is correct in saying that a :focus element should contain a box around it, but as long as the outline property isn't hidden, it shouldn't be an issue.
The only time it might be worth styling separately is if you are auto-focusing on items without the user directly interacting with them.
Comment: So in principle you seem to be saying: style them 'the same' but make sure to _also_ add an outline? Styling them 'the same' would be a bit of a contradiction, and only work in case all hover styles use an outline as well.
Comment: I agree with your idea highly as on mobiles when there is no hover then on your desktop and mobile version of website will have different button pressed state which is a bit inconsistent
Answer: All visual states can be combined in a matrix. Indeed focus needs more distinction than hover, but can also be combined when you hover over your focused element.
These states can also be combined to unselected and selected items.


Sales Tax Data for NYC

Question: Sales taxes collected (from retailers) would be a great proxy for general economic activity. Using sales tax data, you could get a rough idea of the revenues collected by retailers in a given area. Since it's tax information, my gut tells me this type of information should be available. Unfortunately, I haven't been able to locate anything like this so far (I filed a FOIL request a few months ago and never heard back). Specifically I'm interested in sales taxes in NYC, but any info on taxes collected in the US could be useful. Any ideas?
Comment: Where did you send your FOIL request? Tax revenue is collected by NY State on behalf of NYC and other localities. Unless you sent a request to the [NYS Department of Taxation and Finance](https://www.tax.ny.gov/), it's probably not going to be processed. There is also likely a privacy concern with releasing this information, though NYSDTF does list "Tax filings by individual and/or business taxpayers" as a topic on it's [FOIL Subject Matter List](https://www.tax.ny.gov/forms/dtfsml.htm)
Comment: I submitted a FOIL request to the New York Department of Taxation and Finance on 5/11/2016. On May 16th, 2016, I received a reply stating:  "we understand that you will be working with Office of Tax Policy to obtain the information you are seeking and they will be reaching out to you shortly. OPTA is best suited to meet your data requests". After that I never heard from the OPTA or NYDTF. If the government fails to follow up on a FOIL request, what options do I have?
Answer: I have not come across this data for NYC (though would also be really interested in it if the data existed publicly somewhere!), but know that you can get sales tax receipts for a few categories for the state of Texas at least.
The state of Texas publishes sales tax receipts data on the following areas:

Mixed beverage (think bar receipts)
Hotel occupancy
Franchisees

These datasets include:

Company name
Company address
Reported tax
Gross receipts

The last month's filings are available through the Texas government here and more historical data is available through Enigma.io here.
(Full disclosure: I work for Enigma.)
Answer: This question is one year old, but still: https://www.census.gov/govs/statetax/historical_data.html
isn't this what you need?

Sales Tax Data for NYC


Is there a safety issue with freezing raw chicken with raw stuffing?

Question: I was planning on making stuffed chicken capons and freezing them raw. This is with fresh raw chicken and raw stuffing (no eggs), and then freezing the chicken stuffed with stuffing and defrosting and cooking at a later point. I was told that it's a safety issue and I should instead half-cook the capons and then freeze. I don't see the logic in this and haven't been able to locate any proper source. Is there any reason why this would be unsafe?
Answer: Your method of stuffing and freezing raw should be safe. Assuming you are following safe food handling and freezing methods, you will be fine.
Just prep your chicken and get it into the freezer within the recommended window of two hours that it can safely be in the "danger zone" of 40-140 F.
As it pertains to bacteria, you can think of freezing as stopping time. You are essentially putting all those pesky microbes on pause, so they can't multiply and have a big ol' botulism party on your chicken. So if your food is clean and safe when it goes into the freezer, it should be clean and safe when it comes out.
I can't see any point to par-cooking your chicken, and as James points out, it seems to complicate the process unnecessarily.
Also check out the USDA guide on Freezing and Food Safety.
Comment: The freezer does indeed "stop time"... except with something as large as a chicken, if it goes in while it's still in the danger zone, it may take a while before the inside cools below the danger zone and time actually stops. This could be pretty relevant since the OP's stuffing is probably close to room temperature and the bird is probably cool but in the danger zone.
Comment: @Jefromi I believe OP is talking about *stuffed capons*, which are relatively small and should freeze readily, [like these](http://overtimecook.com/2012/09/26/pastrami-stuffed-chicken-capons/), for example. Not to be confused with a *capon*, which is like a rooster they seem to like in France. You are correct, though, that freezing a whole bird might pose more of a challenge.
Comment: Ohhhhhh that's fine then! And less surprising!
Answer: I don't think the problem is the freezing per-se, it's the likelihood of ending up with things not fully cooked, or of them being in the danger zone (between 40 and 140 degrees Farenheit) for too long.  If the total cumulative time in the danger zone for any part of the bird or stuffing is within 60 minutes (some people say 120 minutes, but that may include time while it's cooking), you should be fine.  When you want to cook them, you'll have to defrost them thoroughly in the refrigerator (probably for at least a day or two) and make sure when you cook them that the coldest part (usually the centermost part, but not always) is up to the recommended 165 degrees Fahrenheit.  If you were to try to cook them directly from frozen it's likely that the outside would be burned while the inside would still be cold, or you would have to cook them at such a low temperature that they would spend too long in the danger zone.  If you were to thaw them on the counter, they would certainly be in the danger zone too long (every minute at room temperature is a minute in the danger zone).
I think half-cooking them would only increase the likelihood of safety issues due to multiple warming/cooling cycles.
Of course, as with most food safety issues, there's a good chance you will be fine anyway, but no reputable professional would risk going outside the FDA guidelines without a good reason and probably a warning to the consumer as well.
The FDA provides online Food Safety Information describing the risks.  You can also call them with questions.
Answer: Fresh poultry is generally kept at "safe" chilled (below 40f), but not frozen temps for extended periods.  Keep the chickens or Capone refrigerated until your ready to stuff the get them back in the fridge or freezer as soon as possible. You may even want to chill the stuffing before use.
The safety issues with stuffed poultry generally come when thawed and then cooked-reheated.  The meat and stuffing may thaw at different rates. If they are not completely thawed in the fridge, you run into the issue of either the bird must be left at room temp too long or a very long defrost time. If the chicken or capon is cooked frozen or still partially frozen. You'll get uneven cooking. By the time the stuffing hits 165 f the bird will be dry.


Export all data for Contact

Question: i'm new on civicrm and try to export specific contacts. I found the search menu to select the data and i made an export with " Export PRIMARY contact fields" but some fields are not in the export. How i could select all the fields of my contacts create on the civicrm database. Thanks for your Help. Marilyn
Answer: Welcome to stack exchange. There are some other questions that may provide you with some answers. Before asking a question you should always do a search. Try searching for "export all data". Also it would be worth saying why you want to do this export. It seems an odd thing to do with a new site.
But to help you, "Export PRIMARY contact fields" is a particular set of fields chosen by someone else and rather general. If you choose "select fields for export, you can chose whatever you want. A bit tedious for all fields, but you can save the selection for later use.
Be aware that you can't export multi-value custom fields this way (though you can get a report to do this.
Comment: In addition to Mick's answer you should be aware that contribution, membership and event data is not part of the contact entity. If you like to export for example contribution data you need to use a search like "find contributions" and then "export contributions".
Comment: See also the documentation on exporting contacts: https://docs.civicrm.org/user/en/latest/common-workflows/exporting-your-contacts/

Export all data for Contact


Why is human vision restricted to 400-700 nm?

Question: Across the electromagnetic spectrum, 400-700 nm is a narrow spectrum of frequencies and focused in the region of short wavelengths. For example, radio waves cover a large range of frequencies unexploited by the visual system. So what biological reason is there that evolved us to use such a small frequency bandwidth for vision?
Comment: We can only answer "how" or "how come"? "Why" actually is quite speculative and philosophical. Why human are the way they are? Why didn't humans evolve to swim naturally or run fast (very favourable attributes)? We can just guess the "why". :)
Answer: Short answer
The visible spectrum has the highest energy in sunlight at the earth's surface, explaining the gross location of the visible spectrum in life on earth. The specific frequency range varies across species and can be explained by species-specific survival strategies.
Background
When you look at the solar light spectrum at the earth's surface the visible spectrum has the highest intensity (fig. 1).

Solar irradiation. Source: University of California.
So it makes sense to use the range of frequencies that is represented most in sunlight as a starting point.
Then the question becomes, why do humans utilize approximately 400 to 700 nm, and not infrared or UV? That can be explained because we do not need it. Our range has been hypothesized to be related to foraging behaviors and our visual system is particularly sensitive in the frequency range of the coloring of (ripe) fruits, which is thought to have been of great benefit to our hominid ancestors (Osorio & Vorobyev, 1996).
Why then do animals extend their vision into UV? Many fish, amphibian, reptilian, avian, and some mammalian species use UV vision. Many birds can identify UV-reflected nectar and berries, and UV-reflecting plumages in birds, and scales in fishes are used for recognition (Shi & Yokoyama, 2003). Moreover, some arthropod species are know to use UV vision to reduce light-reflection distortions under water, such as in the mantis shrimp that features 12 photoreceptor types (as opposed to four in humans) (Thoen et al., 2014).
Why then do animals extend their dynamic range into the infrared? A notable beneficial effect of perceiving infrared is the detection of body heat. The generation of heat is accompanied by the generation of infrared light. The detection of this emitted light is highly useful for nocturnal predators, like the rattle snake (Hartline & Newman, 1982).
References
- Hartline & Newman, Sci Am (1982); 246(3): 116-27
- Osorio & Vorobyev, Proc Roc Soc B (1996); 263(1370)
- Shi & Yokoyama, PNAS (2003); 100(142003): 8308-13
- Thoen et al., Science (2014); 343(6169): 411-3
Further Reading
1. Is our color vision calibrated to sky, vegetation, and blood?
2. Is there a physical reason for colors to be located in a very narrow band of the EM spectrum?
Comment: Not that you said it was, but I'm not sure if snakes detecting IR light can be classified as vision. Anyways, nice answer +1
Comment: @canadianer - I classify *vision* as *light perception*. People classified as having *ultra-low **vision*** (near-blindness) sometimes have not much more than bare light perception (light on or off).
Comment: It's largely a semantics issue I think and I don't really know why I even brought it up ;) [A plant can perceive light](http://www.ncbi.nlm.nih.gov/m/pubmed/12972045/), thought I wouldn't say it has vision.
Comment: @canadianer - plus I never said that snakes had IR vision in my answer in the first place lol. I used *perception*
Answer: Most of the light from the sun doesn't actually reach the earth's surface due to the atmosphere.

[source]
So the light reaching earth includes near-UV, visible, near-IR and a band of radio waves. Seeing any other part of the spectrum would be impossible since it doesn't reach earth.
You asked why we only see in the visible light range; this is due to evolution. Birds, among other animals, can see UV light. In fact, all vertebrates have the potential for near-UV vision. Humans, as vertebrates, also have UV-sensitive photoreceptors. However, our lens is opaque to UV light:

[from Clinical Ocular Anatomy and Physiology via this website]
Just speculating, it would seem that the ability to see near-UV is an ancestral condition which we lost at some point; either it provided no significant advantage (neutral regression) or there was some advantage provided by a UV-opaque lens, either directly (such as protection from UVB light) or indirectly (through pleiotropic antagonism).
On the other hand, human photoreceptors cannot detect IR light. Again, this is a product of evolution.  These researchers hypothesize that the longer the wavelength of light detected, the more noise is produced. This noise is due to activation of the pigment molecule by heat. Or, it could just be that never happened. An IR-sensitive photoreceptor might be possible, but evolution doesn't lead to perfect adaptation. In other words, there isn't necessarily a reason why.
As for radio waves, they are too low energy to interact appreciably with matter, at least as far as vision is concerned.
Comment: Most photoreceptors, the way they work, cannot absorb IR because IR is too low in energy to cause electronic transitions. Regarding false alarms; yes heat can generate false alarms but that doesn't mean noisy (in fact IR scatterance is much less. Rayleigh scattering reduces with wavelength). I would reason that diurnal habit and temperate habitat of humans does makes IR sensing not very useful.
Comment: While it is true humans do have some marginal sensitively to UV (basically spillover) we have no UV focused receptors like many other animals. this is true of Mammals in general so the group as a whole seems ot have have lost UV sensitivity. A major problem with infrared is water is not very transparent to infrared, and what are eyes made of. this is why pit vipers have open air filled pits for infrared detection.
Answer: Its not really
That is only the human visible spectrum.
Humans actually have a reduced spectrum compared to many animals. Mammals in particular have a reduced spectrum compared ot non-mammals. Reptiles and birds have 4 color sensitive cell types (cones) and can see into the ultraviolet. Many invertebrates can see an even wider spectrum. Mammals lost two of these cells. Modern mammals are descended from early mammals who were nocturnal Thus color vision was less useful. Primates evolved a third cone, (a mutant variant of one of the two they had before) Primates did this because many are frugivores and color is excellent for determining when fruit is ripe.
Answer: This is my speculation, but there are no or few organic chemicals which can absorb radio waves having longer wave lengths. Eyes sense lights by absorbing light with organic chemicals, but to sense longer wave length, eyes might need more sophisticated devices like tuners.
In addition, less than 100nm radio waves from the outer space are absorbed by the atmosphere, so even if eyes could sense such radio waves, you don't see any signals on the earth.
Comment: This answer holds great potential, especially the radio wave part. Elaborating on that may get you your deserved upvotes.
Answer: "Visible light" is the wavelength of the light that we can see, if human beings could see UV or IR, those wavelengths had been included in the "visible light" definition.
Now, our Sun is brightest in yellow-green light, which (you guess?) is right in the midle of the "visible light" spectrum. So the only remaining question is: "Why can we only see that short spectrum?" The answer is EVOLUTION.
The same reason that made us to have only 5 fingers in our hands, only 2 eyes and only two kidneys.
The bandwith of the "visible spectrum" is enough to make the human beings (as specie) survive.
Comment: Every question can be answered by '*this is EVOLUTION*'. I do acknowledge the inherent problematic nature of the *why* questions, but they nevertheless form an interesting class of questions in the light of speciation. Further, the capitalization should be used with caution as it implies yelling at OP. It is a legitimate question.
Comment: it is also a bad answer using evolution, since there are some pretty solid evolutionary artifacts that make human vision very limited.
Answer: These wavelengths happen to satisfy two conditions.
First, shorter wavelength photons (EM radiation) tend to be dangerous for biology. Even UV light (<350nm) is already can damage DNA. That is due to the fact that bond energies in biological molecules tend to have values close to energy of short-wavelength EM radiation. These is why high-energy particles called ionizing radiation. For reference, see this paper. ionization energy for DNA estimated in 4-5eV range, which is 300-250nm.
Secondly, on low-energy hand of spectrum, water absorbs a lot of IR radiation:

So, as you can see, what we see aka visible spectrum is sitting nicely in valley of water absorption but does not extend to area of harsh UV light that will damage chemicals of your body.
Now, why is that so? Because atoms have these masses and electrons around them have these energies. So bonds and molecular interactions have these values.
(In radio range of frequencies you, opposite to UV, have not enough energy to elicit any significant molecular changes, which is why you can't perceive WiFi)
Comment: The reasoning that UV shouldn't be visible because it is dangerous makes no sense. Along that reasoning the visual system should be filtering out predators, guys with guns etc. as well. Moreover, there are classes of critters that sense UV and use it for meaningful purposes.
Comment: Essentially none of the UV light that reaches the surface is ionizing. Lower wavelength UVB light can damage DNA, but this is hitting our body and eye whether we can see it or not. About 95% of UV light that reaches the surface is non-damaging UVA.
Comment: Reasoning is one thing, claiming it to be so is another, especially since many species actually use UV. Oxygen is highly toxic. Should we therefore neutralize it before we breath?
Comment: @AliceD My reasoning is following: UV is dangerous hence it is/should be filtered before it reaches anything sensitive. Animals don't really need retinal cancer.


Who is experiencing the non self?

Question: There is no self that is permanent. All this results from 5 aggregates, then who is experiencing the non self?
Answer: There are several questions on this site which are more-or-less about this topic.
One which I found helpful was, How is it wrong to believe that a self exists, or that it doesn't?
I also liked this little summary of Right View, which includes, "A thicket of wrong views".
Answer: Why, of course Buddha is experiencing the non-self. Arahant is experiencing the non-self. Bodhisattva from the first Bhumi and above is experiencing the non-self.
Answer: You have this question a bit upside down and backwards. The point is that we mistakenly associate the 'self' with the five aggregates. What we think is the 'self,' isn't. It's like walking around wearing a name-tag that says 'me,' and pointing at it whenever anyone asks who we are. If someone rips off our name-tag and runs away, do we suddenly stop being 'me'? But we are so used to pointing at the name-tag, that we lose track of the distinction between it and us.
The idea of 'no self' is a way of ripping off the name-tags. It's not a question of who is there experiencing 'non self'; it's a question of who is there experiencing all the false labels of 'self'.
Comment: Is the name tag "the aggregates", is this analogy? Are you saying there is a self but that it's other than the aggregates? :-) And what's the basis of this answer, what doctrine (or personal experience) is it based on?
Comment: The various aggregates that we identify with become 'name tags'. You have awareness, therefore you have experience that is reasonably interpreted as a self. The Buddhist problematic arises when you begin to connect with various aggregates as 'permanent' features of an 'identified' self. You can't really argue with 'I am,' because 'I am' is the fundamental condition for arguing with anything. The problem enters when 'I am' becomes 'I am this' or 'I am that.'
Comment: Thank you (and I didn't mean to challenge you, I just didn't understand the answer).
Comment: Oh, no worries. I didn't think you were being challenging; nothing here to challenge except our own curiosity.
Answer: The mind experiences not-self.
Questions about "who" are irrelevant, per the Phagguna Sutta .
Answer: I can't give answer this question.  But I  will attempt this question.
We aren't going "non self "
First question " who am i "
I am "name" so I can live without "name" so  I am not "name".
Who told you aren't name?.  Answer =mind saying
You can understand....
I am "identity " identity means docter, engineer, monk, Hindu,Muslim.
So  without  identity you can live so you aren't identity..
Who told you aren't identity? Answer =mind saying.
I am physical body. In physical body many parts so we are discussed.
I am  hair  so without hair we can live so I amnot hair.
I am leg and hand  But without leg we can live so I amnot leg.
I am eye, ear , but without   eye and ear we can live  so I amnot eye and ear..
I am  mind but without  mind can live so I amnot  mind for  example  comma .
I am "breath" but without breath we can't live..
This is my last   lever. I amnot going next level.
Answer: That's exactly right.  When you find out "who" that is, you will have resolved the matter of birth and death.
Just keep asking "who?  who?  who?"  Don't put the question down for a second.  Keep it so close that no air can escape.

Who is experiencing the non self?


Breeding mosquitoes at lower temperature

Question: It is well known fact that, to slow down the growth of drosophila, they are grown at 18-19 degree Celsius. It helps in maintaining stocks for longer time without frequent change of food. Is it applicable to mosquitoes? especially Aedes aegypti?  can we slow down its growth by growing them at lower temperature?
Comment: I think there are 2 questions : temp for breeding and, temp for growing larva. I see larva dormant at about 45 F, then at 60+ F they are active.  again.
Comment: @blacksmith37 Possibly even three, as written - temp for maintaining larvae, and temp for maintaining adults. I'd suggest editing out "breeding" from the title, unless you really want to know about this, but I think effects on larvae and adults can be answered as two parts of the same question.
Answer: Check "breeding temperature" and similar obscure phrases for the search.
There's a study on physical aspect of mosquitos bred in cold, they perhaps didn't note any significant metabolism change, you can read the articles, they mostly cover wing length scales and follicles.
There's a study on lave development speed which passes over breeding temps, it may however cover "egg temperature".
Answer: Maybe:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3992806/ is a NIH paper that gives a quick overview on maintaining an A. aegypti colony.  From the description they are somewhat fussy, but some of the lines imply temperature sensitivity at least at certain stages.
try google 'protocol for maintaining mosquito colony'
Comment: Dear Sherwood, I hope u did not understand my question properly. I know the standard protocol for rearing mosquitoes. My question is whether rearing them will slow down their metabolism and thereby their growth? if so will rearing at lower temperature harm them in any way other than their growth? (like their survival, lifespan, mating behavior,egg laying behavior etc.,)
Comment: Also just wanted to comment that Aedes aegypti is widely accepted to be the *least* fussy mosquito species to care for. We have far more trouble with Culex and Anopheles than any of our Aedes.


What does "in persona Christi Capitis" mean?

Question: The Church says that the Priest acts "in persona Christi Capitis".
Where is this term taken from?
Comment: @jlaverde If you want to begin a debate over denominational practices, head to chat. Hank, where did you first hear of this, and what research have you done regarding that term?
Comment: Debate? Is this really up for debate? How do Catholics debate this?
Comment: No one is upset here, but we do need to know where you heard or read this, and if you've done any research about it already.
Comment: Hank, Catholics don't debate this.  I was trying to remind jlaverde that we don't argue about "truth questions" at this site.  please see [we cant' handle the truth](https://christianity.meta.stackexchange.com/q/3527/24204) on Meta.
Answer: It means: "in the person of Christ the Head [of the Church]".
Christ is the High Priest, in Whose person all other ordained priests act when they offer the Holy Sacrifice of the Mass.
When a Catholic priest consecrates the host and wine, he truly identifies Himself with Christ when he says "This is my body." and "This is my blood."
St. Robert Bellarmine writes (Controversiis t. 2, De Missa, 1, c. 27), as quoted in Pope Pius XII's encyclical on the sacred liturgy, Mediator Dei §86:

The sacrifice is principally offered in the person of Christ. Thus the oblation that follows the consecration is a sort of attestation that the whole Church consents in the oblation made by Christ, and offers it along with Him.
Sacrificium, inquit, in persona Christi principaliter offertur. Itaque ista oblatio, consecrationem subsequens, est quaedam testificatio, quod tota Ecclesia consentiat in oblationem a Christo factam, et simul cum illo offerat.
Comment: Didn't St Paul also use this term?
Comment: @Hank Are you referring to [2 Cor. 2:10](http://drbo.org/cgi-bin/d?b=drl&bk=54&ch=2&l=10-#x) ("…for your sakes have I done it in the person of Christ.")?
Answer: What does "in persona Christi Capitis" mean?
In persona Christi Capitis is a Latin phrase meaning "in the person of Christ the Head of the Church", an important concept in Catholicism. A priest acts in persona Christi, because he acts as in the place of Christ. The term, In persona Christi capitis, "in the person of Christ the head of the Church," was introduced in by the bishops of the Vatican Council II in the Decree on the Ministry and Live of Priests, Presbyterorum Ordinis, December 7, 1965.1

The office of priests, since it is connected with the episcopal order, also, in its own degree, shares the authority by which Christ builds up, sanctifies and rules his Body. Wherefore the priesthood, while indeed it presupposes the sacraments of Christian initiation, is conferred by that special sacrament; through it priests, by the anointing of the Holy Spirit, are signed with a special character and are conformed to Christ the Priest in such a way that they can act in the person of Christ the Head. (1)

The Catechism of the Catholic Church employs this expression in reference to the sacrament of Holy Orders.

1548 In the ecclesial service of the ordained minister, it is Christ himself who is present to his Church as Head of his Body, Shepherd of his flock, high priest of the redemptive sacrifice, Teacher of Truth. This is what the Church means by saying that the priest, by virtue of the sacrament of Holy Orders, acts in persona Christi Capitis:

It is the same priest, Christ Jesus, whose sacred person his minister truly represents. Now the minister, by reason of the sacerdotal consecration which he has received, is truly made like to the high priest and possesses the authority to act in the power and place of the person of Christ himself (virtute ac persona ipsius Christi).
Christ is the source of all priesthood: the priest of the old law was a figure of Christ, and the priest of the new law acts in the person of Christ.

Only men may be ordained priests and are able to act in the person of Christ the Head of the Church.

It is also the reason why a woman cannot be a priest; for a woman can in no understandable way become a "father" to the Church or represent Christ in persona Christi. - A priest must be able to act in persona Christi capitis (in the Person of Christ the Head of the Church)


What is the standard width for a website in pixels?

Question: What is the standard width for a website in pixels or where are statistics?
Comment: Fast forward to today and responsive web design is becoming the standard. Your website should adapt to the many different screen sizes. At least: HD Screen, Desktop, Laptop, Tablet, and Mobile.
Answer: There is no standard, despite most developers assume 1024x768 as standard.
There is a CSS grid system named 960grid which assumes the body width as 960px, then breaks columns in 96 columns with 10px, or 80 with 12px.
The problem is: PC screens are getting bigger and bigger always, slowly in some regions but are.
In the other hand, at tech-tops, you have smaller screens in mobile devices and netbooks.
Dealing with this reallity can be painful. There is CSS Media Queries to the rescue. Alternatively, you can use tag link (with rel handheld) to provide an alternative version to mobile devices.
Follow some reference links for you

http://www.smashingmagazine.com/2010/07/19/how-to-use-css3-media-queries-to-create-a-mobile-version-of-your-website/
http://www.alistapart.com/articles/responsive-web-design/
http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#rel-alternate
http://dev.w3.org/csswg/css3-mediaqueries/
Answer:
What is the standard width for a website in pixels?

Any number greater than 0 and less than infinity.
Current best practices for Responsive Web Design (RWD) are to support every device regardless of its width in pixels. Typically this involves using media queries to provide different styles for different ranges of screen sizes. The actual ranges used matter less than the design being consistent across sizes, and the site maintaining functionality across sizes.
Users are very likely to see different screen sizes without thinking much about it, so you want to minimize the amount of surprise when they drag a window to dock on half their screen, or happen to tilt their phone.
Some common width ranges used are:

extra small: 0-480
small: 480- 768
medium: 768-1024
large: 1024-1200
extra large: 1200+

These ranges are so common that I'd say they're practically a standard. Not all ranges need to be used, for example a site might be fluid width for anything below 768 and then fixed width and centered for 768+.
With all that said, be aware that the numbers you use don't particularly matter so long as the site is functional on whatever device a user chooses to view it on.

where are statistics?

Now to the tricky part, the actual data. If you're redesigning a site, the only data that matters is your own. What Wikipedia or Stack Overflow, or Google, or any-other-large-website-that-might-list-analytics-data says is irrelevant to your data for your site.
If your statistics show most users primarily using a particular range of device widths, you should probably focus on serving those users first. That all said, If your design is properly responsive you won't need to focus on any particular size at all.
For new websites or sites that didn't previously have analytics, heavily consider using a mobile-first approach, and be sure to use analytics so that you can properly adapt to your user base.

Old, Out-of-date Pre-RWD Version for Posterity's Sake
I am surprised that no one else has thought to mention browser size by google.
As for standards:
80% of viewers can handle up to 1000px width, but the ones that can handle more than 1000px width often don't. With wide screen monitors many people will align their windows to half the screen. Now that Win7 supports drag-n-dock, it's likely it will become even more popular.
As for height: your first impression to the user is at the top of the page up to around ~600px. However, most users know and expect content to fall "below the fold" and are willing and able to scroll.
If you want to go wider than 1000px, I'd highly recommend a fluid layout so that users on netbooks and smaller screens can still see the content properly.
~960px tends to be a standardized width, but really it depends on the content and the style.
Comment: If someone is interested, docking Google Chrome to one side on my 1920x1200 resolution monitor resulted in an usable area of 927px (leaving space for the scroll bar).
Comment: Link does not work anymore.
Answer: As others have said, there is no standard to this type of thing. Although, here are a few tips that will either make or brake your website:
I've always used either percentages or a worst-case-scenario build: smallest screen resolution that you're going to commonly come across is 800x600, and even that is rare. Anything below that is probably on a mobile device. 775px width is a good medium to use, or simply 80% if you know for a fact your website will still have appeal when it is scaled out to a larger screen. Most common problems is that the text content (When scaled out to 1600px widths) seems empty and short. Having your website to 775px width will fix that, however it might not look good with massive open space on either side.
NEVER make your users scroll to the left or right. Cutting off content of the sides is the quickest way to lose potential customers or readers.
Have your navigation somewhere near the top or in a place to where users don't need to scroll to find it.
And just a content tip; either have high graphics/low information or high information/low graphics. Trying to combine both of them always looks terrible.
Answer: The standard would be "as width/height as possible". It depends on the users screen :
http://www.w3schools.com/browsers/browsers_display.asp
Answer: It's helpful to know how popular screen resolutions are and then based your template based on general use by the majority... Personally I recommend using Responsive Design - that way your site works for all devices and all resolutions.
As from January 2013.

1366x768    25.4%
1920x1080   11.0%
1280x1024   9.7%
1440x900    7.3%
1280x800    8.2%
1680x1050   5.7%
1600x900    5.0%
1920x1200   2.9%
1360x768    2.1%
2560x1440  1.1%
Other 11.6%
Answer: Google Analytics records the visitor's screen resolutions. You can easily create a custom report to check what are the common screen sizes of your visitors. Here are stats (top 15) for my website for May 2013:
Rank     Resolution    % of Visits
----     ----------    -----------
   1     1366x768            23.0%
   2     1920x1080           17.7%
   3     1440x900             8.4%
   4     1280x1024            8.4%
   5     1680x1050            7.1%
   6     1280x800             6.9%
   7     1600x900             6.0%
   8     1920x1200            4.7%
   9     1024x768             4.4%
  10     2560x1440            2.3%
  11     1360x768             2.1%
  12     1280x768             1.0%
  13     1600x1200            0.7%
  14     1280x720             0.7%
  15     1152x864             0.5%

The stats vary from site to site depending on the type of traffic it receives so design accordingly. I myself prefer fluid designs with percentage width, 1000px min-width and a reasonable max-width.
Answer: There isn't really such a thing as standard, and the statistics are entirely dependent on target demographics. Aiming at technical people will generally result in better hardware and higher resolutions, less technical the reverse. But then there are phones, netbooks etc which have significantly lower resolutions than the norm in most cases.
For reference I usually assume a minimum of 1024x768 now.
In any case here are some:
http://www.w3schools.com/browsers/browsers_display.asp
http://www.w3counter.com/globalstats.php
Answer: I think , it depends to content of website .
For example if you don't need any sidebar, etc, and if you like minimal designs , you can set webpages width to 500px.
So, i don't believe (and don't like) standart about web layout's sizes.
Answer: 960 pixels is the most that's safe, as it works on a 1024x768 screen and leaves room for the scrollbar, and also works on an iPhone in landscape mode (because it pixel doubles its 480x320 screen to an effective 960x640, and doesn't have a scrollbar).
Answer: Given that most of today's widescreen monitors have a resolution of "1440x900" or wider, I would think that a 1280-pixel wide is becoming more the "standard" especially when it comes to displaying images.
NOTE: 1280-pixel wide was the width of many older 4:3 ratio 17-inch and 19-inch screens.
Comment: Most screens 'USED' not sold are 1366x768px due to macs and laptops. See my answer.
Comment: Since I cannot "add comment" to your answer yet, I'll ask it here.

What is the source of your list of screen resolutions?  I am curious.

Thank you for providing the 1366x768 info.
That is useful to know.
Answer: 960 pixels is  the best width for sites
Comment: do you have a source?


Do the parents of a convert merit in the afterlife for their child's decision?

Question: When my child was little, she wanted to know whether my parents, who are not Jewish, would go to Heaven.  I explained to her that the righteous of all nations have a place in the world to come.  But Rabbi Kalman Winter, zt'l, told my wife she could reassure our then young daughter that because I had converted, my parents would have a special place in the world to come.  What sources support the proposition that parents of a convert benefit from his or her's acceptance of Torah and mitzvos?
Comment: Anytime I cause/enable someone to do a good thing it counts to my credit, no?
Comment: @DoubleAA but did his parents cause or enable that?
Comment: @MonicaCellio Probably depends on the case.
Answer: http://www.shtaygen.co.il/?CategoryID=817&ArticleID=7936
InParshas Lech Lecha - Braishis 15:15 it says that when Avraham will pass away ואתה תבוא אל אבותיך בשלום. Rashi explains that even though Terach was an idol worshipper it says come to your parent, since Terach repented prior to his death.
The Marhasha was asked the following question when he was a child. How does Rashi know that Terach repented. Perhaps he remained a sinner however he received Gan Eden like it says in Sanhedrin 104a ברא מזכי אבא
The Marhasha answered that it says Avosecha אבותיך - Lashon Rabim - plural. That indicates that not only Terach was rewarded with Gan Eden also Terach's father, Nachor received Gan Eden. So you may say that Avraham was able to help Terach get into Gan Eden, however how was Nachor able to get in there? Therefore Rashi says that Terach repented and since a child helps a parent therefore Nachor also received Gan Eden. That is why it says Avosecha אבותיך - Lashon Rabim - plural.
Answer: a person is judged primarily for his own choices in life. this can be seen for example by rivka's father or rachel's father who were considered wicked people despite that their daughters were righteous. likewise, Chizkiyahu was considered a tzadik despite that his son Menashe was wicked.
It  helps to have righteous descendants, but this is not the primary factor by which a person is judged.
Comment: the question asks for sources that support for the proposition, but there are none here. In addition, you haven't sourced the claims you have made to the Bible; you've just alluded to episodes in the Bible. This is important because your core claim, "were considered wicked people," is probably not something you can source to the Bible.
Comment: The question is "What sources support [this] proposition?" I don't see how this answer addresses the question.
Comment: @IsaacMoses the bible is not enough?
Comment: @IsaacMoses fine, thought it demonstrates the principle for those familiar with the tanach. for less advanced, its at least a good lead


I'm trying to make a 1.5 litre batch of sugar wine (kilju), how much sugar do I add to it?

Question: I've been trying to make a 1.5 litre batch of sugar wine, but I don't really know how much sugar I should add. Thanks.
Answer: Ultimately, the answer to that question is going to depend on what you want the final alcohol content to be.  According to the wikipedia article on Kilju, the typical alcohol content is 5-7%.  As you probably know, you can calculate the alcohol level using an alcohol hydrometer by measuring a before and after fermentation reading.  Using this calculator, I got a 6.5% alcohol content with a specific gravity reading of 1.060 before and 1.010 after.
However, your question is related to how much sugar is needed to reach that specific gravity.  This article indicates that 1 pound of cane sugar in (1 gallon) of water should yield a specific gravity of 1.046.  This recipe for sugar wine looks pretty good, but it doesn't list the expected specific gravity levels.
In my mind, you are going to get the best results using an existing recipe and after you have successfully made it, start making changes to see what, if any, improvements you can make.


How much drainage is considered "well draining" for a bed that doesn't fully drain?

Question: I have a friend  who is building a sunroom garden, and we need to make sure the soil drains well drain into the overflow tank, while still allowing the soil to always be moist. How deep should the soil be so that it gets to the well draining sand, and brick scraps?
Comment: Depth of soil will not really affect drainage.  Soil components, sand vs clay, perlite, vermiculite: these will affect drainage.  How will you water this?  Drip irrigation, manually???
Comment: How would you do the design aspect then?
Comment: please give us some more details.  what are you growing, how did you intend to water the plants, where is the overflow tank you mention.....
Comment: he's thinking about the semi-permaculture stuff that can go in a 4 season sun room. I currently have him growing Garlic, and talked to him about also ginger, and turmeric, since it's a seasonal crop in 4A.
Answer: This is the same problem as a potted plant with the same best practices:

do not add a layer of gravel, crushed brick or sand at the bottom. This does not improve drainage but just creates a perched water table.
sand does not improve drainage as much as you think.  It tends to move in the soil and pack down
do use things which promote drainage: perlite or leca which is a baked clay product which is quite useful
do not use topsoil, use a soil less potting mix and add more perlite or leca
if your container is large enough you can use my favorite garden tool:

four inch drain pipe with sleeve
Run a section down the bottom of the pot
angle up to above the soil level and cap it
this allows you water from the bottom or, more importantly pump out excess water if overwatering occurs


Can a glass eye be an Arcane focus?

Question: Let's say a player's wizard character has lost their eye in some event and replaced it with a glass eye. Would they be able to use that glass eye for an Arcane focus while it is in their head?
Answer: Maybe. But not likely RAW.
An Arcane Focus is (PHB, 151):

An arcane focus is a special item—an orb, a crystal, a rod, a specially constructed staff, a wand-like length of wood, or some similar item—
designed to channel the power of arcane spells.

A DM may allow a glass eye if it was originally made to be an Arcane Focus to work (an orb is basically an eye), but I don't think I'd allow any glass eye to be a focus.
And PHB (203)

A spellcaster must have a hand free to access these components, but it can be the same hand that he or she uses to perform somatic components.

The latter quote is an explanation of how to access the component pouch/focus, but I don't think is is prescriptive in that you must use a hand. Just that if you have to use your hand, it must be free to work like that.
Slippery Slope?
Beware the fact that usually the Arcane Focus is something held in the players hand. By removing the need to hold it, you are making it much easier to do things that might have been problematic before. Feats like Warcaster are ways to mitigate holding something in both hands (dual-wielding or shield) and still allow for Somatic components (but it doesn't resolve the Material.) If the player has no need to use a hand for material components (by use of a glass eye), then it bypasses that potential restriction.
Actual Gameplay
In a current game, I've got a Paladin and my DM allowed me to tattoo my holy symbol as well as put it on my armor. This bypassed the need for material components when casting and I don't think it's made a huge impact on gameplay.
In the glass-eye case - make it a bit of a quest to find someone to make the glass eye arcane focus. That gives it some flavor, creates some tension and game around trying to find that person, and still eventually allows them to get what they're looking for.
Comment: Yes, @sharur, even in 5e Holy Symbols maybe worn or on the shield.  That is a benefit to their class.  Similarly, I believe the Eldritch Knight archetype of fighter can use their weapon as a focus at a certain level.
Comment: I would just mention that in editions prior to 5e (and I believe 5e as well), paladins and clerics were allowed to place holy symbols on their shields, so your example not entirely without precedent.
Comment: @J.A.Streich: Eldritch Knights don't seem to get a feature that lets them use their weapon (or anything else) as a spellcasting focus. They're stuck with component pouches, barring something like a Ruby of the War Mage.
Answer: No.
All spellcasting focuses require the use of a free hand to manipulate it, unless you have a feature indicating otherwise. See the following rules from the PHB/SRD in the Spellcasting chapter.

A spellcaster must have a hand free to access a spell's material components--or to hold a spellcasting focus...

The best you could achieve without special features is to pull the eye out, use it in your hand as a spellcasting focus, and then reinsert the eye (or I suppose just fondle the eye while it's still in the socket). However, that's only if the DM even allows the eye to count as an arcane focus. Since that's not part of its item description, it would be up to the DM to rule on the availability of that option.
Comment: @JAB depends. For flavor, if player is okay with it, I would offer "when you cover your real eye with your hand in a certain way, the focus becomes active and you can see out of the glass eye. It also lets you see the magical energy of the world better and that is what lets you cast". You end up with the same mechanic (need a free hand) while justifying the player's choice of focus.
Comment: You don't even necessarily have to remove the eye, if the issue is just a matter of having to touch it for an extended period of time. On the other hand, you'll look pretty silly poking your eye to cast a spell.
Comment: True, and noted. I added a parenthetical that I think handles that case, hehe.
Comment: @patrice That's a really cool use of thematically reskinning a pretty boring game mechanic. I might have to steal that for use in one of my campaigns.
Comment: @Bloodcinder glad you like it. It's all yours I am more used to 'lax' game mechanics (Nobilis or Steve Jackson's In Nomine, for instance) so i often go for those 'non-impacting reskins'. It gives the character a super nice flavor (especially if the eye removal becomes a kind of sacrifice to a god or a demon or something), without even changing how it mechanics work, and lets the player be something else than 'generic caster number 3' :p
Answer: A glass eye is fine
The rules specifically allow an orb to be a focus and one of the right size could be used as a glass eye. The rules do not limit where you can store your focus so in your eye socket is fine too.
However, you would still need a hand free to access it when you cast a spell that needed it.
Answer: A player that conceives of and takes the time to specifically design and craft (or have crafted) a glass eye for this purpose, should be given some consideration for creatively addressing what is otherwise an obstacle. It can provide significant story and character enhancement as well.
For example, instead of just saying "no" you might introduce a stylized "drawback":

"Over a period of several weeks, you finally manage to create a unique and powerful artifact. This
  glass eye can be used as an Arcane Focus without being held in the
  hand -- as long as it remains in place in your eye socket for 24 hours beforehand so as to remain attuned to your essence.
"However, it also constantly glows with an otherworldy energy that makes you extremely noticeable, day or night!"
Comment: An similar idea you could add: It is possible to come up with a homebrew and more mundane drawback due to only having one real eye, which might offset the benefit of not needing a free hand. E.g. -1 to Perception checks and Ranged attacks.
Answer: I think a specially designed glass eye would work.
If there were an issue with trying to have a weapon or something in both hands it could be resolved with the statement of the somatic components still needing your entire hand to function and for non somatic spells poking or placing your hand over the glass eye for a moment could be a solution.
Comment: Welcome to RPG.SE! Take the [tour] if you haven't already. Note that answers should be supported by evidence or experience. In this case, you should address whether this is first possible by the rules (even if just by summarizing what the other answers say) before suggesting whether it's reasonable to allow as a house-rule or how such houserules might work. If you do suggest houserules, you should explain how those houserules have worked in your own experience to support your answer.
Answer: if you google Arcane Focus this comes up."An arcane focus is a special item–an orb, a crystal, a rod, a specially constructed staff, a wand-like length of wood, or some similar item–designed to channel the power of arcane spells. A sorcerer, warlock, or wizard can use such an item as a spellcasting focus" so if its a Crystal eye and your playing 5th edition then i would say yes. you can use a fake eye if its a Crystal eye.
Comment: Welcome to the site! Just so you know, when we write answers here we like them to be backed up by rules text and citations. If you could expand your answer and reference the rules (maybe see if there are any restrictions in the books about what can be a focus) and edit those in, your answer will be much better. Once you reach 20 rep feel free to join us in [chat]! :)
Comment: Not just any crystal eye will do.  It needs to have been designed to channel arcane power.  This should increase its cost over a mundane crystal eye, but ultimately falls to the DM to allow (it's not a standard item for purchase) or forbid.
Comment: i think if the dm's good he'll let you do it. but maybe that would have an effect on your perception or give you a disadvantage on initiative. if you've lost your eye there's probably some way of getting it back or getting a replacement. perhaps by a wish spell. if you still have your eye i would not suggest ripping it out for this because it will most likely give you a disadvantage.
Comment: In general, I find that I do not suggest ripping your eye out for *almost* any reason.
Comment: On the other hand, if you're an orc, and a devout worshipper of Gruumsh, you're probably already ripped your left eye out, so you might as well. ;)

Can a glass eye be an Arcane focus?


MS SSAS 2008 and HTTP interface called msmdpump.dll

Question: I have following situation.

Computer A is my user computer on which I work. On this computer I would like to use Excel and be able to connect to SSAS thru HTTP.
Computer B is machine which holds IIS.
Computer C is machine which holds SSAS.
Computer A is under LAN A and ActiveDirectory A.
Computers B and C are under LAN B and ActiveDirectory B.
Computer A has access only to Computer B so that's why I have to use http proxy (msmdpump.dll) to get to Computer C.

SSAS is running as domain service account. I've set Computer B as "trusted for delegation" and ssas-domain service account as "trust this user for delegation to any service" and registered his SPN (http/hostname:81; http/hostname.domain:81).
When I try to connect to http url with Excel I get error. Also with SSMS I get error saying: unsupported data format.
With Excel I try to connect with Data-FromOtherSources-FromAnalysisServices. I type server name as http://server-ip:81/OLAP/msmdpump.dll and specify my domain credentials for LAN B I get: unable to connect to data source, reason, unable to locate database server.
But when I try to enter http://server-ip:81/OLAP/msmdpump.dll in browser I get soap fault which means it's successfully configured?
<code><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><soap:Fault xmlns="http://schemas.xmlsoap.org/soap/envelope/"><faultcode>XMLAnalysisError.0xc10e0002</faultcode><faultstring>Parser: The syntax for 'GET' is incorrect.</faultstring><detail><Warning WarningCode="1090584599" Description="The 'Invariant Language' locale for UI is not supported." Source="Unknown" HelpFile=""/><Error ErrorCode="3238920194" Description="Parser: The syntax for 'GET' is incorrect." Source="Unknown" HelpFile=""/></detail></soap:Fault></soap:Body></soap:Envelope>
</code>
Also I forgot to mention that I have enabled only basic authentication in IIS.
Answer: Problem solved. I had anonymous authentication enabled, I've disabled it now.


Will I fail a check-ride if I do a go-around for a short-field landing?

Question: Let's assume that I'm on a check-ride and my next requirement is to perform a short-field landing.
If I'm coming in for landing and it's obvious I'm not going to hit my mark, can I perform a go-around and try again? Would that be considered a fail?
Comment: At the risk of stating the obvious, if you are not going to make it and you *don't* go around you are also going to fail, but in a much more spectacular way.
Answer: In general, you get one free go-around.

First of all, any checkride which involves short-field landings probably also involves demonstrating go-arounds.  If you don't do one on your own, your examiner will have to ask to see one later.

Going around when it's obvious you're not going to make your point demonstrates good judgment.  It shows that you're not going to try to force the airplane into an unsafe situation just to hit your mark.  If the runway you're landing on really is a short field, continuing the landing attempt would not only be a bad idea, it would be unsafe, and the examiner would be correct in taking the controls from you, as well as failing you.  If the runway is long and you're simulating a short field landing, the same applies.

If you go around on a short-field landing and then go around on the next one as well, the examiner is going to start to wonder whether you really know what you're doing.  Let's face it, it should not take you three tries to get properly set up for a short field landing, unless perhaps if the day is remarkably turbulent or there is a strong gusty crosswind.  If that's the case, though, why in the world did you decide to take your checkride in those conditions?
Comment: This is almost verbatim what I tell students. It's true of any phase of the checkride, in my opinion. If you're in a situation you don't like, do what you would do if the examiner wasn't sitting next to you.
Comment: Yes I believe good judgement, aeronautical decision making, weighs heavier than making the perfect approach. You will need to demonstrate that you know how make a good short-field approach but you also need to demonstrate a go-around and my experience reflects that of Steve's in that the examiner will let you choose to go around on your own and count it towards that. Some will even purposely try to put you into a situation where you need to go around to see if you make the correct decision. Go-around is ALWAYS the better decision than a bad landing (unless you waited too long to clear trees).
Comment: "why in the world did you decide to take your checkride in those conditions?"  Maybe you didn't, and the conditions blew up once the checkride was already in progress?
Answer: In short, No.
I messed up both my short field, and soft-field landings.
I properly called and executed a go-around, and hit the landings on the second tries.
The examiner passed me, and gave me credit for executing properly when the landing couldn't be saved.
I think the important thing that he called out after the flight is that a Private Pilot's License is a "License to Learn" in a very literal sense.   You are not required to execute every maneuver perfectly to pass.  You are required to execute to a tolerance such that the safe outcome of the flight is not in question.
All instructors and examiners understand that learning is a life-long process, and recent events have repeatedly shown us how even the most experienced commercial pilots still need improvement on some skills.  As long as you demonstrate that you can control the plane, exercise good judgement, and keep everything safe, you're likely to pass.
The corollary to this is that once you have your license, you cannot believe that you are done and qualified.   Having a PPL just means you have a ton more to learn, but you can practice and learn a lot of that on your own, without an instructor constantly next to you.
Answer: No, you shouldn't fail if you're going around for a valid reason and the go-around is well executed. If you're well prepared, the way you operate on the checkride should be how you would operate if the examiner was any other passenger.
If you take a look at the Practical Test Standards for Airplane (FAA-S-8081-14B), there are a couple of areas that help answer your question. The biggest one is that Normal & Crosswind Landing (Task B, p. 43) includes this as a subtask:

the applicant [...] 11. Executes a timely go around decision when the approach cannot be made within the tolerances specified above.

...while Go-Around/Rejected Landing (Task L, p. 50) includes:

the applicant [...] 2. Makes a timely decision to discontinue the approach to landing.

That said, it's interesting to note that none of the other landing tasks include the "timely go around decision" subtask from Task B, so this possibly gives examiners a bit of leeway. You should be executing the go around as early as possible, at the soonest point you think that your setup is not correct. If you're too high on base, or you're not descending enough, or you forget to get your flaps in at the right time - reset the maneuver! And when you execute your go-around, make sure it is well executed (and to the PTS standards).
Ultimately, a lot of your checkride comes down to the criteria under Examiner Responsibility (p. 10):

Satisfactory Performance
Satisfactory performance to meet the requirements for certification is based on the applicant's ability to safely:

perform the Tasks specified in the Areas of Operation for the certificate or rating sought within the approved standards;
demonstrate mastery of the aircraft by performing each Task successfully;
demonstrate satisfactory proficiency and competency within the approved standards;
demonstrate sound judgment and exercises aeronautical decision-making/risk management; and
demonstrate single-pilot competence if the aircraft is type certificated for single-pilot operations.

Between "mastery of the aircraft..." and "demonstrate sound judgment", there is a wide range left up to the examiner. Most examiners, I feel, are pretty sympathetic to students' nerves and the day's conditions. If it takes you one (maybe two) go-arounds to nail your short-field landing, and the rest of the flight went well, you're set. If they have to take over because you're constantly going around... you're going to get to try again later after some more practice.
Answer: I did a go around on the short field for my PPL checkride. I was floating too much and even with a slip and s-turn I couldn't make it. So I went around and tried again. On my second try I turned base further downwind so I had a long final. Then I dragged it in for a spot on landing. The DE asked me if I knew why I was floating so much and I told him I had a tailwind but on the surface the windsock showed totally calm. He said I was right and that he calculated a 15 knot tailwind while I was flying. There was a lot of other traffic in the pattern so I didn't have the option of switching sides.
The DE told me that the go around was the right thing to do because he can't fail me for my landing if I don't land. He said if I was doing a lot of go-arounds for no reason that would be a problem, but otherwise a go around isn't a landing.


Does my internet speed matter?

Question: Does my internet speed matter if I use same circuit, nodes/hops?
There are 3 PC's:
1st one is connected to 100Mbps internet speed
2nd 500Mbps internet speed
3rd 1Gbps internet speed
In case all of them use same circuit the average ratio of HTTP request durations will be the same or will differ ?
If downloading something through Tor - the download speed in Tor network will be same or higher internet speed means higher speed in Tor ?
Answer: Your download speed will be bottlenecked by the speed of the slowest link. If the speed is truly terrible, you can try creating a different circuit but realize that the slowness is one of the costs for anonymity.

Does my internet speed matter?


High-accuracy digit OCR from a mobile screen shot

Question: Question
Is there an OCR solution that would run natively on a recent iPhone with better accuracy than Tesseract? It need only recognize enough to recover dollar amounts.
Objective
To scrape a table of dollar amounts from a screen image taken on a mobile device. We've examined all the frequently-recommended solutions, but they don't satisfy our constraints.
I'm starting here in case there's an off-the-shelf solution; if not, I'll try Stack Overflow.
Many of the objectives and priorities come from our client. It's fair to wonder whether these are wise, but I have to live with them.
That's the TL;DR summary. Below are the details, which are not of interest to everybody.

Priorities

The solution must run on a fairly-recent model of the Apple iPhone (let's say iPhone 6s minimum).
The accuracy of the interpreted characters is paramount.
There are ~30 numbers to retrieve. They are arranged in a table of three columns.
4.The format of the numbers may include currency symbols, grouping delimiters, and decimal separators. ('$', ',', and '.' in the US). Or any reasonable combination of these.
Expect the bitmap for each numeral to be ~25w x ~35h (10-pt Helvetica at 2x or 3x resolution). The font would be proportional, so separators will be significantly narrower.
The application needs some way of recovering the placement of each number in the table.
Run time must be under 10 seconds, ideally under 5. Usage will probably be rare enough that power consumption won't be a consideration.

Constraints
This is a proof-of-concept application. I am allowed sharply limited time and labor. I am strongly discouraged from resorting to services with ongoing or large initial costs, even though those may make sense for the final product.
What I've tried/considered
Tesseract
Tesseract is about 85% accurate in this application.
I've tried the native image preprocessor and my own I experimented with: Monochrome, various brightness and contrast, various blur/sharpen; the processed image looks plausibly distinct to me, with no empty spaces filled-in.
I can get the accuracy above 90% by correcting the output so it makes sense; I know the greatest magnitude, for instance, so too large a number with a leading 8 probably begins with a $.
The client isn't satisfied.
Tesseract in small pieces
The Vision framework in iOS 11 can identify the location of words and characters in an image, though it does not interpret them. Feeding the sub--images to Tesseract yields much worse results. I'm guessing Tesseract depends on context to resolve ambiguities.
Source scraping
There is no textual native format such as HTML or text PDF. I'm stuck with the pixmap.
Remote services
A remote service is less appealing than native processing, even though "free-trial" experiments yield much better results:

The client does not want to be out-of-pocket for the proof-of-concept phase of the product.
We can't rely on the client's managing his demos to fall within free-trial date or quantity limits.
As a matter of principle, we'd like the app not to depend on network availability or turnaround.
As a matter of principle, we'd like to avoid any user data going over the net and probably retained for third-party inspection.

ABBYY looks like a good option, except for these restrictions.
Machine learning
The problem is fairly-neatly contained:

Predictable type style.
No geometric distortion.
Sharp images to work from.
15 symbols to classify (0-9.,${space}{other})

A machine-learning model promises to be highly accurate, very fast, and easy to train.
The calendar and budget we've been allowed doesn't cover my learning how to train a model. However, we have access to a pool of computer-science students, one of whom might be able to do the training quickly and relatively cheap.
At this point, we're beyond the scope of Software Recommendations and into Stack Overflow or local talent. I'm including this option for completeness.
Comment: Dropbox made one for internal use: https://blogs.dropbox.com/tech/2017/04/creating-a-modern-ocr-pipeline-using-computer-vision-and-deep-learning/ BTW the situation, as described, looks like the client wants a very high quality difficult work for cheap. This doesn't usually end well. Good luck.
Answer: I think that the machine learning option using OpenCV, (although you might find the example of an alternative method here useful), is the best bet and the OpenCV library includes machine learning algorithms and has some great examples as a starting point such as https://www.learnopencv.com/handwritten-digits-classification-an-opencv-c-python-tutorial/ which is tackling a much more sticky problem.
OpenCV has the following characteristics:

Free, Gratis & Open Source
BSD Licence
Written in C++ but bindings for Java & Python
Supports Windows, Linux, Mac OS, iOS and Android
You could capture your training data & train your ML model with a desktop system and then export it to a mobile solution if desired.


Can non-alcoholic beer or wine not be haram?

Question: Wine has a few healthy anti-oxidants and I just like the taste of beer.  If we can distill all the alcohol out, is it still haram?  If not haram, would it be makruh?
Comment: Just so you know, a majority of beer drinkers (from which I am) consider that regular beer and non-alcoholic beer do not taste the same. You can find a many french recipes which includes stuff cooked with some wine, from which no alcohol remains. I do not suggest drinking distilled wine, though.
Answer:
If we can distill all the alcohol out, is it still haram?

First, this is not permissible, as per the hadith (as cited in an Islam Q&A fatwa):

Abu Talhah asked the prophet (ﷺ) about the orphans who had inherited wine. He replied: Pour it out. He asked: May I not make vinegar of it? He replied : No. -- Sunan Abi Dawud 3675 [grade: sahih] (sunnah.com)

(The rest of this answer is derived from my answer here for Coke.)
Alcohol occurs naturally in the food we eat and the drinks we drink under natural conditions (example ref.); it's detectable is beverages is e.g. Turkish markets [Gunduz et al., Halal Food and Metrology, J. Chem. Metrol, 2013 (pdf)]; and is even produced by our own bodies (e.g., Alcohol and Islam).  Thus, it's not realistic to totally eliminate alcohol.
Generally, if a substance is incapable of intoxicating even in large quantities, then it is not haram (insofar as to being an intoxicant).  There appears to be extra caution around alcohol derived from dates and grapes.
It's based around ahadith such as:

...I forbid you to drink intoxicants whether in small amounts or large. -- Sunan an-Nasa'i 5581 [grade: sahih] (sunnah.com)

An IslamToday.net fatwa, in the context of non-alcoholic beers, gives this way of understanding its ruling:

Sheikh Salman al-Oadah astutely observed: "The percentage of alcohol mentioned has no effect on the ruling. The ruling applies to the drink itself taken as a whole and not to its composition."

There are fatawa declaring both ways (One that declares it haram is: "all beverages that contain ethanol based alcohols are unlawful to consume" -- Islam.ru), but there's some that say these things are halal.
Beer
Specific fatawa saying non-alcoholic beer is halal:

... if something is mixed with alcohol but the alcohol is a small amount and does not have any effect, then it is halaal and does not come under the ruling of this hadeeth.  -- Islam Q&A, 33763
...non-alcoholic beer... though there is a trace amount of alcohol in certain brands... this minute amount does not in any way warrant classifying the drink as an intoxicating beverage. It would be extremely difficult for a person to drink enough of the beer for the alcohol within it to have any affect.  -- IslamToday.net

Wine

If it is clear that this drink is free of alcohol, there is nothing wrong with drinking it. Similarly, if treatment of khamr to remove alcohol from it was done by people who believe it is permissible to do that, then it is permissible to drink it. However we should point out that this treatment is something that is haraam for the Muslim to do according to the most correct opinion. -- Islam Q&A


Some keyboard keys stopped working when control pressed

Question: All of a sudden, some keyboard shortcuts seem to have stopped working in applications. The two I'm noticing it for are Ctrl+K and Ctrl+W. This is happening across multiple applications which should support those hotkeys.
I've tried running Spy++ to monitor the Windows messages, and it looks as if when Ctrl is pressed, no keyboard events are being sent for the K key press. However, pressing K without Ctrl does work.
This seems to be happening for the W and K keys, and also Arrow right.
I've tried using Windows Hotkey Explorer, but there's nothing obvious registered in there.
Any ideas to what could have caused this?
Answer: I ended up reinstalling the keyboard drivers and this fixed it.
(edit) Turns out that rebooting after installing the drivers has brought back the issue!


Extruder clicking Tronxy x5s

Question: Whenever it start printing the extruder starts clicking, I tried adjusting the voltage with no luck, it's still clicking. And it doesn't extrude a lot of plastic sometimes it even stops extruding but the extruder is still turning. Can someone help?
Comment: Possible duplicate of [Extruder clicks](https://3dprinting.stackexchange.com/questions/3185/extruder-clicks)
Comment: please see this answer  https://3dprinting.stackexchange.com/a/3205/9730  and use search box as you can find many answers for that particular problem
Comment: Probably temperature too low or nozzle too close to the bed, as per @profesor79's possible dupe.
Answer: The clicking you are hearing is either the stepper motor skipping steps or the hobbed gear losing grip on the filament.
Either way, it means that the filament opposes an unusually high resistence to be pushed forward.
A key information to be able to diagnose your problem is whether the clicking is on the firsts couple of layers or throughout the print.
If it is only for the first 1-3 layers the problem is likely to be the printing bed too high (or deformed), so that the nozzle touches it and the bed acts a "lid" on the nozzle preventing the molten plastic to get out.  If this is the case, adjust the printing bed to be flat and level (and the nozzle at the right height when homed on the Z axis.
If the problem persists throughout the full print the problem is likely to be related to one of the following:

the extruder not managing to get a firm grip on the filament (worn teeth, slack spring, ...)
the stepper motor being underpowered (this seems not to be your case, given that you have already adjusted the voltage)
a clog, adhesion, or restriction in either the bowden tube or the extruder, for which the best solution is disassemble, inspect and clean (eventually changing the bowden tube if it has been deformed).
Comment: I swapped the stepper motor with the x-motor and i put new filament in the extruder because the old one was damaged by the teeth of the xtruder and now it goes through the tube more easily. I also added a little washer between the spring and the casing of the extruder so it's a bit more tight. Now the clicking is gone but the filament starts slipping, so the extruder is turning but the filament stays where it is and it doesn't extrude a lot.
Answer: I have the TronXY X1, which uses the same extruder and firmware design as the TronXY X5. The clicking does not come from Voltage, but most likely a wrong set up of steps/mm or a lightly clogged nozzle.
Quick and dirty steps/mm

Start a print that you know clicks.
wait for the clicking starts (it comes from the extruder pushing against resistance and jumping back a step)
Go into Configuration > Extruder > Steps/MM
alter it down a little, listen if the constant clickig stops, alter again if needed.

Now, you need to make sure not to get into underextrusion doing this "on the go" fixing, and you really should calibrate your extruder.
Proper calibration
To calibrate your extruder, you could follow Thomas "Tom" Sanladerer calibration video or this rundown:

Move the printhead to a position where it can extrude freely.
heat up your hotend
load the filament (or have one loaded)
take a filament spool and make small marks on it an increment from the extruder's intake - for example with a CD marker. Tom uses 100mm (Ep for Extruded planned) for the calibration and adds 50mm to compensate for overextrusion, so places the mark at 150mm (L for length), allowing to calculate a compensation into both directions.
extrude 100mm of filament - it is advisable to directly send the G-code via a program here to use G92E0 to 0 the extruder and G1E100F90 for the extrusion
Measure the distance of your line to the extruder. Let's call this value R, for "Result position"
Now, we calculate Et (extruded truely): L-R=Et

Now, we have a length to compensate for. But what value we adjust? Steps/mm of course!

Either go into Configuration > Extruder > Steps/MM or send M503 to get the steps/mm from the configuration
lets call this value S for Steps/mm

Now, let's calculate the Sa, "Steps/mm adjusted":
* S*Ep/Et=Sa
Now, let's get it into the machine!
* Go into Configuration > Extruder > Steps/MM and adjust manually
 * make sure to save into EEPROM
* alternatively, send M92ESa , replacing Sa with your calculated value
 * Then, send M500 to store the value in the EEPROM
* third alternative: change the firmware configuration and reupload.
Answer: I also have this problem with the X5S, and it's not just on the first layer (which is sometimes finicky depending on the levelling). I've narrowed it down to a few things, and I've also noticed that it varies based on the print.
Possible Causes (and a suggested solution for each):

Bad quality hotend assembly: My X5S has a teflon-lined hotend, and besides that I don't like the rather small heatsink, mine came such that the bowden tube acts as the teflon lining, ie the lining and the bowden tube are the same piece. Already not a great design, but the implementation is slightly worrying. I'd recommend switching the hotend for a genuine E3D, I myself am planning on getting a Cyclops+ Aqua, which will be sure to resolve any existing issues.
Bowden tube is iffy: I'm not sure about this one, but I've noticed quite a bit of resistance in the bowden tube while loading filaments. I think this is causing excessive force on the Extruder motor (which I've noticed heats up quite a bit more than the other motors, to the point where I've added a heatsink to avoid possible damage). My solution is to swap the teflon for the blue Capricorn tubing from Trianglelabs.
Extruder setup isn't that great: As I mentioned before, the extruder motor tends to heat up a bit, and I just don't like the implementation of the extruder gears. I'd recommend switching this setup for a different one, if possible.
Print temperature and speed: I've noted that when I increase the temperature and decrease the speed of prints, the clicking reduces in frequency, but it does still occasionally click and my prints turn out horribly. This might be pointing to an issue with either extruder calibration or the flow rate during a print, as mentioned by other people here.

Cheers!
Comment: Regarding #1: it is actually BETTER to have the lining be the same piece as the tube as fewer parts that could move in the filament path is better. But indeed a full metal hotend is better. #3 what kind of extruder setup? #4: this is a partial fix for such behavior, yes.
Answer: I have an X5S and quite frankly, I never got it print properly because of these persistent issues. Thank you for the most excellent comments and suggestions. Lots to investigate.
I added an anycubic glass table but that takes longer to heat up. But i am unable to get adhesion on the first layers and the clicking kicks in shortly thereafter. I wonder if this thermal latency might imply a colder bed on first layers. I have tweaked the leveling so many times it is not funny. This is pointing to friction in the Bowden delivery system and the extruder itself.
I got an E3D that I must adapt. Too bad i cannot print those parts!
I have noted also a great variety of results from different printer filaments brands as well.
Comment: Hi Paul and welcome to 3D Printing.SE! This is not an answer, this is a comment, or a start of a discussion. SE sites are not forums, just questions and answers. Please take the [tour] and read [ask] so that you can formulate a good question to help you solve your problem. Most, if not all, issues you raise have been answered here before. There is even an answer for printing parts if you cannot print yourself!
Comment: On my X1 (same extruder & carriage),when did swap for an e3D hotend, I used the adapter of https://www.thingiverse.com/thing:2203334 - I did print the piece n a "unmodded" machine.

Extruder clicking Tronxy x5s


Calculating Probabilities for Substitution Ciphers using Frequency Analysis

Question: I have been trying to put together a tool that can take in cipher text encrypted via a simple substitution cipher and calculate the most likely "key" (that is, how the plain text letters were mapped to the cipher text letters).
I think I've had some success with an approach I've been using, but I suspect it could be a lot better.
What I've been doing to this point:
For a given mystery letter (that is, that which appeared in the cipher text), I calculated that it actually decrypts to 'a', given the frequency that this mystery letter appears in the cipher text. I did that by using Bayes formula to render it as the likelihood that 'a' appears in the cipher text the number of times that the mystery letter does (knowing usual frequency of 'a' in English). In other words, if we denote $X$ as the mystery letter and $F_X$ denotes the frequency that $X$ appears, then:
$$P(X = a \mid F_{X} ) = \frac{ P(F_X \mid X = a) P(X = a) }{ P(F_X) }$$
$P(F_X \mid X = a)$ can be easily calculated by using the binomial distribution mass function knowing the general frequency that 'a' appears in the English language. Without any other information, I assume that $P(X = a)$ equals $1 \over 26$. I neglected to divide by the bottom for reasons which I'll explain in a moment.
Then I did the same for every other letter; that is $P(X = b \mid F_X), \ldots, P(X = z \mid F_X)$. I summed up all of what I had calculated for this mystery letter, and then divided each one by the sum, to complete the calculation for each possibility.
Then I did the same for every other mystery letter. So, what I ended up with was a 26-by-26 matrix of probabilities that a mystery letter corresponded to a plaintext letter. It then becomes an assignment problem of selecting 26 elements, exactly one from each column and one from each row and trying to maximize probability for a particular key.
What I don't like about this (beyond that I'm generally inexperienced and uneasy on this topic), is that I feel that I could definitely do better. Each probability calculated for a mystery letter only takes into account the frequency of that particular mystery letter, and not the frequency of other mystery letters. I've thought about trying to do this as a Bayesian Network, but I feel unsure if that is valid, and I'm having a hard time getting my mind around it.
Thanks for any help and insight!
Answer: You might be interested in the paper "The Markov Chain Monte Carlo Revolution" by Diaconis, which you can find online.  In this paper, Diaconis shows how Stanford students were able to break a simple substitution cipher by using the Metropolis algorithm, using digraph frequencies.  Diaconis says an attempt based on the frequencies of single letters failed.