My hamster won't stop biting the cage

Question: My Syrian hamster is about 1 and a half years old and still doesn't stop chewing the cage, no matter what. I've given her chew stick, toys, hay toys and I've sprayed the cage she bites with hamster safe, no chew spray. Yet she still bites; she has a big cage with a lot of floor room. Unfortunately, she's not letting us to be handled as she gets stressed and bites, so I can't take her out for a 'play time'. I'm thinking of just getting her a glass tank, but I'm not sure and only want to do it as a last resort. What else can I do?
Comment: When you say she has a big cage. How much floor space does she actually have? You can try giving her cardboard and wood the chew on.
Comment: A syrian hamster needs a minimum of 100x40cm ground floor space. Additional floors do not count for more space. To get out could have other reasons too: hiding from wind or view, get to a warmer/colder space, boredom
Answer: This almost always means the cage is not adequate.
To the best of my knowledge, EU requires the Syrian hamster cages should have at least 0.12 m2 base area and 40 cm in height. It doesn't matter if your cage is double or triple layered. Extra layers give some extra opportunities for the hamster to play, but your base area should still be larger than 0.12 m2.
UK regulations are even more stricter: The dimensions of the base has to be 50x30 cm, yet RSPCA suggestions are 80x50 cm base area with a 35 cm height.
If your cage is smaller than these values, the hamster can be confiscated and you may be fined. Keep in mind that these are minimum values, not optimal values.
Meshed cages are preferred but if this is too expensive for you, you can buy a storage box of appropriate size and prepare a structure inside to allow the hamster to climb up and down.
Other than area, make sure that the cage bedding is not damp, there is a wheel big enough for your hamster to use and it has some extra entertainment, i.e., toilet rolls or kitchen towel roles, napkins etc. Think of giving them shelled hazelnuts. Syrians are strong enough to open a hazelnut shell, but not a walnut shell. Besides, it is fun to watch them go at the shell :)
If none of this helps your problem, you can consider leaving your hamster to travel freely in the house provided he is in a hamster ball. Hamster balls are considered safe if your house don't have stairs, yet it is a good idea to check on them every half an hour if they are stuck somewhere. If anything, stuck hamsters tend to relieve themselves in their ball and hamster urine is hard to remove from carpets.
I hope this helps.
Answer: I don't know if this is still going on, but my kid's hamster does this because it wanted a bigger cage or more play time. I started having her do it with her hamster and everything became fine!

My hamster won’t stop biting the cage


What are some famous mythological characters portrayed as guardians of something secret?

Question: Looking for mythological characters similar to Cerberus.
Comment: Hi and welcome to M&F SE, please take some time to take our [tour](https://mythology.stackexchange.com/tour). Interesting question but it misses one factor to me, how do you rank or choose the answer that suits you the most. Because I think there is a lot of answers that might fit here.
Comment: nagas are water serpents or water dragons. they guard treasures deep under the ganges
Answer: Gargoyle - is a fantasy and horror monster inspired by the gargoyle architectural element. While they were believed in mythology to frighten away evil spirits, the idea of such statues physically coming to life was a more recent notion. Like golems, they are usually made of magically animated or transformed stone, but have animal or chimera traits, and are often guardians of a place such as a cathedral or castle. They can also be depicted as vessels for demonic possession, or as a living species resembling statues.
Golem - is an animated anthropomorphic being that is magically created entirely from inanimate matter (usually clay or mud). The word was used to mean an amorphous, unformed material in Psalms and medieval writing.

If you look only for animate living beings, as example:
Minotaur - is a mythical creature portrayed in Classical times with the head and tail of a bull and the body of a man or, as described by Roman poet Ovid, a being "part man and part bull". He dwelt at the center of the Labyrinth, which was an elaborate maze-like construction designed by the architect Daedalus and his son Icarus, on the command of King Minos of Crete.
Comment: I don't think Golem can be considered guardians [of something secret]. And the Minotaur was imprisoned in the labyrinth, it wasn't guarding it.
Answer: Baba Yaga
In Slavic Folklore, Baba Yaga often depicted as an old woman is a keeper of the land of the dead.
On this blog or on Slavorum you can see many of the roles she tends to, but most importantly:

The Border Guard of the Dead-Lands
Baba Yaga is the customs officer of the land of the dead. Her hut is a
  kind of passport control. In that hut, the hero goes through all the
  necessary rites to begin his journey into the supernatural world. He
  washes in the sauna, which symbolizes the washing of a dead body
  before burial. He eats and drinks in excess, which is a hint at the
  traditional feast (pominki) held after a funeral. He always sleeps in
  the strange hut, because night is the witching hour, the time of
  passage from one state to another. And sleep is a kind of small death.

Here are more details about her, since she's not so well known:

The Hut on Chicken Feet
In the slumbering forest, in the deepest darkness, a hut stands on two
  chicken feet. In the hut, on the stove, Baba Yaga reclines on the
  ninth brick. Her legs are bony, her nose has grown all the way to the
  roof, and she's sharpening her own teeth. She looks like an old woman,
  but there something odd about her. Who is she? Is she even an old
  woman at all?
Baba Yaga is an ambivalent character, and that makes her very
  interesting. She's definitely scary—her face covered in warts, her
  crooked nose reaching all the way down to her hairy chin. She has
  hands like hooks, a hump on her back. Still, you can't exactly call
  her a villain. Yes, she constantly threatens to eat Ivan the Prince,
  or Mashenka, or Vasilissa the Beautiful, but she ever actually eats
  anyone. Really, her purpose in the stories is to be a magical helper
  to the hero, even if her help is not always what's expected.

Also, remember that her hut always face the land of the dead, you have to call it to turn around if you want to meet Baba Yaga and hope for a crossing right to the dead lands.
Answer: Griffins and lamassu were the first creatures that popped into my head. They are both widely depicted as guardians of treasure or powerful figures.
Griffins: https://www.newworldencyclopedia.org/entry/Griffin
Lamassu: https://www.ancient.eu/image/2295/lamassu-from-ashurnasirpal-ii-palace/
Lamassu, however, are not explicitly guardians of something secret. They are protectors of the palace, kings, queens, royalty etc. and are thought to ward off evil. Although, they could be interpreted or adapted as guardians of secret palaces, temples, or burial sites.
And, of course, dragons. Famous dragons such as Fafnir and Smaug in The Lord of The Rings are notorious for hoarding and guarding heaps of glittering treasure and secret artifacts.
Hope this helped, have a nice day.


Why is 3D printing with metals so uncommon?

Question: What are the differences between the processes of 3D printing with plastics versus metals? Why is metal such a problem? There are plenty of metals with low melting points. And AFAIK metal can be sprayed and directed in a number of ways such as with electric arcs and similar.
Comment: Your premise is flawed: 3D printing in metal is being done today, just not by hobbyists.
Comment: Low-melting-point metals are not what you want in the final product.  If you did,  then people would (a) have been using them in low-temp molds for ages, (b) have been printing with them already.
Comment: Maybe the demand is not really there because industry would use CNC machines for most manufacturing processes. Interestingly SpaceX's SuperDraco rocket engines are partly 3D printed using super alloy inconel: "On September 5, 2013 Elon Musk tweeted an image of a regeneratively cooled SuperDraco rocket chamber emerging from an EOS 3D metal printer, and indicated that it was composed of the Inconel superalloy" from Wikipedia.
Comment: currently there is also a RepRap in design https://reprap.org/wiki/MetalicaRap
Answer: Metals are used. Albeit, in machines that are much more expensive and complex than your run of the mill FDM style machines that you're likely referring to.
The main reason you don't see many or any metal printers(SLS) and DMLS are likely due to patents and costs. They use lasers and special powdered materials with a binding material them. See Wikipedia links.
For instance, when the patent for FDM type plastic printers expired, the market flooded with lower cost machines and parts. When the patents for SLS expire, expect to see more of those type of machines hit the market.
That all said, there is a small team in Europe called Sinterit working on an affordable SLS machine.  http://www.sinterit.com/ I'm not sure it can print metal. Again, maybe due to power requirements/patents/etc.
There may be others working on them too.
Answer: There are a number of practical processes for 3D printing in metals using various powder sintering techniques as described in other answers.
However it is difficult to use the sort of direct extrusion processes that you see with plastics because most metal alloys don't have the same sort of viscous, self adhesive phase that thermoplastics do. Most molten metals are fairly fluid, cast iron, steel, bronze and aluminium have a viscosity not too far off water when melted if there is an intermediate phase it is usually a slush mixture of solid and liquid phases rather than something which can be extruded and adheres to itself.
There is also the consideration that consumer 3D printing is designed for relatively inexpensive low volume production, so trying to do the same thing with metal is likely to be self defeating. In most cases it is likely to be easier to print a pattern in wax and plastic and investment cast it if you want it in metal.
Similarly in the case of low melting point alloys it is just as cheap and almost  easy to make a silicone mould from a master and cast it plus the fact that modern resins may actually be superior to low melt metals in most respects.
One example of this is is the models used for table top games. A decade ago these were injection moulded plastic for simple models and white metal for more detailed ones. Now they are almost exclusively cast resin.
There is also the fact that metals are inherently a bit more versatile than plastics in terms of rapid prototyping and fabrication. So there are more competing options for low volume manufacturing of metal parts than plastic ones.
In terms of direct equivalents to plastic filament extrusion in metal MIG welding is not that far off inn terms of process and a robotic version of the process is certainly reasonably plausible, however as already discussed the flow characteristics of metal mean that MIG certainly doesn't have anything like the resolution of plastic extrusion as there is a minimum voltage/current which is required to strike and arc.
There is also the fact that a decent MIG welder which produces anything like a consistent weld bead would start at around £500 with the 3 axis control on top of that, plus the fact that MIG generates a lot of fumes, spatter and UV radiation which needs to be managed.
TIG welding offers a bit more precision but is equivalently more expensive for the basic machinery and an automated setup would require additional wire feed equipment.
Comment: "Building up a component entirely from welding wire" was first tried around 30 years ago (source: personal involvement!). One major problem was the material properties of the end product. At best it was about the same as a component produced by basic sand-casting techniques - i.e. high porosity, poor grain structure, etc. If further expensive processes were required to improve the material properties, the whole concept became rather pointless.
Comment: https://m.youtube.com/watch?v=g8sT8ESfjrg check this out
Answer: I am not an expert on this topic but Metal 3D printing is available. Here are some images of 3D printed faucets.


Why did a moderator uniterally remove from HNQ 'Why command hierarchy, if the chain of command is standing next to each other?'

Question: Why command hierarchy, if the chain of command is standing next to each other? has already been well answered. So I ask merely out of curiosity.
Comment: All moderator actions are "unilateral" by definition.
Answer: The question, being about a YouTube video, is barely historical. It is also rather low effort, containing little in the way of preliminary research, nor attempts to tie the inquiry to a broader historical context, or even any intention to verify the historicity of a fictionalised portrayal. In fact, a moderator raised concerns over the lack of research, but the OP appears to have ignored it.
The net result is that the question is fundamentally one of the logic behind military practices, and a fictional portrayal thereof at that, rather than history. This is demonstrated also by the answers it received. Without intending any critique of their quality, most of the answers invoked logic or modern practices, rather than any application of historical methods.
For these reasons, this question is not particularly good fit on History.SE. While perhaps not to the point of putting the question on hold, it is nevertheless not desirable to feature it network wide.
Comment: @LangLangC No particular discussion in this case I'm afraid, since no one else was awake at the time. The question *had* been flagged for closure as being off-topic, which was declined. We may have to work out a procedure for more marginal cases, though I'd prefer to err on the side of inaction generally.
Comment: You might infer that I agree from other posts. But for discussing the procedure: was that flagged in any way, flagged for HNQ-removal specifically, was there a mod-discussion about it, (in mod-cat / behind the scenes)… ?


Which month follows the Adhik Maas?

Question: An "Adhik Maas" is an extra month in the Hindu calendar. What is the month after this month? There are texts on it but people have different opinion. I am confused.
Answer: A Luni-solar year is 354 days consisting of 360 thitis. Depending on the location of sun and moon with respect to the nakshatras we will end up with a situation like a adhik maas. Adhik maas is basically two full moons in the same group of nakshatras which constitute a month. Chaitraa maasa is when full moon happens in either Chitra or Swati nakshtra. If two consecutive full moons happen in Chitra and then Swati  nakshatra both the months will be called Chaitra. The next month after Chaitra will be Vaishaaka Maas. We can also land up with a situation of a full moon missing both the nakshatras in a group. Then this is a kshaya or non existent maas.  Practically the calculation of moon's motion is the most complex among all grahas.

Which month follows the Adhik Maas?


How does the trial of Jesus compare to the judicial standards of the epoch and of the modern times?

Question: I wonder whether Jesus was given enough opportunities to defend himself, whether his trial was fair and whether the investigation was thorough.  I want to know how it compares with typical criminal, political or treason trials of the time, both in Roman empire and worldwide, and also in comparison with the modern times.
Answer: No, no and no. But it doesn't matter.

He was guilty of what he was charged of. Blasphemy. Claiming to be God.
The thing he was guilty of did carry a death penalty under Jewish law.
The Jews couldn't actually administer the death penalty, they had to get something to take to the Romans to get clearance.
The Roman governor (Pontus Pilate) operated the trial as a political maneuver to stop a Jewish uprising (of the people that wanted to kill Jesus more so than of Jesus himself). He kept the peace by doing what the mob and religious leaders wanted. No claim was ever made of it being a fair trial.
Nobody stopped to consider the fact that his claim was actually true. The final proof of that was in the pudding, and that wouldn't be served up for three more days.

Nobody has ever claimed the trial was fair or investigation thorough. But nobody cared then and I'm not sure why anybody would care now.
Comment: It seems to me that claiming to be God was a crime under the law only in case such claims were false (am I wrong?). So in case he could convince the jury that he was in fact, God, he possibly could be set free. (By the way, did he really claim that he was God in the Gospels?)
Comment: And, no matter what Andrew Lloyd Webber might have you think, Pilate was generally not much better than a mob boss. He was brutal and, by the accounts of contemporaries, really didn't give a rat's behind about justice.  He hated his job, and everyone hated him.
Comment: Resurrection is my favorite flavor of pudding
Comment: So Jesus was not given enough opportunities to provide proofs and the existing proofs neglected?
Comment: AFAIK execution by stoning was at least tolerated to Jews. Stephen in Acts 6-7 was found guilty only by Sanhedrin, not by Romans, and there's no mention of any problem Sanhedrin had with killing someone. But cross was much worse death for contemporary measures than stoning, and with respect to Jesus' followers the priests needed someone else to do the dirty work for them. Plus God's will, of course.
Comment: @Pavel - The recounting of Stephen's stoning in Acts seems to indicate it was a mob action.  In other words probably, not a legitamite execution; however, no followup is every listed (other than Saul's further involvement).
Comment: @Anixx, according to Jewish doctrine, no person could ever be God, so anybody who claiming to be God is making a false claim. This is a difference between Jewish and Christine doctrine. As such, there is no provision in Jewish law allowing true claims to being God because (presumably) such a claim could never occur.
Comment: @Daniel is this doctrine based on the holy books? If so, do Christians recognize those holy books?
Comment: @Anixx, that's a good question, and perhaps it's not as obvious as I initially thought it was. I have asked [that question](http://judaism.stackexchange.com/q/28925/1713) over on Mi Yodeya.
Answer: Caleb just posted and I am saying the same thing, but so my typing does not go to waste:
When you read the gospels carefully the trail of Christ was principally held in secret by the High Priest and the Sanhedrin where false witnesses were brought in to trap Christ. They sort of bungled at their attempts but eventually his own confession that he was the Christ easily gave them what they needed to hastily condemn him as a blasphemer.    So to start of with the trial was rigged to simply achieve the murmurous desire of the religious leaders. However at the time of Christ the Sanhedran could not condemn to death, as the Jews were a vassal state under Rome. Under that government the Jews had to refer all capital crimes for a Roman decision.
As Rome did not care about their religious quarrels, the Jews had to further misrepresent the case to get their attention.  Therefore they insinuated that Jesus was a political rebel not willing to submit to Caesar.  Apparently he claimed to be 'King of the Jews', which meant he was like the Zealots who must be suppressed.  The Jews also put it this way so that if Jesus was set free it might appear that the Governor Pilate did not himself respect Caesar.    Basically the Jews gave Pilate no political choice.
On the other hand, like a sheep before the shearer Jesus chose not to defend himself as it was his purpose to die as an atoning sacrifice for sin.

Meanwhile Jesus stood before the governor, and the governor asked him, "Are you the king of the Jews?" "You have said so," Jesus replied.
  When he was accused by the chief priests and the elders, he gave no answer. (Matthew 27:11-12, NIV)

Now of course this trial would not stand in today's legal system, at least among first world countries, however,  judicially killing an innocent person back then was not entirely rare when we consider the many Christian martyr's just a few years later. Then again, to kill the only sinless man that ever walked this earth, while he being so meek, mild and perfect under every accusation can't really be compared to the injustice anywhere else ever committed in the history of the world. So in this sense there is no injustice quite like it, nor will their ever be.
Comment: +1. Your final paragraph was well worth restating my hurried points.
Comment: Matt. 27: 18 (charge brought from envy), 19 (wife's dream: "innocent man"), 23-24 (washing hands on the matter) indicate that Pilate knew that Jesus was not guilty.  Luke 23:14 ("no basis for your charges" [NIV], also John 18:38), 22 ("no grounds for the death penalty" [NIV]) further indicate Pilate's knowledge.
Comment: Well It could be asserted that the Jews could anticipate all the misery which Jesus teaching would bring to their people in the future (as there were numerous religious strifes before than already). But my question is not whether the execution was justifyed on moral grounds. The question is whether he did have enough opportunities to defend himself, to present his cause, whether his case was duly examined compared to the judical standards of the time both in Rome and outside?
Comment: I think you are claiming that the trial was unjust because he was sinless, but the jury seemingly could not know about that. So my question is whether his trial was better of worse in terms of quality compared to other trials irrespective of the suspect's own personality.
Comment: @Anixx - He was killed by Rome because the Jews pretended a man of peace was claiming to be a King who opposed Caesar. This was untrue and yet Jesus did not defend himself. The sinless part those committing the injustice were not mentally conscious of, although Pilate did sense the man was innocent which is why his hand had to be forced by those misrepresenting his fake crimes.
Comment: @Paul A. Clayton does this mean that he could be freed by Pilate if he tryed to defent himself?
Comment: @Anixx he could have been freed by Pilate on more-or-less a whim.  The consequences might have been: 1) a riot (and Romans favored civil order) and 2) loss of position and possibly worse for Pilate.  Also Jesus did state before Pilate that he was not a military threat (John 18:36--"My kingdom is not of this world").
Comment: @Paul A. Clayton given 100-grade scale, how would you assess the quality of the trial?
Comment: @Anixx Pilate listened to both sides, seemingly held the trial under normal rules, and even offered a 'pardon' if there was public support, but knowingly condemned a man not guilty of insurrection (and claimed not to be responsible) while pardoning one guilty of insurrection by public demand.  100% on form, 0% on quality.  The Sanhedrin trial appears more problematic; the accusers and judges were not distinct and the accusers sought false evidence; I don't know if daybreak trials (Luke 22:66) were typical or if that was an attempt to "pack the jury"--was Nicodemus timid like Jn.3 or absent?
Comment: This is getting chatty. Tried to create a chat room, but failed.
Answer: The other answers are good but I'll toss in a bit more.
Pilate suspected that the case brought before him was really an internal dispute over the Jewish religion. He wanted no part in these things (being perfectly happy for the Jews to be mired in intramural conflicts).
So he questioned Jesus enough to confirm what he already suspected, and went out to tell Jesus' accusers to get lost (in polite terms of course).
This is not because Pilate was honest, or that he was all worked up about justice, but because even the crookedest judge will try to maintain the appearance of justice provided nothing important to him is at stake.
Jesus' accusers then played their ace: If Pilate did not do as they demanded, they suggested that Caesar would hear reports that Pilate was tolerating rebellious activity against Rome. Pilate knew that Caesar probably would not believe such an accusation without independently verifying it, but he also knew that if Caesar wanted him gone for completely unrelated reasons, the accusation would do. So he folded.


Front end module editing

Question: What would be the best way to have front-end edits open on a blank page? When I train a client to use front-end editing, they get confused when they have to scroll around to find the edit screen which always appears in the main content area. Couldn't we make this to always open so it ONLY displays the currently edited content?
Thanks!
Comment: If one of the answers resolved your issue, please award it the green tick. https://meta.stackexchange.com/a/5235/352329 Also, please take the [tour].
Answer: The simplest solution would be to create a Template Override for the following file:

components/com_config/view/modules/tmpl/default.php

Once done, in the override, add the following PHP:
JFactory::getDocument()->addScriptDeclaration("
    document.addEventListener('DOMContentLoaded', function() {
        var form = document.getElementById('modules-form');
        form.scrollIntoView({behavior: 'smooth'});
    });
");

This will automatically scroll the user to the module edit form.
A more advanced approach would be to create a system plugin that checks which view and controller are currently in use, and then execute the above code, like so:
$jinput = JFactory::getApplication()->input;
if ($jinput->get('option') === 'com_config' && $jinput->get('controller') === 'config.display.modules')
{
    JFactory::getDocument()->addScriptDeclaration("
        document.addEventListener('DOMContentLoaded', function() {
            var form = document.getElementById('modules-form');
            form.scrollIntoView({behavior: 'smooth'});
        });
    ");
}

Answer: You can force joomla to use a different template (a simple template maybe) every time user trying to edit the module. I created a plugin for similiar purpose but for editing article in here.
You can modified the plugin to support module editing by modifying the editortemplate.php file at lines 23 - 26, from
$view     = $app->input->get('view');
if ($view == 'form')

to
$view     = $app->input->get('view');
$controller     = $app->input->get('controller');
if (($view == 'form')||($controller== 'config.display.modules') )

Comment: I had already installed the Editor Template plugin and it worked for articles. Now with your modification, it works with modules also! Perfect! Thank you!

Front end module editing


「たとえ + ても」 vs just 「ても」, what is the role of たとえ? Is it just emphasis or something more?

Question: 「たとえ + ても」 vs just 「ても」, what is the role of たとえ? Is it just emphasis or something more?
Answer: You could possibly label the usage as "just for emphasis", but without 「たとえ」, the contrastive conditional simply would not sound "complete" or even "right".  If the other native speakers here disagreed, I would like to hear from them.
That is because, according to me, being emphatic is an essential part of the contrastive conditional to begin with.  Imagine eliminating the word "even" from the English contrastive conditional sentences using "even if".  Would the sentences still sound the same way without "even"?  I would doubt that very much.
Thus, I would suggest that you learn 「たとえ + ても/とも/としても, etc.」 as a set phrase.
Nothing to do with the question, but you will occasionally encounter the word's alternate spelling 「たとい」.
Comment: Thank you for the answer, I have a small question about "emphatic" here, what does it actually mean? I see it often as "emphatic particle"  etc and I am never sure what does author actually mean. I tried looking for that but it feels as if every person means something different by that "emphatic". Also, to sum up, ても/でも by itself is shortened version of the whole phrase being たとえ/たとい + ても?
Comment: 私は呼応の副詞の意味は強調のためじゃなく、次に言うことが本文でなく副詞節にすぎないことを示す前置きみたいなものだと思います。これが disagree なのか agree なのかは微妙ですが。

「たとえ + ても」 vs just 「ても」, what is the role of たとえ？ Is it just emphasis or something more?


Is it a good practice to use a throttle limit of 90% for racing builds?

Question: I had read somewhere that it's a good idea to set a throttle limit of 90% for racing.  The reason given was that, in the last 10% of the throttle, the cost/benefit ratio for power to thrust would not be worth it.  Is there any truth to this?  If so, what is the recommended throttle limit for any build/all builds?
Answer: The reason why this is recommended for racers is likely due to the fact that during these high-throttle punches, the voltage of the battery sags from the load and so more current is pulled from the battery to increase the motor RPM.
Power is equal to VI when V is voltage and I is current, which can be rewritten (by substitution of Ohm's law V = IR in for V) as I^2 * R. This means that if more current is drawn to compensate for a voltage sag, the power consumed by the motors increases by a greater amount because the resistance of the circuit is constant. (for all intents and purposes) For example, in the hypothetical scenareo that twice the current is drawn, four times the power would be consumed. This results in quicker battery drain.
The 10% figure that you've heard isn't a hard line, but rather just a suggestion based on experience with miniquad hardware and its capabilities. This recommendation isn't just specific to racing; all quads would benefit from the efficency (energy extraction from the battery) boost from rarely using the top XX% of the throttle range. However, this is often more important in racing scenareos where it is often necessary to make the most of the energy in the battery pack you're using because you've selected the smallest and lightest one possible and need as much energy as you can get to complete the course in record time.
Comment: @RobinBennett It's a bit of both, really. None of these batteries are *really* intended for such hard use.
Comment: Is this actually good practice, or just a hack that's applied after choosing motors and props that are too aggressive for the battery?
Answer: There are two reasons to throttle limit, one is obvious, the other is not necessarily obvious.
The first reason is that both thrust and amperage draw grow rapidly at higher throttle values, and particularly because of the interaction of battery sag and the wattage motors will pull at the top end, it is possible to exceed the amperage of battery and electronics operating efficiently (or operating without letting out the magic smoke).  For this reason, the general rule of thumb for racing 5" quadcopters is that the point beyond which 38k RPM would be met is excessive, and unlikely to contribute meaningful thrust beyond that point.  Since carrying a large enough battery to provide extra power is usually a significant weight offset (greater than 5% craft weight to jump up to the next highest capacity within the same battery voltage and discharge lineup.
The second reason is less obvious, but very relevant for racers - resolution on the sticks.  By properly limiting throttle output, it is possible to create better resolution on the control gimbal by having the full stick travel focus on a narrower section of the available throttle power.  Correctly is important here, you don't want to limit throttle in a way that converts the top N% of stick travel into a dead zone.
For me personally, I run a 94-96% limit at the transmitter, even when I want full throttle, because at these input throttle levels, at least one motor will be at 100% because of the PID loop compensating for some attitude adjustment while flying, and the way that mixer works, I can't actually get more overall thrust out of that quadcopter because it has one motor already maxed out.
Finally, running 'excess' KV setups where, for example, you are leveraging the ability to run 2500KV batteries on 5S or 6S packs that you can take advantage of the higher voltage and efficiency of lower amperage draw in most flight regimes for running those batteries, you can limit the motor output (again, 38k RPM is a solid guideline here) you will want to limit the motor output at the flight controller (i.e. never ask the ESC for a throttle setting above a value at which the ESC or motor will hurt itself, desync, overdraw batteries, or turn the propeller into a audible goose-honk source), then you can work to add resolution to the sticks through that same method if you so choose.
Resolution is the less obvious, but often more valuable reason to focus on this for racing applications, because having more stick travel range to make fine adjustments in will allow for more accurate corrections.


Should I transplant a lemon tree from the ground to a pot for winter

Question: My lemon trees are about 3 inches tall ( as I planted them from seed ) we have cold winters here and am scared that they will freeze. I planted them in the ground about 3 months ago.
Comment: When did you plant them in the ground?
Comment: About 3 months ago
Answer: The easiest answer is yes.  If you are uncertain if your area can grow citrus, then dig it up.  Most Citrus require USDA Zone 9 or warmer.  Even so, this is the temperature where the cold will kill the entire plants.  You need protect from becoming defoliated or killing your crop in the winter.  This is going to be 1 to 2 zones higher.  Meaning Zone 10 or 11.
I know some gardeners in border line areas cover them in remay (white garden cloth) and use incandescent lights, like Christmas lights to keep them warm only during the really cold spells, but they also grow them right up again the house.  I have a attached a video that gives other options like wrapping it in a sheet or light blanket, using space heater for those cold spell, anything to keep it warm during those cold spell.   Options for protection citrus
So, the easiest and best answer is to dig it up.  Grow it in a pot.  Lemons are very easy to grow in pots.  If you keep it inside in the winter mist the leaves often to keep away spider mites.  Use the kitchen hand sprayer to hose the leaves tops and bottoms off, about once a month.  This is an excellent way to keep away spider mites. They love citrus plants.
Comment: Thank you for the answer! I will dig them up and put them in a pot.


Importing Existing Users with Passwords

Question: I have an existing legacy PHP site of 15000 users with base64 hashed passwords , I would like to import all these users into the new wordpress site with their passwords , What would be the best approach to realize this?
Praveen
Answer: You can use wp_insert_user. Since your old database has passwords in base64, you can easily get the original password string using base64_decode.
$new_user_data = array(
        'user_pass' => 'password',//pass your decoded password string
        'user_login' => 'username',//pass your username
        'user_email' => 'email',
        'first_name' => 'firstname',
        'last_name' => 'lastname',
        'role' => 'author'//if you want to specify a different role other than default one
);
wp_insert_user( $new_user_data );

You need to format your old data in csv or xml or text file and read and pass them accordingly. And don't try to import all 15000 users at once. Do this in several parts. Also sleep() function will be quiet good to give the server some rest.
Answer: WordPress uses MD5 for encrypting the passwords. So I don't think direct import of users will work here. You can either write script to import users with new auto generated passwords and fire emails to all.
OR
Use the 'authenticate', 'wp_authenticate_user' filter hooks to validate users with the existing table of users. http://codex.wordpress.org/Plugin_API/Filter_Reference/authenticate
This plugin might help: http://wordpress.org/plugins/external-database-authentication/
Answer: WP using md5 for encryption and you have base64 so I don't think that you can directly import the same password.
But as we all know that base64 can be decode http://www.php.net/base64_decode so it is clear that we can import your old password as well
But there is several WP plugin which will import users from CSV file to WP database and with new password. And system will send new credential notification mail to that user as well. http://wordpress.org/plugins/members-import/ this plugin can help you to do the same.
In this plugin where password field data from CSV file is used pass that string to base64_decode() function.
If you are importing same password then no need to send notification mail.

Importing Existing Users with Passwords


Metamask from web to mobile

Question: I have use my PC to manage MetaMask (ie. chrome extend). compound.finance also connect to my metamask wallet. I want to  manage my account by mobile and at PC that I install metamask mobile in andriod. But the mobile version create a new wallet to me. How to use mobile to manage my previous wallet ?  Will the compound finance cannot connect my wallet after use mobile version ?  Thank you.
Answer: You'll need to save / backup your seed words (12 random english words that are in your Metamask settings) from your desktop, and import them into your mobile metamask.
Better yet, ask Compound to support a web wallet that is backed up remotely (e.g. Portis, Fortmatic, Torus, or Democracy)

Metamask from web to mobile


How do I use green screen effects in cyberlink powerdirector and put the video in the green part?

Question: I'm a noob, so explain like I'm 5 years old.
Comment: Hi Texas - please read the posts in the Related sidebar to the right. These are the ones that would come up when you asked your question. And this seems like a dupe of a few
Answer: Summarizing from How do I use the chroma key feature to replace a green screen background in CyberLink PowerDirector?:

Put the video or image you want to use as the background (what will replace the green) on Track 1.
Put the video that has the green screen on Track 2.
Double click on the clip with the green screen background to open in the PiP Designer.
Select the Chroma Key tab and then Enable chroma key
Click on the eye dropper button on the Chroma Key tab and then select the (green) color in the image or video clip that you want to replace/make transparent.
Adjust the sliders until the green completely disappears.

This video might help explain it better.


Why can we see light further than it shines?

Question: This is a question I've been thinking about for a while. If I'm standing in the middle of a straight road, during night, I can see a car coming towards me because of its lights even if it is kilometers away. Notwithstanding, the driver can not see me because the car will brighten the road only few hundred meters further. What physics properties of the light causes this phenomenon?
Comment: will you say the same when a mirror is placed at your position ?
Comment: Why do you not ascribe this effect to your eyes and the driver's eyes?  You see bright pinpoints of light in a vast darkness, so your eyes are [scotopic](https://en.wikipedia.org/wiki/Scotopic_vision).  The drivers eyes are adjusted to the brightness of the reflection from the first several meters, so are [photopic](https://en.wikipedia.org/wiki/Photopic_vision).  These give very different lower bounds on the brightness of visible objects.
Comment: [Closely related](https://physics.stackexchange.com/q/243565/44126), and addressing the fact that reflected intensity goes like $1/r^4$ unless you have focusing optics that create some beam waist.
Comment: @rob: Yes.  To continue the driving example, consider "cat's eyes" and corner reflectors in signs &c that change the inverse 4th power to approximately inverse square.
Comment: you may find this video of interest: https://www.youtube.com/watch?v=Bi_Tp1H9CDs .  Like others have said, if your shirt was a retroreflector it would be quite easy to see you.
Comment: @EricTowers this is one of the factors, but not the major one. If the car is parked at the edge of Grand Canyon (is it legal?...), the cliffs on the other side will not look bright.
Comment: Just think for one second about the brightness of the light coming out of the headlights, and the brightness of the light that your clothes reflect back to the car. You should have the answer immediately.
Comment: @eps thank you for the amazing video :)
Answer: Mainly because the driver sees the much brighter road right in front of the car, which is reflecting a greater portion of the light from the headlights. The light reflected from kilometers away is much less intense. The drivers eyes are not sensitized to the less intense light from farther away when they are mainly seeing the more intensely lit road in front of them. There is also the fact that the light you see from the headlights is much more intense than the light that the driver sees reflected off of you. This is due to doubled distance of the reflected light traveling with intensity lowering with the inverse square law https://en.wikipedia.org/wiki/Inverse-square_law#Light_and_other_electromagnetic_radiation , and because part of the light that reaches you is absorbed and part of it is not reflected directly back to the driver.
Comment: And also because the light is reflected diffusely (scattered in all directions), and not directly back to the driver. If you were a flat mirror at the correct angle, you'd appear much brighter. That's why staring at a person standing in sunlight is not blinding, but staring at the sun in a mirror is.
Comment: @BlueRaja-DannyPflughoeft or, instead of being a mirror "at the correct angle", you could have a back-reflecting surface, similar to the high visibility vests.
Comment: Also, headlights emit light in a pattern where most of it is aimed downward toward the road extending to a few hundred feet ahead. Much less light shines higher up and farther down the road. It's enough to be seen from miles away, but not enough to illuminate anything for the driver. This is by design so that an oncoming driver will see the car's headlights but won't be blinded by them.
Answer: Let me try to combine the existing answers into a full picture.
There are four effects which make you perceive light reflected from a distant object much weaker than a direct light at the same distance:

Only a small fraction of light is reflected from most objects.
The light is reflected isotropically, so only small fraction of light is reflected in the direction of the car.
The total distance traveled by light is twice the distance between the car and the object.
Pupils adjust the vision sensitivity to the brightest object in your view: that will be the objects close to your car. This makes farther objects harder to see, even if they are somewhat lit. If you in turn look at a distant car, the brightest objects will be its lights and you will see them easily.

(@Vid provides calculations explaining points 2. and 3.)
This is why retroreflectors (like street signs, or reflective vestments) are so much more visible, because they address points 1 and 2: they reflect the light well, and they reflect it at the direction of its source. At the same time presence of a street sign, or incoming car lights in your view may make other objects even more difficult to see.
Comment: technology connections just did a nice short video on how retroreflectors work : https://www.youtube.com/watch?v=Bi_Tp1H9CDs
Comment: This is good, but you're still missing the effect of our eyes dynamically resizing to let different amounts of light in depending on the ambient brightness of the environment. If you added that as a #4, then this would be the most complete answer.
Comment: @spacetyper That's a good point, thanks!
Answer: Well, we know that the density of light (flux density) decreases with $r^2$. We can assume that the car light is an isotropic source with power $P$. So we can see, that the flux $j$ at given distance, where there is a mirror is:
$$
j_0=\frac{P}{4\pi r^2}
$$
So, for understanding of the problem we can assume, that the light isotropically reflected from the mirror back to the driver.
The flux density of reflected light, when it reaches the driver will be:
$$
j=j_0 \frac{1}{r^2}=\frac{P}{4\pi r^4}
$$
The density of reflected flux depends on size, shape and albedo of mirror. But the main phenomena, why driver can't see the mirror, while the mirror can "see" the driver is, that the first flux decreases with $1/r^4$ and the other with $1/r^2$.
Comment: I don't understand why it's $r^4$ with a _mirror_.  A mirror at distance $r$ should behave the same as if there were a second driver $2r$ away, so the intensity should drop with $(2r)^2 = 4r^2$. With diffuse scattering, though, it's like a second light-source, so $r^4$ makes sense...
Comment: The whole point is that a car is _not_ a mirror. That's why you get $1/r^4$ instead of $1/(2r)^2$.
Comment: This is similar to the [radar range equation](https://en.wikipedia.org/wiki/Radar#Radar_range_equation), which also has an $1/r^4$ dependency on the distance.
Comment: @BlueRaja-DannyPflughoeft In the far-field limit, the mirror is effectively a new aperture in the optical system. If you have a flat mirror that's a square of side $a$, you can ignore these effects if you're observing the reflected light from a distance like $a$, as when you're a meter from the big mirror in your bathroom. But if you're detecting the reflection from $1000a$, even light which left the mirror as a well-collimated beam will have diverged due to diffraction.
Comment: Shouldn't it be $j \propto \frac{P}{4\pi r^4}$? Your equation is dimensionally incorrect.
Comment: But there's more to it. While the density of light from the car's headlights decreases proportionally to $r^2$, our eye is a lens, and the space the distant headline occupies on our retina is also inversely proportional to $r^2$. This means that the effective brightness stays constant, so the headlights will become invisible only if the projected area becomes too small (or due to atmospheric effects which we have ignored so far).
Comment: @OlivierDulac - that's the syntax for delimiting LaTeX math expressions; if you're seeing dollar signs, instead of nicely formatted mathematical expressions, the page didn't load correctly, try refreshing.
Comment: @BlueRaja-DannyPflughoeft I was thinking what is the counterexample for $4r^2$, but I dont know none within linear optics... I mean if we go outside of limits we are dependent on the shape of mirror. Try thinking about light source and mirror as a black bodyies, which are absorbnig all light recived and then emit it isotropicaly. Becouse if we think about this problem like in optics we can assume, that there is a giant parabolic mirror, and the car driver will actually see it, if it will be centered correct. So this is not the case in this question
Comment: @Vid The person reflecting the light is not a mirror, also your answer only attempts to  cover one part of the answer.
Comment: As mentioned in other coments... It's scatered reflection, eg. at least in 1/2 of space... Probably the use of term "mirror" vasnt the best. But if we have retroreflector, all the light is reflected back in the direction of source. In that case it would be $1/(2r)^2$. I intentionally  talk about the dimming of light, becouse it is the most significant efect, and also gives the highest order in equation.
Comment: @Vid What of diffusion of reflected light from a person, rather than a mirror or retro reflector. Light scattering must also be considered in the context of the question.
Comment: I do not understand one assumption. While we can assume that the pedestrian is reflecting the light more or less isotropically (because why not - though it is not likely to reflect it to its back), why is this such an assumption for the car beams? Even the name "beams" suggests that the light is emitted in a directed way.
Comment: @WoJ The light from headlights is reflected  conically forwards by a shaped mirror behind  the emitter, but the rays are not aligned as in a laser. So they still lose intensity by the inverse square law.
Comment: why do you use dollars ($) instead of backquot (`) ? it is really hard to read
Comment: @FilipMilovanović: thx, it was the same for a few refresh, but now I tried and indeed the $$ disappeared and the equation appears in a mathematical way now
Answer: To clarify some things, The answer provided by @Vid is partially correct in that the information holds true only if you can assume an isotropic point source.
I design headlamp optics for a living and a low beam headlamp beam pattern is not anything close to an isotropic point source.  It is more of an elliptical shaped beam that is very narrow in the vertical direction (~10° tall) and in the horizontal direction it is wider (~±30°) , but still narrow compared to an isotropic point source assumption.
The key photometric quanitity to consider when analyzing the transport of light flux from a headlamp is the luminance.  The luminance is defined as the luminous flux per unit solid angle and unit source area.
$$\frac{F}{(\Omega)(m^2)}$$
The luminance of a source will remain constant from the source to the observer absent any intervening media (like fog) so that the perceived brightness of direct observation of the oncoming headlamp at night is very high. It should be noted here that brightness is not a photometric term, but is a psychophysical term that relates to a sensation - A headlamp will be perceived as not bright during the day, but very bright at night.  Thus the luminance is the physical quantity we want to analyze as it relates directly to brightness.
When the light from the headlamp hits a person there are 2 factor that dramatically cut the luminance of the reflected light from the person.  The first is that the total flux being reflected by typical clothing material is probably around 20% or less (I don't have exact data for that, but dyed textiles typically fall near this number).  So immediately, you have cut the luminance of the reflected light down by ~1/5th compared to the direct oncoming light.  The second factor is that textiles will have a diffuse reflection so the solid angle in the denominator of the luminance will be increased.  If it is a perfectly diffuse reflection, the solid angle will be a hemisphere or 2pi steradians.  Compared to the original solid angle which is approximately .005 steradians, you have now reduced the luminance of the returning signal by over 3 orders of magnitude.
So when you combine the reduced reflectance with the diffuse reflection of the clothing, the returning luminance is very low and likely not detectable under normal observation conditions.
If on the other hand you had a specular flat mirror at the same distance as the human, assuming parallel ground and the mirror normal to the ground, the driver would see almost no light reflected back to the driver.  This is beacause the light for a low beam headlamp is nearly all aimed at the horizon or lower (there is a small amount of light above the horizon for seeing overhead signs), so the mirror reflection will maintain the luminance, but will not direct it back to the drivers eye.   If you turn on the high beam in this case though, you will most likely see a very bright reflection back from the mirror because the light for a high beam is concentrated at angles near zero degrees to provide maximum seeing distance for a driver.  The mirror then reflects that light back to the driver at almost the same luminance (a small reduction for reflectivity of the mirror) so it will be seen as being as bright as the human observer standing by the same mirror looking back at the car.
Comment: You're missing my point. I am trying to divorce _engineering_ considerations (e.g., the efficiency of the headlamps) from the _theoretical_ aspects that pertain to the OP's question. You can increase flux density from a bare bulb by adding optics? I can increase it by declaring my hypothetical point source to be brighter. But the numeric value of that flux density doesn't even matter: We want to find the _ratio_ of intensity that the pedestrian sees from the headlights to what the driver sees reflected off the pedestrian's clothes, and we want to explain how that ratio scales with distance.
Comment: Re, "...not anything close to an isotropic point source." Suppose we put an isotropic point source behind a mask with an elliptical-shaped hole in, such that it casts a beam that is ~10°  tall and ~30° wide. I don't doubt that a designer of car headlights such as your self would find that to be a horribly inefficient way to light up the road, but would it change the answer to the OPs question?
Comment: P.S., And what if we take away the mask? What if we ignore the rays that go off into the darkness in all directions, and we only talk about rays that actually hit the distant pedestrian? Would that change the answer to the OPs question?
Comment: @SolomonSlow - to address your question, Vid's explanation describes how the flux density is changing from a point source. By adding optics to the system like a reflector to concentrate the light, we are changing the flux density in the direction of the observer, so that the apparent brightness of the original lamp is significantly higher for an observer.  So in your scenario, the apparent  brightness of the isotropic points source will be substantially lower (likely not seen at large distances) whereas the lamp with optics will be perceived as significantly bright as the OP observed.
Comment: P.S., I never was disagreeing with anything in your answer (which, by the way, I up-voted.) I was only saying that any talk about what the lenses and mirrors do is superfluous. _Any_ light source—even a giant star with a radius of a hundreds of millions of kilometers—looks like a point source if you stand far enough away from it. If you simplify a problem by pretending that a car headlight is a point source, that simplification won't substantially change your answer if the headlight is 100m down the road.
Comment: @SolomonSlow  i.e. A headlamp bulb (no optics) puts out ~1200 lumens.  The itensity traveling to the observer 100m away 1200/4pi = ~95 cd.  At a distance of 100m a lux meter will measure 0.0095 lux.  A lamp with optics will measure at 100m ~ 2.5 lux.  So to produce the equivalent brightness at 100m using only bulb, you need a flux of 333,000 lumens.  This will  illuminate the road to a much higher level and longer seeing distance than the headlamp (headlamp beam is narrow, point source is radiating all directions)  meaning that the ratio you proposed is not the same between the two.
Answer: You are seeing light that comes directly from the car headlights. In contrast, the driver is seeing light that comes from the car headlights and bounces off of you. First of all, you are pretty dull (physically, not personality-wise) and don't reflect a lot of light*. Second, the light has to travel twice as far to reach the driver's eyes**.
Edit:
*I think it's actually more important that you reflect light diffusely. If you were a mirror, and you were oriented so that you reflect light directly back to the car, then most of the light that reached you would reach the car. In contrast, since you're probably not a mirror, a lot of light is reflected in other directions, and only a bit of the light returns to the car.
**As commenters have mentioned, the intensity of light does not significantly fade with distance if the beam is narrow (as with a laser beam). This answer assumes that the car headlight does not produce a narrow beam of light, in which case the intensity of the light fades as $\frac{1}{r^2}$.
Comment: @BM The intensity (or illuminance or irradiance) of light or other linear waves radiating from a point source (energy per unit of area perpendicular to the source) is inversely proportional to the square of the distance from the source; so an object (of the same size) twice as far away, receives only one-quarter the energy (in the same time period). Per Wikipedia https://en.wikipedia.org/wiki/Inverse-square_law#Light_and_other_electromagnetic_radiation
Comment: The distance has nothing to do with the visibility of light as long as we assume there are no atmospheric effects. There might be, but I would point that out as separate scenario.
Comment: For narrow wave, the light doesn't faint with distance. You have to evaluate the power/distance relation.
Comment: A mirror would be brighter if it's perpendicular to the path to the car. On *average*, over all angles, it would be the same brightness.
Comment: You don't even need an adjusted mirror to become visible, reflector stripes on your clothes suffice. And they are an excellent example of how important the distinction between directed reflection and diffuse reflection actually is.
Comment: So, a quick-witted person wouldn't reflect more? :D
Answer: The headlights that you see appear to have a brightness at your position on the road that is large enough for you to detect them. For the driver to detect you, he has to make use of the light reflected off of you back in his direction. That amount of light is small because you are not very reflective (as @Ankit alludes to in his comment) - your clothing absorbs and scatters a lot of the light incident on it.
Comment: Albedo of any "normal" object is still quite low... So it reflects quite a lot of light... We are not all coated in venta-black or any special ekstra black color. You can observe phenomena from question even with a mirror
Comment: @Vid If something has a low albedo, that means it doesn't reflect much light.
Answer: There are two main reasons, as alluded to throughout the other answers:

Your eyes and the drivers eyes being open different amounts--due to having to calibrate with the amount of light in the environment in order to not over or underexpose the environment.
The amount of light coming from you vs. coming from the car.

In the case of 1, look at your pupils when in a very dark room, vs very bright room. You'll notice that in the dark room, they're much larger. Why is that? Well, there are less photons coming into contact with your eyes when its darker, so in order to maximize the light coming into your eyes, they open up more. In your scenario, the person standing on the dark road will have larger pupils than the person in the car, because they're calibrated to the dark environment with little light.
In the case of 2, you're less bright than the car. Even if your pupils and the drivers pupils were collecting the same amount of light, there's much more light coming from the car (which is producing light), than you (which are only visible due to reflected light).
Answer: I have never seen such a load of unnecessary verbage in answer to a question!
We see the light from stars millions of light years away from us but only a complete dum-dum would expect an observer on a planet orbiting a distant star to see that star's light reflected off say an astronaut doing an EVA in Earth orbit.
The answer is that there is simply not enough light reflecting back towards the source. It's as simple as that.
Answer: Strictly speaking the following statement is wrong:

the car will brighten the road only few hundred meters further

The fact that you can see the light emitted by the car is evidence for the light illuminating all the way between you and the car.
Two main reasons can be named why you see the car but the driver does not see you:

Scattering of light
The sensitivity of the human eye (and brain) for scattered light

The first effect leads to the car's light being scattered, the second to the driver not seeing this light.
Comment: Re, "sensitivity of the human eye...for scattered light." There's nothing special about scattered light. Your eye is no more sensitive to scattered light than it is to light coming directly from the headlights of an oncoming car. The reason those two situations are different is that the [_radiosity_](https://en.wikipedia.org/wiki/Radiosity_(radiometry)) of light leaving the headlamps of a car is several orders of magnitude greater than the radiosity of light that is reflected off of distant objects that are illuminated by the headlights.
Comment: @BM Yeah true, but light sources are generally isotropic rather than narrow, with exception of lasers.
Comment: "There's nothing special about scattered light". Yes there is: it has less radiant flux, since scattered. :-) But you put that into more precise terms and I agree with your explanation. Bottom line is: if you put a perfect mirror next to the observer and assume the car's light travels in a perfectly straight line, the driver and the observer would see the light the same way.


Are specific questions on linux-based certification material appropriate here?

Question: I'm studying for the LPIC-1 exam and would like to ask specific questions regarding some course material that doesn't make sense.  Is it appropriate to ask those questions here?
Answer: If the course material is about Linux, and if you're not violating any copyright or confidentiality agreement you've signed, sure.
Comment: Absolutely.  Just to be clear, this wouldn't be "homework" questions or any sort of braindump stuff.  I'd just like a place to ask linux-based questions if the author doesn't describe concepts in a way that makes sense to me.  Thanks.


Creatine supplementation for a Vegan athlete

Question: Any thoughts on creatine supplementation (quick release capsules 4,000 mg) for weightlifting? I caveat this request with the fact that I am trying to limit my intake of animal products to a minimum and rely on plant-based protein sources. There is a fair amount of research in the public domain about creatine deficiencies in vegetarians although some say the human body can produce all it needs. Is oversupplementation a potential danger? Thanks.
Answer: 3-5 grams of creatine per day (1 of your pills) is generally considered a safe amount. There has been evidence of liver/kidney damage as a result of taking too much Creatine, but seems to only be the case with people who already have kidney/liver problems. Studies have shown that as much as 20 grams of creatine per day is safe.
The only real downside is water retention (i.e., bloating). Taking a lot of creatine will cause an average person to gain around 5 lbs in water-weight (which will only go away when you stop taking creatine).
Humans typically get half of their Creatine from meat, specifically red meat, so it's definitely more important for vegetarians. You may choose to do an initial "loading phase" where you take 2-3 of those pills per day for 1-2 weeks to build up your initial stores. Then you can maintain your Creatine stores on 1 of those pills per day.
On the flipside, you may want to consider doing your maintenance on only half a pill per day. 2 grams is shown to still be effective, while minimizing water retention. A lot of bodybuilders choose to "cycle" their Creatine. They may only use it for a month, and then not use it again for 2 months. They use it professionally as a supplement for beating personal plateaus. But whether you want to cycle it or use it daily is up to you.
Comment: It's also one of the more well studied and researched supplements with clear performance gains and minimal risk. It's also cheap.
Answer: I am just going to straight up copy the pertinant information from examine.com's site on Creatine which has links to hundres of studies and breaks down exactly the benefits of creatine.
But the answer is:
Creatine is safe, but just buy the cheapest form you can find.
Any thoughts on creatine supplementation (quick release capsules 4,000 mg) for weightlifting?

I honestly see no reason why somebody shouldn't supplement creatine, nor do I see any logical basis for the seeming 'fear' of this compound in society.
    It's safe, it's healthy, it's cheap, and for most people, it just works. Get some Creatine Monohydrate, take 5g a day, and you're good to go.
    If humans didn't make any in the body, this thing would be a vitamin.
-Kurtis Frank

Is oversupplementation a potential danger?

Creatine is one of the most thoroughly researched compounds, and no adverse side effects have been noted through supplementation.
From Is creatine safe?
Side effects of creatine include stomach cramping, which can occur if creatine is supplemented with insufficient water, and diarrhea, if too much creatine is supplemented at once.

Are quick release capsules better than anything else?

The best form of creatine is basic Creatine Monohydrate, which is the cheapest, yet on par with many other forms. No other form has enough evidence to claim it is better than Monohydrate.
From What is the best form of creatine?


Why was the North willing to go to war over Slavery?

Question: [edited]
According to Washington Post, "There is a consensus among historians that the root cause of the Civil War was slavery". Assuming that slavery was indeed the root cause, I can understand why the South would be willing to go to war to maintain it: because their economy depended on it to a very considerable degree. But why would the North care so deeply about this issue as to allow tensions to escalate into a war? I imagine abolition would indirectly hurt them economically as well, and it does not seem likely that their objections were purely moral in nature, if racist laws remained in force for a long time after the War. Or is it not the case that slavery was the root cause?
Comment: 1) You can be racist and still against slavery. 2) Why do you think abolition would hurt the North economically? 3) Many in the North *did* want to avoid a war over slavery; once the South rebelled, it became fighting to preserve the union.
Comment: Finally questions about slavery are provocative; they frequently lead to more argument than edification.  Questions about provocative topics have to meet a higher standard to ensure that we'll get answers, not arguments.
Comment: Twice people have asked for sources.  Please provide sources.  Quite simply sources are the difference between a historical discussion and a pub argument.  We're not interested in pub arguments.  I understand that you don't think the sources make a difference.  But the reason we keep asking is that we think they do make a difference. Humor us.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](http://chat.stackexchange.com/rooms/71114/discussion-on-question-by-kamil-s-why-was-the-north-willing-to-go-to-war-over-s).
Answer: I'm going to have to provide a bad answer because the question is ill focused, lacks evidence of research, and OP persists in debating in the comments rather than revising the question to resolve the issues about which comments have requested clarification.
The question seems to be an attempt to identify the role of American chattel slavery as a cause of the civil war. It contains the assumption that the North was responsible for pushing the South to war.

There are very few things in history that have a simple cause and effect relationship. (or perhaps there are, but we don't study them because they are trivial.)  Slavery was a cause of the war.  Fundamental tensions originating before the Constitution was a second cause of the war.  Cultural divergence was a cause of the war.
The North didn't start the war; the South did.  The South started the war because they didn't believe that the country could encompass the visions of both the South and the North, and because they believed that a non-military strategy would result in unacceptable losses for the South.  They believed that the North wanted to eradicate the Southern way of life.  The symbol of this was slavery, but their concerns were broader - there were irreconcilable economic and cultural differences - the 3/5 clause in the constitution, the Jay treaty, etc. etc. etc.  The North sought a future for the country that included both freedom from slavery and prosperity. The North had made that clear from the foundation of the Republic.
The Southern political position was idiotic.  The South sought a future based on a fantasy recollection of medieval life.  Their vision was utterly unconnected from reality, and their economic principles were less sophisticated than your average third grader.  They wanted to get rich by selling commodities in an unchanging world. They rejected industry, credit, capitalism, and every vestige of modernism.  They created a fantasy reality based on a bygone era where land was more important than capital. They held dances and wore fancy clothes and each generation was financially, intellectually and morally inferior to the last.
It is not possible to predict a person's view based solely on their economic class/interest  By the middle of the 19th century there was a consensus that abolition and civil rights were the right choice even if that choice involved some economic hardship.  Britain endured huge economic hardship to fight slavery on a global scale.  The New York Abolition society had existed since the beginning of the Republic.   For some people, civil rights were a religious imperative; for others an ethical or moral imperative that trumped their economic self-interest.  The South rejected this consensus, slowly transforming from irrational to delusional to pathological zealotry. In the end they started what was the bloodiest war in human history to that point in order to silence the people who kept demonstrating that the Southern way of life was delusional, disconnected from reality, immoral, and economically stupid.

Was slavery a contributing factor to the civil war? Yes.  But slavery was one element in a mix of tightly coupled factors that ultimately resulted in irreconcilable differences.
Unfortunately a full answer to the question would be more than book length - there have been multiple books on the causes of the civil war, more books on slavery, more books on the causes of war.  Questions that require book length answers are out of scope for H:SE (See [help]).  This is a bad answer because it includes no sources, no evidence of research, and has a few paragraphs of thought about a subject where an encyclopedia would be more appropriate.
Comment: I'm sorry if this is nitpicking, but for some reason one of your statements annoyed me. "they started what was the bloodiest war in human history to that point" seems to be contradicted by the Wikipedia article [listing wars by death toll](https://en.wikipedia.org/wiki/List_of_wars_by_death_toll).
Comment: Thank you. This is pretty much the answer I was looking for, just let me make sure I got it right. The War was primarily over the economic model of the South which the North could not accept, and the South would not give up; slavery was central to this model, but saying that it was in itself the root cause of the war is an oversimplification to the point of being wrong. Is this correct?
Comment: I don't think your answer is a bad one for any of the reasons you mentioned. I don't need sources because if your answer seems reasonable, I assume I can trust your expertise; I don't need evidence of research because your very answer shows if you know what you're talking about (i.e. if you've done your research in the past), and I don't need an in-depth, book-length answer, just a summary of the main points. I don't need any of those things because I'm just an interested layman, not a historian who's trying to research his or her paper through an on-line forum.
Answer: You are confusing two questions:
What was the root cause of the Civil War?
And
Why was the North going to the war?

North was not going to the war over slavery.

a. Before the war, already northern-dominated (after southern states seceded) Congress passed the amendment protected slavery:
https://en.wikipedia.org/wiki/Corwin_Amendment
b. Already during the war, Lincoln issued preliminary emancipation proclamation, practically stating that if southern states would stop fighting and return to the Union by 1863, slavery would be intact:
http://www.13thmass.org/1862/emancipation.html
North was going to the war to suppress an armed rebellion - Confederacy was already building army (up to 100 thousands strong, with US army at that time about 16 thousands), and attacked US army installations.

However, slavery definitely was the root cause of the war - if not single, at least by far most important.

Seven southern states seceded from US, because they demanded from federal government unlimited extension and protection of slavery beyond the borders of slaveholding states, and recently elected president (Lincoln) belonged to the party with main goal to contain slavery were it is already exists. Everybody understood that containing slavery would lead to its ultimate extinction.
So if not slavery, no secession and no war would occur.

It is tempting to say that South was going to the war over slavery. The answer is not so simple.

Sure, South was willing to go to the war over slavery, but it was no need over slavery - because North did not attack slavery when South started the war.
In my opinion, Confederacy started the war, because peace perspective were very bleak.
Seven cotton states practically did not have industry, adequate merchant fleet, financial institutions, and even adequate food and mule production; they were dependent on other states on almost everything. They practically have only cotton to export, it is why Confederate constitution removed the ban on taxing exports. Two cotton-producing states (Arkansas and Tennessee), being in northern Union, would compete with Confederacy cotton production on favorable terms. Pre-war Confederacy have dangerously high proportion of slaves, and lost Fugitive slave laws protection.
Secessionist counted on most slaveholding states to join them; it did not happened peacefully. On April 4th 1861, Virginia secession convention voted against secession, and a three-man delegation was sent to consult with Lincoln, who prior inauguration publicly discussed with virginian Fort Sumter evacuation in exchange of Virginia stays in the Union.
The only way to bring Virginia and other slaveholding states to Confederacy was the immediate war, and the war came - April 12 confederates bombarded fort Sumter. In a few weeks Virginia, Tennessee, Arkansas and North Carolina were joining Confederacy, increasing her white population twice and industrial and military strength much more.


Gear selector hard shifting gears

Question: I have a 2006 YZ250F, and whenever I go to shift gears while riding sometimes I really have to kick it hard. Sometimes even twice cause the first one didn't do it. I fiddled with my clutch lever cable a bit but not much of a difference. Sometimes when it's cold if I hold the clutch all the way in, and put it in gear, it immediately stalls. Is my clutch lever still just out of rig or do I have a bigger problem with the actual clutch disk?
Comment: Welcome to Motor Vehicle Maintenance & Repair! I think you've got the problem with the clutch adjustment. Continue to adjust it and see if it makes a difference. Also, make sure you're adjusting it the right way (IE: taking up slack and not giving it more).
Answer: Your clutch lever probably isn't adjusted right. The symptoms you described lead me to think your clutch isn't fully engaged when you pull in the lever all the way. Try to adjust it so the clutch engages earlier in the pull (So farther away from the handlebar).

Gear selector hard shifting gears


How can I predict the true label for data with incomplete features based on the trained model with data with more features?

Question: Suppose I have a model that was trained with a dataset that contains the features (f1, f2, f3, f4, f5, f6). However, my test dataset does not contain all features of the training dataset, but only (f1, f2, f3). How can I predict the true label of the entries of this test dataset without all features?
Answer: Assuming that you have access to the training data set, you could use an autoencoder network to predict what features f4, f5, f6 'could be' for the test data set. The way to do this is to train the autoencoder on the training data set with features f1, f2, f3 as inputs, and then use f1,f2,f3,f4,f5,f6 as the output of the network. The autoencoder then effectively learns to map any input samples with (f1,f2,f3) to (f1,f2,f3,f4,f5,f6). By passing your test data through the autoencoder, you can then use the output and pass it to your model.
Comment: Thank you so much! I will attempt to learn this network model
Answer: I assume you trained your model on (f1, f2, f3, f4, f5, f6) and in your test data you sometimes have (f1, f2, f3) and sometimes have for example (f1, f2, f3, f4, f5, f6), right? Because if your test data always have (f1, f2, f3), then isn't it better to just train a model on available features?
So if my assumption is correct what I would do is to manipulate the training set a bit, keeping some training set with (f1, f2, f3, f4, f5, f6) and some others with (f1, f2, f3) with replacement of real values in their (f4, f5, f6) by e.g. mean of respective feature. So all training set still have (f1, f2, f3, f4, f5, f6) but some of them have manipulated (f4, f5, f6). Then finally when testing, do the same manipulation to those test data that have a smaller number of features.
I think like this your model learn how to predict base on (f1, f2, f3) when other features are not available. but at the same time, take advantage of all features if they are all available.
It's probably not the best approach but it worth to try.
Comment: Um.. Thank you so much for your explanation
Comment: I think your explanation means 'imputation' for missing value


How to inform user that value of form field was removed?

Question: We have some background processing on form and in the result, some of the form fields can become null.
So how should information message about this action look like?
The best option we have "The value of X was set to blank".
Comment: Can you show us a visual mock of your efforts and the surrounding context? What's the domain, who are the users? Do they understand technical terms? Where does this message show up? is it outside the form? The more context, the better the available answers tend to be, and the more the question is valuable to others.
Comment: Why would they become null or empty?
Comment: What do you mean by "null"? The default option or zero?
Comment: Are you suggesting a dependent field like City to Country? Hopefully the null values do not appear in too many fields. You can highlight and maintain focus on the appropriate field or section to suggest that it needs user attention. A message may not be necessary. If needed a contextual message on the side of the field can be added.
Answer: If I am understanding your question, there are some fields on your form that when information is entered, override some other fields that are no longer needed (for example, use saved phone number vs. enter a new one)

First the field should be disabled (visually, that is usually achieved by reducing opacity or graying out)

Second if the user has already entered input, you probably do not want to clear the value from the disabled field and instead just ignore that field when submitting.
That way if the user were to change their mind, they could go back and continue editing the field without having to type everything all over again.
Answer: If I understand your question correctly, you have a form with a set of fields and on saving the form, you are processing it in a way that one or more fields are set to a NULL value.
It would be interesting to know why you want to set the values to NULL in the first place. But I can see a couple of possibilities here.
If you are setting blank fields or the fields which the users haven't filled to NULL - you can have a field placeholder text that can say something like for e.g. - Enter a value (Default NULL)
If you are overriding the user input to NULL - I don't believe it's a good practice. If the entered value is invalid, you can always validate and highlight the field. But there's no reason to override a valid user input, you can just avoid the field instead.


What chessboard companies are the most reputable?

Question: As a follow up to my original question What are the characteristics of a good chess board? I was wondering what companies are the most reputable for chessboard construction. Since I am just a beginner I am curious at lower cost beginner boards, but also in other boards that I might want to splurge on one day if I really get into chess.
Comment: I'm not sure that's a massive distinction.
Comment: This sounds a lot like a request for shopping recommendations.
Comment: @DavidRicherby The emphasis is on companies, not products
Answer: The standard vinyl board is hard to beat for everything except showing off a chess set.  You can get them for cheap from the USCF or from any other purveyor of chess gear.
Here's one from Cajun chess for $4.  I bought a few sets from them. I like them.
Looks like tournament-sized wooden boards begin at $50.
Answer: I don't really know any cheap chess board companies, but checking out websites like
The Chess House can yield very good results.
For a nice splurge, the best boards are without a doubt the DGT ones,
Answer: Most reputed brand in Chess boards is probably Staunton. They are manufactured by
Jacques of London and have been in circulation since 1849!
Answer: DGT chessboards are the best. The digital chessboards are definitely helpful in your chess career, besides, the quality is really good; the only downside is that it is quite expensive. However, I would say the board is worth the price.
Answer: The most reputable chessboard company I know is chessbazaar.com. They are the finest crafters of chess pieces and boards and they do it at the lowest price in the industry. the quality is not compromised.
Comment: Welcome to [chess.se]! Are you affiliated with this company? If so, you need to [explicitly state so](/help/promotion).
Comment: no! I just bought some products from them which I felt are good for users to try.
Answer: UK and Europe based can order chess board from Discover Handicrafts
Their chess boards are made from wood and very artistics.
Answer: "Caveat Emptor"
A lot of the chess sets out there look pretty nice, but frankly most of the manufacturers invest all their effort into attractive molds and durable plastic.  Very few of them offer even the most basic features that you would expect in this day and age - the features that would most enhance your game.
I just spent over $50 for a tournament set for my son.  Yes, it has hefty, triple-weighted pieces for stability and an attractive Staunton design, and the pieces seem very durable.  The set even came with extra queens - a nice touch for those four-queen positions you get every once in a while.  But look at what it doesn't have:

Undo.  This feature has been in cheap word processors since the '80's, but is totally missing from the set.
Syntax Checking.  The set allows illegal moves without so much as a warning. This has been a feature of programming editors since the '90s.
Speed Regulation.  The set allows me to make moves as hastily as I want, even though my game always suffers as a result.  For goodness sake, the escapement has been a part of clocks since the 13th Century!
Drink Holders.  Ok, this one is just a personal preference, but my minivan comes with about 16.  You would think that a chess set would have space for at least two.

The upshot:  It doesn't seem to matter how much you spend, you aren't going to get these sorts of features.  So if you ask me, all the companies out there are ripping us off.  The USCF has been doing it the longest - I suppose there is some merit to the thought that if you are going to be swindled, get swindled by someone who has been at it for a long time and has swindled lots of others.  It's less embarrassing.
Comment: @Laska  Don't fret.  I'm still here.  And for me, only one downvote is like a +1.  I have two kids, so all my jokes at home are guaranteed at least two downvotes.  Three if the wife is in the room.
Comment: I know this is somewhat of a frivolous answer, but I think well-written humour has a place in this site to complement the more serious answers which are often of necessity rather dry. It enriches our stackexchange culture. "It's only a game" after all. However the only reaction this received was a single downvote! That amazes me. And where is poor pokep now? Not here, that's for sure!
Comment: Hurray glad you are still here more answers please (although I can't promise to downvote you :-)


Naming for a REST webservice

Question: I have a rest webservice with an endpoint www.foobar.com/service.svc/MAC  (migration authorisation code). Posting and getting to that adds and gets one MAC respectively. I now need to impliment a new enpoint for all MACs. What would that be? www.foobar.com/service.svc/MAC/All seems wrong. What would be correct and why?
Answer: Here's what REST usually looks like
GET www.example.com/service.svc/MAC - gets a list of all the MACs
GET www.example.com/service.svc/MAC?{property}={value} - search MACs by specified properties
POST www.example.com/service.svc/MAC - creates a new MAC
GET www.example.com/service.svc/MAC/{id} - gets the MAC with the specified id
PUT www.example.com/service.svc/MAC/{id} - updates the MAC with the specified id
DELETE www.example.com/service.svc/MAC/{id} - deletes the MAC with the specified id

There are a few less used operations as well: PUT /MAC would replace the entire collection of MACs, DELETE /MAC would delete everything, and POST /MAC/{id} would create subitems in the MAC, but it looks like you won't be needing those.
Comment: Also notice that as a response to "POST www.example.com/service.svc/MAC" the server should return 201 plus Location header for the newly created resource, if successful.
Comment: @configurator isn't post supposed to be update and put supposed to create the MAC ?
Comment: @vikkyhacks that's what I used to think but I eventually found out I had been mistaken.
Answer: The following offers a suggested set of URI naming guidelines for REST services that have worked for me in practice.

The book RESTful Web Services RESTful Web Services defines three basic rules for url design which act as a great starting point:

Use path variables to encode hierarchy: /parent/child
Put punctuation characters in path variables to avoid implying hierarchy where none exists: /parent/child1;child2
Use query variables to imply inputs into an algorithm, for example: /search?q=jellyfish&start=20

 Other guidelines include:

URIs should ideally not change over time.
Services offering a uniquely identifiable resource via a key should use basic rest notation (e.g. /accounts/(accountid) )
Services offering optional search/filtering capabilities should use query parameter ? key1 = value & key2 = value notation (e.g. /instruments?ticker=FT)
Services expecting mandatory arguments over GET should have them as path variables (e.g. /accounthistory/(fromdate)/(todate)
All rest service names should use strict low case names (e.g. /client)
The elements of the URI should map to business entities and the mapping should be consistent. For example a business entity named contentpartner should be consistently referred to as contentpartner(s) in all URIs (rather than a mix of partner, cp etc).  A good starting point would be the name of the domain object.
Parameters that do not define a resource but qualify it (e.g. locale which feeds into the translations of the data) should not form part of the normal URI space.  Consider using headers or optional query parameters for these
Use nouns, not verbs.  The power of REST comes through the fact there is a limited verb set (operations) combined with a large set of nouns (or resources). Consequently the manner in which these nouns are constructed is of great importance.
Avoid suffixes.  When designingURIs it is paramount that they refer to the thing that is being operated upon rather than the operation being performed. Secondly, the client is interested in the resource - not the implementation of the server software that powers the service. It is desirable to avoid suffixes such as .jsp or .aspx.
Use Accepts Header for content negotiation
Keep It Intuitive. URIs should be human readable or guessable. The easiest way to do this is to construct a URI hierarchy, grouping related items together. Such patterns of category and subcategory are very easy to understand.
Answer: RESTful way for listing all MACs is:
GET www.foobar.com/service.svc/MAC

Why? Well, because it's a convention and people expect REST service to behave that way.
If you want to read more on that topic, check out how RESTful routing is done in Rails.
Answer: I posted a series of guidelines here: http://soaprobe.blogspot.co.uk/2012/10/soa-rest-service-naming-guideline.html
These are being used effectively,  where I work.
UPDATE - I pasted the contents into another answer....
Robert
Comment: Hello @Robert! Answers that are link-only aren't very good, since if the link rots, your answer won't mean anything. Maybe you could add the general guidelines you specify in your blog here?
Comment: You could have edited this question instead. Would be good to delete this one now.

Naming for a REST webservice