Death according to various schools of buddism

Question: How is death perceived in various schools of Buddhism? Are they all same ? What is death according to Buddhist monk and lay Buddhist? Are there references / materials by monks on death bed about death?
Answer: In the ancient Pali scriptures, the word 'death' has two meanings: (i) conventional; & (ii) ultimate. In the language of ultimate truth, 'death' refers to the psychological idea that "I" or a "person" or a "being" ("satta") dies (SN 12.2).
The Buddha taught a 'self', 'person' or 'being' ('satta') is only a mental state of craving & attachment (SN 23.2); that in reality, there is no 'being' ('satta') to be found (SN 5.10).
'Death' only happens when there is unenlightened 'self-view'. This is why the Buddha called enlightened selfless nirvana: 'The Deathless'.

He has been stilled where the currents of construing do not flow.
  And when the currents of construing do not flow, he is said to be a
  sage at peace.' Thus was it said. With reference to what was it said?
  'I am' is a construing. 'I am this' is a construing. 'I shall be' is a
  construing. 'I shall not be'is a construing. Construing is a disease, construing
  is a cancer, construing is an arrow. By going beyond all construing,
  he is said to be a sage at peace.
A sage at peace is not born, does not age, does not die,
  is unagitated, and is free from longing. He has nothing whereby he
  would be born. Not being born, will he age? Not aging, will he die?
  Not dying, will he be agitated? Not being agitated, for what will he
  long? It was in reference to this that it was said, 'He has been
  stilled where the currents of construing do not flow. And when the
  currents of construing do not flow, he is said to be a sage at peace.'
Dhatu-vibhanga Sutta

In enlightenment, all that occurs at what is conventionally regarded as 'death' is the five aggregates come to an end, that is all.

Form is impermanent... Feeling... Perception... Fabrications...
  Consciousness is impermanent. That which is impermanent is
  unsatisfactory. That which is unsatisfactory has ceased and gone to
  its end.
Very good, my friend Yamaka, very good.
Yamaka Sutta
Answer: My rep not enough for comment, So this is not an good answer because I've no reference for you.
Everything that have soul are the same. Animals, people, human, monk, angel etc.
However, The basic precept for every human to close the hell was 5 percepts because these percept make you not exploit other's and your's life.
But for monk there where 227 percepts, This make lay buddhist and others can worship them.
Monk are so much much bigger chance to go to hell. But also much bigger merit for him if he was good.
Answer: There's no death.
Beings wander from life to life.
By experience they learn.
By knowledge they destine themselves to future lives.
Until enough knowledge is attained.
Wander no more.
Answer: All life is suffering. The transition to death is an escape from the sufferings we bear when we are in life. This is the teachings which the Buddha made about life and we should not have any attachments to this. There are many precepts which teach about these things and death comes when we have had enough experience.
Comment: You might know this already, but I'll mention it in case it's helpful.

I wonder if "All life is suffering" is a misunderstanding of "All conditioned phenomena are unsatisfactory (dukkha)". That only means that nothing gives a *lasting* satisfaction, they change and stop being satisfactory.

The "escape from suffering" is not death. Death only leads to another life. The end of suffering is full enlightenment (Arahant) and is Nibbana.

Hope to keep seeing you around here.


Introductory biology text for an outsider

Question: I'm a maths major and I have an interest in learning biology. I know very, very little; I know how babies are made and that's about it. Could anyone recommend a stimulating text to read for its own sake and also to use to learn biology?
Comment: What aspect of biology do you wish to learn? (Human biology, plant biology or Zoology? I'm guessing you are interested in human biology from your e-mail). For example are you looking to explore mathematical applications within biology?-e.g. mathematical biology or you just want to study biology in your leisure.
Comment: I'm being deliberately vague here; I just want very basic biology and not specific at all. I am deliberately NOT looking for a mathematical perspective, however I would like a generally insightful and interesting view on the topic.
Comment: I think Helena Curtis Biology is a quite interesting book. It was written many years ago and so does not involve really recent research but it is really insightful. Another book I would recommend is Campbell - it is both recently written and thought provoking. You should also read magazines like Scientific American to get insight into latest happenings.
Answer: I found the Campbell Biology textbook to be quite comprehensive and approachable. I think many introductory biology courses use it.
http://www.amazon.com/Campbell-Biology-Edition-Jane-Reece/dp/0321558235
Comment: Yes.  This one. By the time I graduated, I think I had 4 editions.
Answer: There are tons of books and it is quite hard to find one that gives such a broad overview. Campbell Biology is a book that basically covered the first year of my Bachelor degree in biology. I am not sure it would be very stimulating though! If there is a specific branch of biology that interests you, let us know we'll be able to give you a better advice.
As a math Major you might enjoy some fields of biology that are highly mathematized. For example, system biology or theoretical evolutionary biology. For the latter, you might like to read Evolutionary Dynamics: Exploring the Equations of Life book from Martin Nowak. But I am afraid it might not be a nice idea to directly jump into some specific subject before having a good overview of the life sciences.
Otherwise you might appreciate some books of popular (but good level) science such as the Extended Phenotype from Richard Dawkins. This book is very stimulating and I think it starts with some basic definitions of biological concepts such those of "alleles" or "phenotype".
I gave you two examples of books from the field of theoretical evolutionary biology. For more recommendations in this field, please have a look at Books on population or evolutionary genetics?.
Hope this helps a bit!
Comment: Could you list the book title that you linked to?  The link is now dead but I'd be interested in checking out the book.
Comment: @Addem Thanks for highlighting my broken links. It was a link for the Campbell. The same one as suggested in xuanji's answer. See edit.
Answer: You should check out Richard Dawkins' book The Greatest Show on Earth: The Evidence for Evolution
It does focus heavily on evolution but it is an amazing book on biology in general.  He covers a wide rage of other topics, from how birds flock so elegantly to dating fossils using dendrochronology.  The chapter on embryology is fascinating.
Answer: @xuanji offers a good choice with Campbell Biology  if you want a text solid biology textbook. I've got a copy in my library. I would suggest buying a previous edition if you're trying to save money. However, the book could be a bit dry. Reading semi-popular books on topics you are interested about would probably be better approach.
Both @ebrohman and @Remi.b provide good suggestions with Dawkins. I also like Ernst Mayr's What is evolution on the topic of evolution.
For ecology, check out books by E.O. Wilson or Jared Diamond.
If you want to learn more about environmental toxicology, Rachel Carson's Silent Spring is a good book to start off with.
If you're looking for a mathematical biology book, Linda Allen has two biomath text books, one on deterministic models the other on stochastic models. Murry's also produced some classical mathematical biology books. Most people would consider these books dry, but as a mathematician, you might like them.
James Watson can be controversial but he's written some interesting books. His Double Helix is a good read.
If you provide what specific type of biology and mathematics you are interested in, I will provide more suggestions.
Answer: The Bible of biology is the Alberts' Molecular Biology of the Cell:

http://www.ncbi.nlm.nih.gov/books/NBK21054/

The Campbell is also pretty good and maybe easier to read..
Comment: Campell would provide a better overview if the OP wants to learn about more than molecular biology.


Hudson kills the process at end of the shell script

Question: Im configuring Hudson to automate deployment process. In shell script I start the server using different user and Im able to see the logs which says server is successfully started and able to access the application. But Once Hudson reaches end of the script the process killed.
When I check process details, till the shell script complete, the process alive. Once the shell script is complete the process is not there.
Can you please help me how to keep the process alive even after shell script execution is completed by Hudson
Resolved by the trick mentioned in https://stackoverflow.com/questions/5728899/tomcat-script-not-working-when-run-from-hudson
Comment: Resolved by the trick mentioned in http://stackoverflow.com/questions/5728899/tomcat-script-not-working-when-run-from-hudson
Answer: Can you provide the script?
Have you tried simply appending & to the server start command to background it?
Comment: Thanks !!! I tried with nohup but no luck, Resolved this issue by solution given in http://stackoverflow.com/questions/5728899/tomcat-script-not-working-when-run-from-hudson


Is there any engineering proof to which type of memory card is more reliable

Question: Between a SD card and a Compact Flash card for using in camera, which I write RAW images of 40 mega byes on it, sometimes in burst mode and never for video, Is there any technical reason to favor SD cards in general to Compact Flash cards for "Reliability" and vise vera.
I understood that it depends on Manufacturer, etc.. imagine the best SD card of SanDisk vs their own best CF card! I mean actually comparing the electronics of a SD card vs a CF card to know which one I should trust for reliability.
Answer: In general the top tier Compact Flash cards available to the typical consumer via retail channels when compared to the top tier Secure Digital cards available to the typical consumer via retail channels are:

More rigid and less susceptible to damage from flexing
Rated for more extreme environmental conditions (higher altitude, lower temperature, etc.)
Have faster write speeds (although this gap has been narrowing recently), even when read speeds are the same or very similar
More expensive

Additionally, CF cards use the standard IDE protocol to communicate with other devices. SD cards use their own protocol that has been modified/extended several times (e.g. SD → SDHC → SDXC → UHS → SDIO). Device compatibility with SD cards newer than the device can be an issue. Newer, faster CF cards tend to be more backwards compatible with older devices, albeit at the older device's speed rating.
SD cards only have enough connectors to move between one bit (original SD standard) and 8 bits/one byte at a time (only the fastest, most advanced UHS-I or higher cards). CF cards have 50 connector pins and enable multi byte parallel write or read at the same time. Your camera must support multiple port parallel write to take advantage of this difference.
On the other hand, the pins on devices that use CF cards can be bent while the connection between SD cards and their compatible devices are less susceptible to damage from card insertion and removal.

Appendix (probably obsolete by the time it is typed)
Current fastest transfer rates as of August 24, 2015 as specified and available on amazon.com
SD cards: SanDisk-Extreme-UHS-I-Memory-SDSDXPA-032G-AFFP    Capacity: 32GB  Protocol:SDHC I, Class 10, U3  Speed: Up to 95MB/s    Cost: $29.95
CF Cards: SanDisk-Extreme-CompactFlash-Memory-SDCFXPS-032G-X46    Capacity: 32GB    Protocol: UDMA-7, VPG 65    Speed: Up to 160MB/s    Cost: $59.95
Comment: 1 bit SD (or actually MMC) was true long time ago, it is 4 bits now since 2006 (SDHC, SDXC)
Comment: Did you mean to write that SD cards move one *bit* at a time, not byte?  CF cards can move up to 16-bits (2-bytes) at once but have to run to a much (much) slower clock.
Comment: Re: current SD cards: Double data rate operation at 50 MHz (DDR50) is also specified in Version 3.01, and is mandatory for microSDHC and microSDXC cards labeled as UHS-I. In this mode, four bits are transferred when the clock signal rises and another four bits when it falls, transferring an entire byte on each full clock cycle.
Comment: @szulat - could quibble over semantics but it's not going to help clarify the answer, SD Specs before v4.0 (UHS-II) have one physical data line so it's still one bit at a time, just modulated faster.  UHS-II has 4 data lines and in the case of the [SanDisk SDSDXPB-016G-G46 Extreme PRO](http://www.amazon.co.uk/SanDisk-SDSDXPB-016G-G46-Extreme-UHS-II-Memory/dp/B00IITQA04) a read speed of 280MB/s.  CFast (if we're going there) is even quicker if memory serves.  Not quite sure that it addresses anything to do with reliability though.  :)
Comment: Hmm. That card is not available via amazon in the U.S.
Answer: All flash memory systems have their physical enclosure and 2 electronic systems - a controller and flash memory to determine reliability.
Electronics
Electronically there is no discernible difference because the storage side of flash memory (NAND) is the same across all the types (CF, SD, etc.)  NAND at the chip level has a serial interface and relies on controllers to make it usable, manufacturer implementations differ but the principle has remained the same since it was invented in the 80's.
Making 100% reliable NAND is commercially impossible, so between the flash chip(s) and the device (camera etc.) we have to have an interface.  Electronically this interface is a single point of failure on all form factors - provided your connection is electronically compatible (it sends the right signals) then again the controllers are implemented in silicon and are equally reliable.
As far as data reliability goes, any differences are purely down to production quality and how the manufacturer has implemented the workarounds you need for NAND like wear-levelling, error correction, and bad block detection/marking in the interface.
Packaging
The physical form factor is really a toss-up between pins vs. edge connectors.
CF's greater size does allow for more physical protection and rigidity but this could be addressed in the materials of SD cards if there were demand for it.  Industrial SD cards rated to handle operating temperatures of -40 to 85 Celsius which would outdo most cameras are available.  Properly secured both are able to withstand shock loads beyond most cameras.
CF has more pins which could improve it's performance under vibration loads but the majority of the pins are throwbacks to having controllers outside the device and the additional data lines (8/16-bits vs. 1-bit) offers no additional resilience.
I have seen casings on SD cards fail due to poor materials but this hasn't been the design of the interface at fault - the cards tend to still work long enough for data to be recovered and they are less likely to damage delicate pins in the host.
Anecdotally, where SD casings have failed on me the data was still accessible - CF cards I've not been so lucky.
TL;DR
Electronically there's nothing in it.  Knowing quite a few ham-fisted types I tend to favour SD's edge connectors as being more robust.  But you'd be better off getting whatever body offers the features you want and not worrying about media reliability.


How does the Stellar protocol ensure a network doesn't have disjoint quorums?

Question: Does Stellar maintain a set of nodes to achieve quorum intersection? If not, how can a Stellar network achieve quorum intersection at all times, meaning no disjoint quorums at all in the network?
Answer: Yes.  Stellar Development Foundation (SDF) maintains three validators, which you can find in this list of validators.  If you include at least one of them in every quorum slice, you will stay in sync with SDF and hence very likely with the rest of the world.
Down the line, however, other entities may come to be perceived as more important than SDF (e.g., maybe IBM), in which case you should add those entities as well.  The configuration format is hierarchical, so you can require, for instance, one SDF node and one IBM node in every quorum slice.  If there is an exchange or token that you rely on, then you should also include the exchange or token issuer if they have validators.


Is it safe to drink reboiled water?

Question: There have been some claims saying that drinking reboiled water is dangerous because it produces arsenic, nitrates, etc. Is this true?
Comment: Drinking boiling water is a bad idea in general - you'll burn your mouth!  Wait for it to cool first and you should be fine.
Comment: The claims are not true, they are just rubbish pseudoscience misinformation. Google "reboiled water" and skip the websites that claim to be "natural" "healthy" "chemical-free" etc. Those people don't know what they're talking about but just like to fear monger.
Comment: Boiling water produces arsenic, nitrates, etc?   Can it produce gold?
Comment: A different concern in reboiling water is that the water has been degassed. Such water can "bump" rather violently when it starts to boil.
Comment: @Paparazzi: sure, about 1 microgram of gold per kilogram of seawater apparently.
Comment: Some [interesting comments here](https://www.physicsforums.com/threads/is-it-bad-to-reboil-water.295974/)
Comment: I've found an additional leg of the claim, namely that "High temperatures transform nitrates to nitrosamines" (http://www.whydontyoutrythis.com/2015/06/warning-why-you-should-never-reboil-water-again.html). Which is technically true, but this is a potential issue when *cooking food*, and especially at frying temperatures. Not so much when briefly boiling water that contains only trace amines to start with. If you cook your food then (re-)boiling water is nothing by comparison.
Comment: @SteveJessop But I would say the gold was not *produced*.  The gold was there - just increased the concentration by boiling off the volatile components.
Comment: See http://skeptics.stackexchange.com/q/11118/8755
Comment: It is safe but if you have the option to use fresh water that will taste better. I empty my kettle each morning and refresh the water. The more the same pot is boiled, the less aerated it becomes, which impacts the brewing and taste, but not the safety. You saw that video of the plant being watered with (chilled) boiled water, I'm guessing.
Answer: Reboiling water will do precisely three things:

Some volatile contaminants in the water that survived the first boiling might be driven out by the second boiling.
Some additional evaporation will occur, causing anything dissolved in the water (salts, contaminants) to be slightly more concentrated.
Some additional material from the surface of the vessel you're boiling the water in might dissolve into the water.

It's virtually impossible to imagine any scenario in which this would matter, unless you were taking a huge amount of barely drinkable water and boiling away most of it or using a vessel whose lining could produce toxins in your water. Needless to say, you really shouldn't be drinking barely drinkable water at all, nor should you be boiling water even once in a vessel whose lining can produce toxins. If you're doing these kinds of things, the additional risk from reboiling would be miniscule.
It will definitely not summon aresenic or lead from nowhere.
Comment: I used to go camping a lot, and often times we boiled water to make it safe to drink. In many cases, we would "re-boil" the water because it was easier to do that then keep track of (or separate) "good" water from "bad" water.  #2 is your "largest risk" and to be honest, you would have to boil down hundreds of gallons of "bad" water to a few ml worth to be at any kind of risk. That being said, boiling water is usually done to remove bacteria, it won't remove dissolved things (like lead). So don't go drinking a contaminated water, regardless of the number of boilings.
Comment: @coteyr and if you were that worried about it, get a distilling apparatus! You might lose some minerals, but it doesn't get much safer!
Comment: @Tanenthor There are also micro filters that do not require boiling and remove almost all contaminants that are not dissolved.
Answer: I am glad you asked this question. There is an element of truth here. If the water already contains contaminants such as arsenic and nitrates, and/or if the pot that the water is being heated in is contaminated, then boiling (or equally well, reboiling) the water could result in higher levels of these contaminants.
On the other hand, if you are starting with pure (i.e. distilled) water in an inert vessel, no amount of boiling is going to cause these contaminants to magically appear.
Comment: The very same thing could be same about anything you're putting into any container. There's nothing specific to water, boiled water, or reboiled water.
Comment: "Inert vessel" - so no Philosopher's Stoneware?
Comment: To put it another way, in terms of these toxins drinking reboiled water is as dangerous as drinking *more* water. How much more water depends on how long it was boiled for. In practice you aren't going to reduce the volume of water by even 10% just by bringing it to the boil twice under a lid, but you could simmer it. In theory, yeah, you could boil millions of gallons of water down to a nasty dose of arsenic if you could also figure out a way to separate it from the fistfuls of *non-toxic* salts you're precipitating (limescale).
Comment: Does the concentration even matter if I plan to drink the whole amount of water anyway?
Comment: And if the pot is contaminated, it's contaminating each new batch of water, potentially more than any added contamination to first-boiled water.
Comment: I might suggest being careful with the word "amount." Reboiling water doesn't create _more_ contaminant, which is what (on the surface level) the word "amount" implies.
Comment: _"If the water already contains contaminants such as arsenic and nitrates, [...] then boiling (or equally well, reboiling) the water could result in higher levels of these contaminants. "_
How? If the water already contains them, boiling won't magically add more contaminants!
Comment: @Josef your answer is actually in that [...] which you didn't post ;)
Comment: @Josef: Only because some of the water comes off as steam, so if we assume that the steam contains a lower concentration of contaminants than the water, then the water that doesn't boil away will be left with a higher concentration. This is essentially the bit left after distilling water; the process works because the contaminants are generally left in the water. If the original water is comparatively clean compared to safety limits, then the boiled water will be too. It will likely only be a problem if you reboil many times with water that is already contaminated.
Comment: @AndreKR exactly, I hardly doubt it matters. The amount of whatever poisonous stuff in there doesn't change. In fact this whole discussion is entirely moot because there's not enough poisonous stuff in there to begin with (unless you're in some kind of slum with no clean water, but I think *reboiling* water is the least of their concerns).
Comment: @AndreKR: *if* you planned that then it wouldn't matter. But you don't plan that: you don't pour slightly less water into your tea when it's been boiled twice than you do when it's been boiled only once. You aim to fill the cup either way. This is not to say re-boiled water is dangerous (it isn't), but that the reason it isn't dangerous is because the "concentrated form" is still safe (having been only slightly concentrated from a very low starting point), not because concentration doesn't affect your dose at all.
Answer:
There has been some claims that drinking reboiling water is dangerous claiming it produced arsenic, nitrates etc. it this true?

It doesn't produce anything.  Re-boiling water doesn't change the water into anything dangerous.
However, if the water is already contaminated, then lengthy boiling will evaporate some of the water, and the concentration of the chemicals already in the water will increase due to the lower concentration of water.
If you follow the standard recommendation and boil the water for a full minute, then depending on heat input and environmental conditions you could be evaporating as much as a cup of water a minute.  Let's assume the worst case - dry air, very hot stove, lots of surface area on pot, and only two cups of water to start with.  If you boil it for a full minute, you might lose half your volume, increasing the concentration of whatever is in the water twice.
So how can you avoid this without capturing the water from the steam?
Use a lid - a lot of steam collect on there and drip back into the pan.  Boil a lot of water at once, rather than boiling two cups for a minute, boil 4, 8, or sixteen cups.  Boiling a small amount requires little heat, but often people will turn the burner all the way up and leave it there, boiling it off far faster.  By boiling a larger amount, it's matched better to the stove and you'll only be adding the heat needed to get it to a rolling boil, rather than adding more heat than necessary.
Once the pot gets to a boil, turn the heat down - it needs less heat to stay boiling than it does to start boiling.
Lastly, once the minute is up, place the pot on a cool surface to cool the water down more quickly.  It can take 30 minutes to cool to drinking temperature depending on the environment, and during that time it's evaporating faster than normal.  Cooling it quickly will also save water.

Is it safe to drink reboiled water?

It's no safer than drinking boiled water, but each time it's boiled the contaminants become more concentrated.  Limit boiling to only when necessary - if the water has been contaminated since the last boiling.  Generally you won't need to re-boil water, but if you're unsure then you're simply going to have to weigh the risks of biological contamination against the risks of inorganic contamination.
Answer: There is a very unusual case in which reboiling water makes water (marginally) more dangerous to drink.
Suppose that you have a toxin or pathogen in the water that is neither volatilized nor denatured at 100 degrees Celsius. By boiling the fluid, you reduce the amount of $\ce{H2O}$, while the amount of the dangerous substance remains constant. Then, a fixed amount of boiled fluid will have a higher concentration of the dangerous substance than the same amount of unboiled fluid.
This may seem like a bizarre hypothetical, but this exact situation arose during the 2014 Toledo water crisis, which stemmed from a Microcystis bloom in Lake Erie. Microcystis, a variety of cyanobacterium, produces substances called microcystins, which are not destroyed or removed by boiling. The relevant authorities issued instructions not to boil the water during the crisis. (Of course, it is not the case that boiling converts potable water into unpotable water. Rather, it converts unpotable water into very unpotable water.)
That said, the other answers are correct in stating that reboiling water is almost always a safe practice. Even in water that contains a dangerous substance that is not removed or denatured by boiling, boiling the water is unlikely to make it significantly more dangerous to drink, since in practice, one does not typically remove a large fraction of a fluid's $\ce{H2O}$ content when boiling it.
Answer: First need to separate produce from concentrate.
If two or more molecules reacts to form different molecule(s) then you have produced.  Or a single molecule could split.  Or a single could could be changed like trans to a cis double bond.  Cannot produce an element (e.g. O) - it is present or not.  Not a lot of this going on at the boiling temperature of water.  The non bacterial components of water are pretty stable.
Boiling water removes volatile components. Arsenic is a chemical element - it cannot be produced. Arsenic is not volatile alone or as part of another molecule.  What is going to boil off is H20, N2, CO2, CO .....   The non-volatile components will be concentrated.
Nitrate is NO3 so I guess it is possible to produce it as N and O are present in water but that is highly unlikely.  And even if so boiling a second time would not change that.  I don't think a nitrate or anything it is a part of is volatile so it would not boil off.  It would just concentrate.
You cannot produce arsenic as it is chemical element.  It is in the water or not.  It would just be concentrated.
What does happen at the boiling temperature of water is the bacteria is killed.  If you killed the bacteria the first time then it should not grow back.  There is no purpose to boiling a second time if boiling did what it was supposed to do the first time (kill bacteria).
Yes potentially bad stuff could be concentrated but boiling a second time is not a factor.  Boil once for 10 minutes is equivalent to boiling twice for 5 minutes in regards to concentration.
Comment: You can produce arsenic from compounds which contain it. Either way it still isn't dangerous.
Comment: @bon  What?   If it is present then yes it is dangerous.   Arsenic is not just dangerous in element form - in fact that is not a common form.  Did you vote me down?  Regardless you are not going to break down mineral containing arsenic at the boiling temperature of water.
Comment: @bon Either way it still isn't dangerous?  Not according the medical community and  wiki.   https://en.wikipedia.org/wiki/Arsenic_poisoning  They even made up symptoms, diagnosis, and treatment?

Is it safe to drink reboiled water?


What chemicals cause the smell of a septic tank?

Question: I am wondering what chemicals exactly contribute to the smell of a septic tank system. I read about $\ce{H2SO4}$, $\ce{NH3}$, but I am not sure. Is methane also a factor or is that odorless?
Answer: According to the Wikipedia article Septic tanks, as septic tanks are generally anaerobic environments, pungent smells from the formation of hydrogen sulfide $\ce{H2S}$, which is sometimes referred to as 'rotten egg gas'. As you stated, ammonia $\ce{NH3}$ can be produced - also with a distinct smell.
Also, according to the Wikipedia article, fermentation could occur, producing the odourless methane and carbon dioxide as well as phosphates.
Incidentally, $\ce{H2SO4}$is the chemical formula for sulfuric acid.
Comment: While it is true that $\ce{NH3}$ and $\ce{H2S}$ can be produced (larger amounts collect usually only in abnormal conditions), my nose suggests that they are not the main cause of the typical smell (with the caveat that gas mixtures as well as different concentrations can have totally different smell from the compounds). My guess would be leaning towards small amounts of thiols and volatile amines along the lines @KlausWarzecha suggests. Also do not forget butyric acid.
Answer: Some of the "fragrances" are formed in the degradation of different amino acids.
Amaterasu has already described that hydrogen sulfide is an important component in the septic tank perfume. It is formed in the degradation of the sulfur-containing amino acids methionine (1) and cysteine (2).

In the anaerobic degradation of methionine, the initially formed methylmercaptan ($\ce{CH3SH}$, 3) is methylated to dimethylsulfide ($\ce{CH3-S-CH3}$, 4). Further microbial transformations of 3 and 4 eventually yield $\ce{H2S}$ .

The degradation of the amino acid tryptophan (5) furnishes 3-methylindole (skatole, 6), the aroma of feces.
Just for the completion of the sensoric enjoyment: Other amino acids, such as ornithine (7) and lysine (8) form 1,4-diaminobutane (9) and 1,5-diaminobutane (10), respectively upon decarboxylation (= loss of $\ce{CO2}$).

The trivial names of these diamines are putrescine and cadaverine, which suggests another odor than that of roses and lemons ;)
I'm however not sure if the last two compounds are actually formed in septic tanks.
Answer: The smell coming out of a septic tank depends on (1) what goes into the septic tank, (2) how long the material has resided in the tank, (3) where the septic tank is located, (4) the current weather/climactic conditions, and (5) how well the tank is maintained.  The point being, at any given time or location the smell of a septic tank can change due to the emission of a different combination of chemical compounds.
Interestingly, if hydrogen sulfide is overwhelmingly the dominant compound, that likely means the septic tank is being fed sulfur water. This compound is has a very distinct smell of rotten eggs.
Relative to other malodorous compounds, hydrogen sulfide and ammonia have a relatively high concentration.  The high concentration is certainly an issue from the air pollution standpoint,  however, these compounds have a relatively high odor detection threshold compared to some of the other malodorous compounds.
Fresh waste may have odors dominated by indole and skatole which, while not very high in relative concentration, have lower odor detection thresholds.  Because the odor detection threshold is low, a very small quantity of these compounds gives fresh waste its distinctive odor.  Other compounds include the methly sulfides, butyric acid, valeric acid, and phenol.  (It is worth noting indole is a highly unusual compound in that at high concentrations it smells like fecal matter, but at low concentrations it smells like flowers.)
Most people do not notice the odor of a septic system until something goes wrong.  If something is wrong then an unpredictable release of many oddball malodorous organics may be caused by the incomplete digestion of the fresh waste by microorganisms living in the septic system.  If the septic system is operating correctly, then the contents has time to be thoroughly digested by the microorganisms living in the system.  The system should be releasing compounds in the most broken down forms, which would be water, carbon dioxide, methane, hydrogen sulfide, and ammonia.  If the septic system is functioning properly, the odor from the system should be minimal.
-Also, as a side note some septic systems prevent the compounds emanating from fresh waste from coming into a house through the use of traps.  These traps may be in floor drains.  Make sure all traps draining into a septic system are periodically flushed with water.
Methane has no odor.  This may be confusing because malodorous compounds, like dimethylsulfide, are added to natural gas, which is mostly methane, to give its unique smell.  This smell has the purpose of leak detection.
Sulfuric acid and ammonia are used for clog removal and cleaning.  If someone who cannot tell a clog from a backed up septic system tries to throw these chemicals down the drain as opposed to paying someone to pump the system, then all these chemicals may do is kill the micro-organisms.  If the microorganisms die then the system may emit the odor of the chemicals as well as undigested fresh waste.


Why do Jews use lawyers in beis din?

Question: Why do Jews who go to Beis Din to resolve  a financial disagreement, often use "lawyers" (to'ein) to argue their respective sides. If the dayanim are capable shouldn't they be able to just heard the sides and make a decision based on the Torah? Also, doesn't this lead to the richer side being able to hire the better "to'ein" which makes it unfair?
Comment: why do you assume the daynim know all the shittos?
Comment: too broad. jews not judaism. opinion based.
Comment: If this were edited so that it were about the place of lay tribunals in the Jewish legal system, by which each side appoints a person to argue their case, it would be a great question. (And very answerable as well: see Menachem Elon's *Mishpat Ivri*).
Answer: You happen to have a very good point,in fact the Shulchan Aruch CM 13:3 and the Sma 12 write that the dayanim should really only hear from the person himself and not from a toein.
In this article Rav Hershel Schacter explains in detail how corrupt the toein system is and how people are making a fortune off this "profession ".
http://www.vosizneias.com/92931/2011/10/11/new-york-in-exclusive-ami-magzine-intreview-noted-rabbi-schachter-slams-set-up-of-rabbinical-court-system/
Answer: The point is that the individuals are often too nervous to actually show the facts of the case. Also, they are afraid that if the dayanim are not given all the arguments by their side, that they will not get a fair hearing. Part of this is the influence of the American court system. The dayanim are expected to be able to discount the to'ein when necessary.
Answer: BS"D
After much criticism of my first answer (fairly so), there has been much more research and neutralization of the source. To be clear, my first answer was not promoting any program. I was trying to fairly give the source's context, which might be skewed towards the use of To'anim in a Bais Din. (To keep this answer neutral, you can look into the source about to be quoted yourself by searching what Rabbi Meir Simcha Lerner does in Lakewood). Still, Rabbi Lerner provides a rational Halachic source for To'anim as follows:

"The Halacha states in Shulchan Aruch Choshen Mishpat (Siman 17, Seif 9), "If a Dayan sees that a litigant is struggling to explain their arguments in an important matter, then it is permissible to assist him in formulating his argument as the posuk in Mishlei (31:8) 'P'sach picha l'elaim' or 'you should open your mouth on behalf of the mute' as long as you are careful not to be k'orchei hadayanim." This [has been learned to] mean(s) the Dayan cannot become the litigant's advocate. It is clear from this halacha that a Dayan can accommodate litigants stating their case, but the Dayan needs to maintain an open mind for all sides in the case.

The Gemora in Bava Kama 117b tells the story of Rav Abba, who incurred damage and was advised to go to a certain Bais Din that was known to rule in favor of people who incurred such damages. Rav Abba followed the advice and was successful in his Din Torah. [Also,] (a)s mentioned in Tosfos, Shavuos 31A, the Torah considers it a great mitzvah to help a person retrieve money or settle financial matters [and disputes].

Evidence of using the term To'en is found in [Shu"t] responsa from the 15th Century and on. There is also a teshuva in the 1400s from Rabbi Yisroel Bruna, an Ashkenazi Rav who was a primary source for the Rama, discussing the question of whether a To'en can switch sides in the case [proving that To'anim have been used in Bais Din for years]. The S"MA, Rabbi Yehoshua Falk, a talmid of the Rama, at the turn of the 17th Century, wrote in his Sefer on the Shulchan Aruch that it is already an accepted practice to have [one's] (your) case presented by an advocate [to'en] and there can be no objection to this. It is also known that To'anim were frequently present in the Bais Din of the Ha'fla-ah, Rabbi Pinchus Ha[L]evi Horowitz in the 1700s."

It seems that Rabbi Lerner disproves the common notion that the use of To'anim in a Bais Din was influenced by the American court system's use of lawyers. His multiple sources of To'anim being used in Eastern Europe before America was even a country is apparent and follows through in the quoted texts (not found online, you're welcome to search your local Bais Medrash).
Regarding the fairness of the Bais Din system works in our times, there are many issues with both the Dayanim and the To'anim based on Ami Magazine's article interviewing Dayan Schachter from 2011. I am not sure one can confidently say that the system has been improved since 2011.
Some of the noted issues with To'anim, as you ask and mentioned by Dayan Schacter, is that they're known to act very similar to the aggressive manner of lawyers in America's secular courts, where they obstruct litigants from answering questions directly asked by the Dayanim, and ultimately obstruct Yosher (justice).
In Eretz Yisrael, there is a more formal Bais Din system that is part of the justice system. Although it has its wide criticism for fairness and Yosher (justice) similar to the criticisms of the private Baisei Dinim in America, at least the system does have a more formal structure to qualify To'anim, including a required license to be a To'en Rabbani. The licensure is contrary to how anybody can be a To'en in America, although we often find that they're usually lawyers and sometimes also Rabbis.
The biggest issue is the general concept from Avot (1:8) "אל תעש עצמך כעורכי הדיינים" which literally is telling the Dayanim not to act as lawyers for their litigants, as was mentioned by the quote from Rabbi Lerner, above. Although it doesn't mean that it excludes To'anim's ability for representing litigants (as contrarily, one can argue that the Mishna is a source in itself for the To'anim system.) Still, the Mishna's clear instruction to Dayanim is an issue we see with the Borerim system.
In the Borerim system, a Bais Din is formed by each litigant selecting their Dayan and the two Dayanim select a third Dayan. It's often considered straight shochad (bribery) in many talmidei chachamim's opinions because each litigant has to pay their Dayan for one-on-one sessions (where Dayanim often guide the litigants like lawyers/To'anim). Litigants then also pay for the Dayanim's time in Bais Din, where often the litigant who paid their Dayan the most usually wins the Din Torah, according to Dayan Schachter.
Your question is valid where money is often the major factor, and the litigant that pays most often gets his/her way.
Comment: Thanks for the update, this is much better than the previous answer. Rabbi Lerner seems blissfully unaware of the problems with the To'en system, which only worsen every criticism of the Beis Din, without improving anything. Also, His quote from Tosafos Shavuos 31 is rather an argument against toanim, and the gemara from Bava Kama is irrelevant because it does not involve toanim.
Comment: You're welcome. Thank you for your understanding that I was not trying to endorse anything or anyone. I can understand your frustration with the BD system. It's scary how it's so out of whack that a proposed "watchdog Dayanim group," as discussed in the Rav Schacter article, would literally endanger lives. Bez"H Mashiach will come true and return Yosher.
Comment: The source of פתח פיך לאלם only allows toanim in rare cases that litigants have some sort of communication issue. That's not the vast majority of cases, certainly not common enough to make a profession out of
Comment: @DoubleAA, you're right. That's what Rav Schachter argues that the Pasuk is totally taken out of context. Which ironically is a foundational basis of how To'anim win Dinei Torah: taking sources out of context.

Why do Jews use lawyers in beis din?


Earth and moon have different mantle compositions. Is this a fatal flaw in the 'Giant Impact hypothesis'?

Question: Deep impact ejecta on the moon seem to indicate that the moon's mantle is predominantly 'low-calcium pyroxene' (recent letter to Nature), whereas the Earth's mantle (or at least the upper mantle) is dominantly olivine with only ~15% pyroxenes. So how can this discrepancy arise if the Earth and moon have a common origin? The only possibility I can think of is if partial fractionation of magnesium silicates actually took place in space, before falling to either Earth or moon, with the slightly denser olivine falling to the higher gravity of Earth, and less dense pyroxene falling to the lower gravity proto-moon. Is this possible? Is there any isotopic evidence of Earth-moon mantle commonality?
Comment: Please link and/or quote the sources you mention. That way, people can decide whether those assertions are qidely accepted or not.
Comment: Link to the "recent letter to Nature"?
Comment: The closest recent article in Nature of a similar bent I found was a "research highlight", [Moon mantle's make-up revealed](http://www.nature.com/articles/d41586-017-04437-7). Nature's research highlights are not peer reviewed. They are instead summaries of research published elsewhere. In this case, this appears to be the article [South Pole–Aitken basin ejecta reveal the Moon's upper mantle](https://pubs.geoscienceworld.org/gsa/geology/article-abstract/45/12/1063/516687).
Comment: The reason I wrote "appears to be" is because the external link in the Nature research highlight is dead; I instead had to search at geoworld.org for the article. There I found another dead link, this time an internal link in the abstract to the pay-walled article. Even sci-hub can't find the article.
Answer: I highly recommend this blog article from the Planetary Society. It is from 2012 but I believe the science is still sound. The author herself, has received recognition for her contribution to communicating space science to the public (She has an asteroid named after her!!)
It doesn't address your question about if there is a flaw in the giant impact hypothesis through an isotopic analysis, but rather through a gravity anomaly analysis from the GRAIL Mission.

Isostasy, gravity, and the Moon: an explainer of the first results of the GRAIL mission. Written by Emily Lakdawalla, 11 December 2012

The article starts off by giving some information on how gravity anomalies are formed and measured, before delving into the main arguments.
In Summary (all mistakes are mine), using various analysis's of the gravity anomalies, resulting in 3 further scientific papers linked in the article, the GRAIL mission has determined that the Moon has a highly fractured and highly mixed crust. The crust is alot thinner than previously thought and in some places the crust is nearly or even 0 km deep, allowing mantle minerals to be exposed on the surface. The unexpected porous nature of the crust supports the Earth/Moon common origin, whereas before there was a mismatch in the assumed numbers giving some doubt to the giant impact hypothesis.
The article then finishes off by mentioning an existing theory on how the moon could have formed while still creating the observed features we can see today.

About halfway through the article, after discussing Airy and Pratt Isostasy, the article starts to mention the observed results. When looking at the Bouguer gravity of the Moon,

Now, the Moon should have local, small-scale variations in crustal density due to local geology; the fact that the variations are small and smooth means (Zuber argued while presenting these results) that impact cratering has completely battered, bashed, fragmented, mixed, and remixed the upper couple of kilometers of the crust, totally homogenizing it. Previous maps of lunar gravity have not had high enough detail to see this beautiful match between topography and gravity; so this is a new GRAIL result.

a little further on discussing some more results about the density of the moon surface,

There is one big very surprising thing about this map. The average density is 2550 kilograms per cubic meter. This is much, much lower than what has been assumed for lunar crust; in fact, it's lower than the density of granite. We know what the highlands crust is made of, we have samples of it: the density of the minerals that makes up the crust is around 2800-2900 kilograms per cubic meter. For the Moon's density to be so low, Wieczorek says, it must be very porous, fractured and busted up to give it about 12% void space, to a depth of several kilometers below the surface. This is an important GRAIL result. The mission has given us X-ray vision to see that the Moon's crust is absolutely shattered from the surface for thousands of meters down. In places where the crust is very thin, even the uppermost mantle may be fractured and porous.

Here is where the article starts discussing the mantle minerals, especially Olivine which you mentioned. (emphasis is mine)

This map shows crustal thickness is near zero under a few of the impact basins (particularly Crisium and Moscoviense) and some of the deepest craters inside the south pole-Aitken basin (Humboldtianum, Apollo, and Poincaré). And the crust reaches a high of 60 kilometers on the farside. Kaguya compositional data support the GRAIL conclusions. There's evidence for the mantle mineral olivine being exposed in precisely those places where GRAIL sees the thinnest crust: Crisium, Moscoviense, and Humboldtianum.
The average crustal thickness that Wieczorek and coworkers calculated, 34-43 kilometers, is much lower than has previously been assumed. Why is that important? Because when you work out the math to figure out what the bulk composition of the Moon is, given this thinner crust, you wind up with numbers for the abundance of aluminum that are a much better match to Earth's aluminum abundance than they were before. Previously, an apparent compositional mismatch had been a problem dogging the giant impact hypothesis for the Moon's formation. The GRAIL result makes for a compositional match.

Near the end of the article, The article mentions Sean Solomon's idea on how the moon could have formed.

Andrews-Hanna pointed out that some theorists have predicted exactly this situation. The paper he cites was by Sean Solomon, principal investigator on the MESSENGER Mercury mission, who was trying to explain how Mercury could have wrinkle ridges caused by global contraction if the Moon does not.
If you condense the Moon from a ring of debris orbiting Earth following a collision, the first nucleus of the Moon will actually be quite cold. As it grows, the increasing energy of the impacts of stuff onto the proto-Moon would make the Moon's mantle hotter than its deep interior; you could wind up with a cool, solid center surrounded by a hot, liquid mantle. The heat from the mantle would take time to propagate into the interior; as it did, the warming center of the Moon would expand, producing exactly the kind of global extensional stresses that could make this set of dikes. The model has this expansion happening at the correct time, too: before the Moon was 500 million years old, which would be before the end of the basin-forming impacts.

I hope I actually understood the article correctly and that it helped answer your question. Albeit through a different route.
Comment: Thanks for your elegant explanation, which I like - the moon's crust is less dense than we thought, so the moon's mantle must be more dense, bringing it more into line with the composition of Earth's mantle. But there is still a slight problem; we have to argue that the low Ca pyx composition of impact ejecta, mentioned in 'Nature', must perforce be regarded as atypical of the moon's mantle.


How long did it take your baby to like daycare?

Question: My baby started daycare at 9 mos. It's been two weeks and she still cries when we drop off and pick up. How long did it take for your baby / toddler to like day care and at what age did they start?
Answer: Crying at drop-off and pick-up is more of a separation anxiety issue, and it's totally normal.  It has nothing to do with whether she likes daycare.  What you really need to know is whether she cries throughout the day, or if the crying is limited to a brief period at drop off and pick up.
I used to sneak in to daycare at the end of the day and see my son playing happily with the other babies, but as soon as he turned around and saw me, he started to cry.  It's fine.
Comment: thank you! this makes me feel a lot better. I'm going to ask if she's crying all day. super helpful advice.
Comment: I agree.  It is really hard for the parent! Daycare may let you sneak in a bit early at the end of the day to watch your child playing happily.  Seperation anxiety is a sign of a good strong bond with the parent.  Good luck.
Comment: +100. My 2 year old is currently performing Masterpiece Theatre every morning: "We're going to nursery, yaaaay!" and then when we get to the door "No Daddy, NOOOOOO WAAAAH".

One suggestion is to ask the nursery to take some pictures of her throughout a day to see her normal behaviour when you're not there as an audience.
Comment: Yeah, some drop-off crying isn't really something I'd worry about. After over half a year with his current daycare my 1.5y/o son still cries sometimes when being dropped off, but sometimes he cries when I or his mother leave the room for a while. It's just an issue with change, and so long as he settles down & acclimates I wouldn't sweat it.
Answer: In my observation, separation anxiety is age dependent. At six months of age, babies tend to be relatively happy being left with a babysitter. At nine months, they have definitely formed attachments and will protest strongly when dropped off.
Unfortunately, there is not much to be done about crying at drop-off time, other than to say a few reassuring words and letting them cry it out. They will eventually learn that you will return every time, and be OK with it.
Answer: My little one began at 1y1m. The first 2 weeks was a progressive routine, with assistance from one grandmother.
Until today (2 months later) she still cries/ lay-down some tears when she sees me leaving and has to say goodbye or something like it, even when she jumps to her room by herself. But I know that she doesn't cry during the day.
She used to "cry" (some tears) when I was picking her up. Now she just smiles.
To see if she likes daycare, ask her "carers" (don't know how to say "ask the ones that take care of her at the daycare") what she does during the day, what songs they sing, etc., and do the same at home. You'll see if she likes it or have some frightened look.
Answer: Children will go through phases.   I had two children in daycare since they were 6-8 weeks old each; neither cried at first (because that's too young for separation anxiety), but both went through phases in and out where it was easier or harder.  Even after two years old, my oldest would still have weeks or months where he'd cry when we left.  He would be fine within five minutes of us leaving almost every time, but he'd still cry while we were leaving.
More than likely, you won't be able to tell if your child actually likes daycare until they're close to two years old, but you can still look for clues younger than that.  That's when we started being able to tell with our oldest, and we saw a change over the next six months compared to the previous year - he initially liked it, but by the time he was around 30 months, he began to be frustrated more and more (due to a few circumstances changing).  We could tell by how he described his day (within the limits of how one can do that at 2) and by his attitude: he stopped wanting to stay at daycare longer.
For an infant I'd primarily look for him/her to be happy at pickup, but happy to play in the environment.  See if the infant starts to interact with the teachers sometimes even if you are there.  Those sorts of cues show that he/she is doing well, and a good fit at the daycare.


New badge idea: Versatile (related to Stack Flair)

Question: Suggestion to have a Versatile badge for those who have good rep in multiple SE sites.
This is to recognize users active across sites - similar to the combined flair but a badge to go along with it.
This could be 3 tier
Bronze  > 200 in at least 7 sites (or some similar threshold)
Silver > 1000 in 10 sites
Gold > 3000 in 10 sites
The badge would be awarded once per site, so if you qualify for Bronze you would get 7 badges at one shot. That might not be a good idea though, I admit.
Any thoughts?
Update
The community at english.se have suggested the following titles
swiss-army knife, polymath, sage, Da Vinci, homo universalis, protean (Gold), multifaceted, all-rounder.
Though polymath has already been discussed earlier for Generalist
Answer: If the badge is cross site, it should be awarded to the area51 account.
Comment: Even if they've never used Area51?


Temporary website redirect: 3xx or php/meta?

Question: I run a (small) news website which has also a forum in a subfolder of the root. I'm planning to give the site a facelift and a code restructuration, so I wanted to put some redirect on the home page that will point directly to forum's index (www.mysite.com --> www.mysite.com/forum) while I tinker with it.
And that, given the little free time I have, will take no less than a couple of month. Being a news site I'm pretty sure that would affect it's overall ranking, but I need to do it, so:
which is the best way to redirect? I pondered and read here and there about the different means, but I couldn't figure out which is worst for SEO.
Do I use a 302 redirect or use "Location:newurl" in page headers using php? Or I just put a meta tag in the html page (or a javascript, what's better).
Sorry but I'm not really into these things, I may have said something silly, I know...
Thanks
Answer: Do a 307 temporary redirect on the server side. You can do this with PHP or .htaccess, it doesn't matter which. But definitely make sure you send the 307 header as that is what tells the search engines the redirect is temporary and to try again later. Without it they will consider the pages removed which is exactly what you don't want.
PHP:
header('Location: /forum', true, 307);
exit;

Comment: Never heard about 307, so do you think it's the optimal one for a 2-month span of time?
Comment: "Normally, when a Web browser issues a POST request and then receives a 302-Object Moved redirect message from the Web server, the browser issues a GET request for the new location and loses the data in the POST request. With a 307 redirect, the browser reissues the POST request with the original data to the new location." Not necessery in your situation, I think, but can't hurt.
Comment: @Damien, two months is a long time but I don't see why this won't work. I'd Google around just to see if anyone has posted any useful data on temporary redirects for this long just to be sure, tho.
Answer: SEO-wise it's not advised to use a meta-refresh or javascript, because they will not pass pagerank and it'll just evaporate. Instead, use a 302 redirect (htacess or php header()). This will ensure that the original homepage maintains it's pagerank while it's under construction.
But really, can't you tinker with it on a test environment and just upload it to the live website once you're done? That's a lot more SEO-efficient.
Comment: Actually, since 2007 Google has started treating meta-refresh as a 301 redirect if there's no delay, and as a 302 if there is some sort of delay. JavaScript redirects are also treated as 302 if a search engine detects it, but it's not as well supported. Still, it's better to avoid meta or javascript redirects and just use the correct status codes. And Litso's suggestion of developing the new site in a test environment is best.
Comment: Yeah, you have a good point there; but I thought that, given the little time I have to dedicate to the site, leaving it there, rarely updated, without new features and so on would have been "bad". I thought it would have been better to just redirect to the forum (where much of the people converge anyway). But mayb you're right, I should leave it there as is...


Can the 10 commandments be violated to save a life?

Question: According to a book I'm reading (Judaism: Everything You Need to Know About: Jewish Religion) and various other Jews I have talked to say, you can violate the 10 commandments to save a life.
Is this true?
Comment: I would recommend reading the WIKI first : https://en.wikipedia.org/wiki/Pikuach_nefesh
Comment: @AlBerko unfortunately I was not aware of the term but yes the Wikipedia makes it 100% clear.
Comment: It should be noted that the same applies not only to save a life, but also when the danger is to limb, mobility, eyesight...
Answer: A general rule is stated in the Talmud (Ketubot 19a):

דאמר מר אין לך דבר שעומד בפני פיקוח נפש אלא עבודת כוכבים וגלוי עריות ושפיכות דמים בלבד
for a Master said: 'There is nothing that comes before the saving of life except idolatry, incest and bloodshed only. (Soncino translation)

("Incest" is actually an imprecise translation. The term giluy arayot includes a range of forbidden sexual unions.)
As some of the Ten Commandments deal with idolatry, incest (or other sexual unions in the same category, e.g. adultery) and bloodshed, they can not be violated even to save a life. The others can.
There may be certain circumstances in which the others may not be violated as well, but that would be due to external factors (e.g. desecration of God's name), not due to their status as part of the Ten Commandments (and the reason for the exceptions mentioned above is also not due to their status as part of the Ten Commandments).
Answer: I. Among the 10 commandments there are 3 that are not overridden by pikuach nefesh (i.e. יהרג ואל יעבור):

Idolatry
Murder
Forbidden sexual relations

II. Additionally, all other commandments cannot be overridden under specific conditions:

If a gentile forces him to violate any one mitzva, not for his own personal benefit, but solely to have him violate the mitzvot, and it is in the presence of ten Jews (בפרהסיא), he should sacrifice his life and not transgress.
or in a time of persecution against obedience to mitzvot (בשעת גזרת מלכות).

Source: Bavli Sanhedrin 74a and Maimonidies Yesodei haTorah - Chapter Five, Shulchan Aruch Yore Dea 158
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/88713/discussion-on-answer-by-kouty-can-the-10-commandments-be-violated-to-save-a-life).
Answer: (Caveat - I'm not religiously a Jew, I only have a Jewish family background.)
With due respect @Alex and @Kouty - their answers and the sources they quote implicitly regard the saving of the life of a Jew. Non-Jew ("goy") life is held in much lower regard.
As an example, just recently in 2012, the most highly-esteemed religious leader and halachic rule-maker among Sepharadi Jews in Israel, Rabbi Ovadia Yosef, ruled that a doctor should not violate even the commandment of observing the Sabbath to save the life of a Non-Jew. But this is an example of a "in principle X but in practice opposite-of-X": Yosef ruled that because the law requires otherwise (and there are all sorts of reasons to respect non-Jewish state law), it is ok to violate the Shabbat; and that doctors can use a Halachic "trick" to get around the restriction by working in teams of two; etc.
This continues a long line of ambiguous rulings of the same character, which forbid, yet effectively-allow violating the Shabbat to save a Goy (excerpt taken from here):

יסוד ההיתר כדי למנוע סכנה מיהודי מבואר בחת"ס יו"ד קלא, ודברי חיים או"ח ב, כה. וכ"כ אג"מ או"ח ד, עט; רשז"א בשש"כ מ, הערה מז; צי"א ח"ח טו, ו; ח"ט יז, א; יבי"א ח, לח. ויש להוסיף שלרמב"ן (הוספות לעשה טו), מחללים שבת על הצלת גר תושב. וכן דעת רשב"ץ. ויש אומרים שגם בלא קבלת המצוות בפני שלושה מי ששומר בפועל שבע מצוות נחשב כגר תושב (מהרי"ץ חיות, רמ"ד פלאצקי). וכ"כ הרב רבינוביץ' במלומדי מלחמה מג. ולדעת רבים אין מחללים שבת על גר תושב, וגם אין כיום דין גר תושב. אבל לכל הדעות מצילים כמבואר למעלה. ובבית חולים שמתנהל על פי ההלכה, יש להעדיף לקבוע בשבת תורנות לרופאים ואחיות גויים, ואם יגיעו חולים גויים, יטפלו הגויים בגויים. ואם הגיע גוי עם מחלה שהרופא היהודי מומחה יותר ברפואתה, ורגילים בימות החול לפנות אליו במקרים שכאלה, יטפל הרופא היהודי בחולה הגוי, גם במלאכות דאורייתא.

So you have Rabbi Moshe son of Nachman, Rabbi Moshe Sofer (the Hetem Sofer), Rabbi Shimon son of Tzemah Duraan etc. - and these are Halachic heavy-weights going back many many centuries.
Now, the examples I gave so far are just about the Sabbath, which is a relatively "weak" commandment, i.e. there are quite a few excuses for violating it. And on the other end of the spectrum, the super-strong commandments are not violable, as the other answers suggest.
What I really can't tell you is what the deal is with the in-between commandments. For example, is it allowed (in practice) to steal in order to save a Goy's life? I'm sure some Halachic scholars have considered these questions, but better-versed people than me would need to fill you in on that one.
PS - The lives of non-Jews are sometimes forfeit, or you are even commanded to just kill them. For example, non-Jews living in the lands which the Jewish god has promised to Jews/Hebrews - the fundamental principle is that they need to be exterminated, including men women children and livestock see Deuteronomy chapter 20, verses 16-18. But this is not done in practice, and two millennia of post-biblical Halachic scholarship basically say otherwise. I've only provided this quote to emphasize how these things are complex and have contradicting layers of what is required in principle.


Importing data from Word document into a SharePoint List

Question: I understand how to import data from an Excel file into a SharePoint list. We have a problem where we have 200-300 Word docs, each consisting of 3 or 4 tables of information. I want to get this information into a single list in SharePoint without having to convert and clean the data in excel first.
Comment: Steve what sort of schema do these documents conform to? Could we see a sample? Would it be ok if I wrote a PowerShell script for you to do this or maybe a C# executable?
Answer: In order to do this you'll need to have Word installed on the box you'll be running this solution from. If you're wanting to push this directly from Word to SP in one fell swoop, that means installing Office onto one of your servers. From there you're going to need to utilize the Word.Interop API to open and read the Word document, figure out how to read your tables into memory (if they're saved as HTML, it should be a simple matter of doing a string split on the  and  elements; if they're not... I'm afraid I don't know off-hand how to read tables out of Word), and then either import the table data directly into SP lists or use the Excel.Interop API to bring the data into Excel spreadsheets which you can then upload as documents into a library.
With 3-400 documents I could still see where this would be a lot faster than manually copying and pasting each and every table into Excel and then uploading the spreadsheets to SharePoint, but it's still by my estimation going to take you a while...
Answer: You would have to build a script that pulls the tables from your documents and write them back to SharePoint. This could be done with a macro, but to me it seems to be more work than just moving the content from Word to Excel or Access, then pushing it to SharePoint.


Use the same database or replicate it for reports and web

Question: I would like to know if i have a web with a huge Database and  throw expensive (in time)reports , the best way to do this is with one database for the web and a replicated one for reports, or only one for both, i'm worried that users can throw reports for 5 or more years because they need that information and the web crashes because of this.
Answer: Neither nore - time to make a second database that is optimized for reporting. This is standard operation procedure and is called a "Data Warehouse".
This should possibly also work on separate hardware, but this is "arguable" as long as the server is good enough.
Transactional databases (OLTP - highly normalized) and reporting databases (OLAP - star schemata, different design characteristics) do not mix well for larger loads.
Answer: replicate/copy or do something!
Yes! because of the nature of OLTP, locking and resources you do not want to be running report queries against a production live copy of your db.
Setup replication to another server, or something to get copies of your prod data onto another box.  The large scale measured & proper approach is DW's, ETL's star schema ect.
For a small system its baby steps though.


Poor Wifi Signal Strength

Question: I have a Ralink RT 3290 802.11 bgn adapter & a DLink N600 router.  I never get more than 3 bars on my laptop, even when the router is positioned in various places in the house.  But I can see full bars on my neighbour's security protected network, which is farther away and through more walls. Is there any way to get my HP laptop to get better signal, or get my router to transmit better?
Answer: You could try a parabolic reflector. Check out this Parabolic Template;
http://fleamour.wordpress.com/2012/10/21/parabolic-reflector/
Using just printable white card, tin foil, scissors, a craft knife & Pritt Stick, you can improve your wireless reception.  The tin foil only needs gluing to rectangular section alone.  Mounted to your routers aerial (or x2 or even x3 aerials) you should see a measurable increase in reception.  You can use one such utility like Wicd (installable from standard repos) under Ubuntu for measuring link strength.
I found it makes all the difference between a rock solid connection in bedroom with door closed & not even detecting a network at all!  As far as free fixes go it's pretty impressive & I might not actually need that mahusive after market aerial ordered from Hong Kong.
Comment: While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.

Poor Wifi Signal Strength


An online wallet service could "lose" my bitcoins?

Question: At bitcoin.org, there's a prominent notice that an online wallet service could "lose your bitcoins."  As I understand it, all bitcoin transactions, and therefore wallet balances, are stored in the block chain, on the peer-to-peer network, so they would not be lost in the event of a service failure.  I suppose that the notice is meant to warn against loss of bitcoin addresses/keys, right?  As long as I back up my keys locally, I can always recover my bitcoins, right?  (Nevermind the case of an untrustworthy wallet service that doesn't protect my keys, or uses them to rob from me.)
Comment: yes it could, just as a bank could loose your money. The difference is insurance.
Comment: Huh?  A bank could lose my money in the sense that a server of theirs could crash and not recall the amount of money I have saved with them, but I don't understand how that applies to bitcoin, where (I suppose) every client maintains a copy of every balance.  Insurance comes from government, and I understand that there is no such thing for the bitcoin economy.
Comment: A bank gets robbed, you loose your money. and exchange wallet gets hacked you loose your btc. A bank goes under and cant pay your money back, an exchange mismanages funds and cant pay your money back. The risk that your talking about is inherent in any market.
Comment: For the highly technically minded you might want to read [this question (and answer)](http://crypto.stackexchange.com/questions/746/how-should-one-implement-a-delegated-shared-trust-protocol) on Crypto Stack Exchange that covers sharing private keys across trusted third- and fourth-parties.
Answer: The loss refers to a few things, all centered around the simple fact that using an online wallet creates a SPOF (single point of failure).
Consider effects on your balance when:

Online wallet operator incompetence enables

Accidental deletion of private keys for addresses in which your balance is stored.
Security vulnerabilities in proprietary code may let someone else send your balance elsewhere or store your keys for theft if and only if your balance gets large.

Online wallet operator dishonesty enables

Operator or its government(s) to seize your balance.
Vendor lock-in if you cannot derive the private keys yourself (e.g. your password simply decrypts client-side private keys stored on the wallet service).
Theft if the Operator decides to close shop, be it a MAD scenario or theft of balance once private key is exposed.

One should only use an online wallet with these features:

Service cannot derive private keys

Private keys are stored encrypted
Keys are decrypted client-side
User is prompted to accept code updates
User is permitted to review client-side code before accepting updates

Service offers portability

Once decrypted, private keys can be shown to the user
User tests import to another wallet client, be it a service or fat client

Service offers two-factor authentication

Password and security token authentication
Security token is decentralized or wholly random (RSA, Google Authenticator, etc.)
Security token is hardware-based and single purpose (YubiKey)
Comment: Very informative answer.  Just to be sure I understand:  (1a) I protect myself by keeping a backup of all of my bitcoin keys/addresses; (1b) I should use a trustworthy wallet service with a good reputation for security; (2a) if I install my own bitcoin client, am I somehow immune from this kind of prosecution? (2b) if I use a service that allows me to save my keys locally, then I'm safe; (2c) this is under the umbrella of a dishonest bank that robs from me because they have access to my private key.  And by heeding the rest of the advice, I can select an online wallet service with little risk?
Comment: 1a) Yes. 1b) Yes. 2a) Yes, assuming that no one can get physical control of your device, or that you don't download a virus of some kind. 2b) Yes, in which case you're basically using a fat client in the browser and the same precautions apply. 2c) Yes. Rest of advice: *in my opinion*, yes, but I'm just one random guy on the Internet with enough StackExchange points to indicate that I probably know what I'm talking about. You should still do research on your own to choose one that is best for your needs. Personally, the only web wallets I use are exchange wallets and I don't store much there.


Problem: Scenes that are unavoidable, but boring

Question: More specifically: Two of my book series' main characters are (temporarily) diplomats.  It's unavoidable to the progress of the plot.  But diplomacy is inherently slow and boring.  So, the general question is: How does one handle boring but necessary scenes?  Both general and specific answers welcome.  Examples from successful books also welcome.
Comment: Diplomacy is a high stakes game of wits. You can make it extremely interesting! Unless of course your diplomats are negotiating with the EU the appropriate length and curvature of imported bananas, I think your readers will be sufficiently interested. You have the power, as a writer, you can make it interesting. It's only boring if you make it.
Comment: Absolutely - I love writing diplomatic scenes in my stories. It's harder than plain old good action, but more thrilling, more challenging and more enthralling. A battle of wits, where hidden behind gentle smiles and mild frowns lethal blows are exchanged. Mild innuendos carrying lethal threats, entangling the opponent into their own lies, entrapment into a cage built of unfulfillable promises - it makes for some of the best scenes I'd ever written! (my other favorite genre is non-verbal dialogue, where two sides just exchange facial expressions and minor gestures, without ever speaking.)
Comment: @SF. Then you will *love* the Foreigner series.
Comment: Lots of great answers and comments here, with useful suggestions and examples, which I greatly appreciate.  I will probably use bits and pieces of many people's ideas, and may get some of those books to read also.  But, it's time to pick an "accepted" answer, and Dale Emery's answer was most useful for my particular needs, so I picked it.  Please feel free to keep adding info and voting.  Lauren Ipsum might get that badge for submitting a really popular non-accepted answer.  :-)
Comment: @dmm I have one of those for the purple prose question. My favorite gold badge so far. :)
Answer: If you want examples of successful diplomacy, try CJ Cherryh's Foreigner series, which I think is up to 15 books so far. The main character, Bren, is a diplomat between humans and the non-human species who are native to the planet where the humans crash-landed. Positively fascinating. Hard going at times, but I was never bored.
And diplomacy is not inherently boring if the stakes are sufficiently high. If the failure of diplomacy is war, genocide, invasion, name your armageddon, then jeez, the reader is going pay attention.
Also, don't make everyone invested in the outcome.

What if your diplomat is a "cowboy" who's overly impressed with
himself? Or she's a stickler for the rulebook no matter what? (You
can find both of those in Star Trek, I think.)
It's been quipped about a certain political stalemate in our own time
that one party "never missed an opportunity to miss an opportunity."
What if one of your diplomats is an idiot, or an obstructionist, or a religious nutcase? (Martin Sheen's president in the movie of The Dead Zone.)
What if your diplomat is a sentient AI come to test your species
before annihilating it? (Battlestar Galatica, the Ron Moore
version, the miniseries.)
What if your diplomat doesn't speak the language, or the translator
disappears? (Also Trek, "Loud as a Whisper.")
Comment: Star Trek - Captain Kirk (_The Original Series_) is a "cowboy", Captain Picard (_The Next Generation_) and Captain Janeway (_Voyager_) are different types of rule-sticklers.  Picard finds loopholes, Janeway skirts the intent by following them to the letter.
Comment: @Izkata The "stickler" I was thinking of was the guy from "A Taste of Armageddon" (where Scotty says "the best diplomat is a fully-loaded phaser bank"), but you make good points about Picard and Janeway.
Comment: You should also check out non-fiction books on diplomacy; I recommend David Fromkin's _A Peace to End All Peace_ (Britain and France haggling over how to divvy up the Middle East after WW1) or Robert Service's _Spies and Commissars_ (Soviet foreign relations immediately after the Russian Revolution).
Comment: This was exactly my first thought when I read the question :D
Answer: If the scene is boring, it's not necessary.
Think about what you actually need to convey to the reader to move the plot forward, write something interesting that delivers that necessary information, and skip everything else.
This may be a good time to break the "show, don't tell" rule. "Eight hours and two liters of vodka later, Ambassador Königsberg agreed to waive the Union's trade rights on Svalbard VII in exchange for a military base on Copernicus Prime and five tons of unobtainium." Carriage return, hash mark, carriage return, onward.
If the scene is necessary because of some shift in a character (e.g., the Ambassador decides that he wants to betray the Union), then find some interesting event that tips the balance in the character's mind, dramatize that event, and summarize what comes before and after.
Comment: Yes, this.  You can see some good examples of this toward the end of *1634* (one of the books in the "ring of fire" fantasy series), where we get the sense of what the characters are doing but not all the boring details.  We see the prime minister's mind wandering during negotiations, meaning we get snippets of conversation mixed with his thoughts.  His thoughts are more interesting than the negotiations, so the author went with that. :-)
Answer: In addition to the always wise advice to omit the boring parts...

Summarize the boring parts in a short paragraph. Maybe simply refer to them in passing.
Complicate the terms of the negotiation until the negotiation becomes interesting.
Add conflicts or problems until the scene becomes interesting. These conflicts need not be related to the subject of the negotiation.
Add a ticking clock. The ticking clock need not be directly related to the subject of the negotiation.
Disable the viewpoint character in some way, such as by distraction, injury, fatigue, urgent concerns elsewhere, or some other condition that diminishes the character's abilities.
Increase the stakes of the negotiation.
Complicate the relationships among the negotiating parties. Ex spouse. Former boss. Parent or child. The guy who shot the viewpoint character's father and got away with it.
Comment: "These conflicts need not be related to the subject of the negotiation" might be the critical trick. The scene can do double duty: necessary plot progress via the diplomacy, and non-boring character development simultaneously.
Answer: As I understand it, most authors of bestsellers ruthlessly cut out boring scenes.  I've seen comments (from such authors) that if they find a section of their own writing boring, they expect readers to find it still more so.  (This does not keep some bestselling authors from padding their books with boring stuff.)
One way to avoid the problem is to tell what other things the characters are doing during the boring interval in their lives.  Consider a few brief sentences about the diplomat's day of work, followed by a few paragraphs or pages about their dissipated nights or intellectual evenings or telephone calls they make during breaks.  Or consider briefly listing a few extremely boring items, then saying "Such were the highlights of the week".
Answer: The other answers have shown how diplomacy can be interesting.
But lets assume your question means that it is important to your plot that your characters are diplomats, but that their work as diplomats is not important to your plot, for example because their role as diplomats allows them to easily cross a border or gain access to some place or information or simply gives them a cover story.
This is similar to a character sleeping: its what they have to do, but its not usually interesting from the point of the plot and you wouldn't bore the readers with telling how your character lays down, pulls up the blanket, closes his eyes, starts to drift off listening to the wind, what he dreams about, how he moves in REM phases, how the light changes with the clouds moving across the moon etc. You just briefly state that they sleep, no more.
With everything else, like diplomacy, you can do the same:

After he was done, John went to bed. When he got up in the morning ...
Pete and Paul went to meet the ambassador. When they came out of the embassy ...

You might include the topics discussed, the outcome of the conversation and anything else in such a short summary, or simply have the visit to the ambassador happen between scenes and let your characters discuss the meeting:

"Okay, let's go see the ambassador."
*
When they came out, Bob and John looked at each other and shrugged. "Well, that was probably the most boring hour in my life."
Answer: I'm partial to a bored diplomat:
"... would such a ratio be acceptable?" The question hung between the diplomats like a point of contention. As Julie began to form her answer she wondered what ratios had to do with the color of her nail polish and the remembered they were talking about commodities, Peruvian coffee or was it pork bellies? Oh shit!
Comment: haha, see there's another option I hadn't considered!
Answer: Michael A. Stackpoles trilogy "Age of Discovery" has a lot of fighting, but many of the characters engage in diplomacy. Diplomacy is a major part of the plot and actually driving the plot (conflicts between bureaucracy and the government, conflicts between nations, conflicts inside the nation). I thought a lot of this made the world seem more real, and especially gave the characters opportunity to think and develop.
The diplomacy basically happens between enemies. All parties stick to the protocol, but find ways to insult each other. Conspiracy is another type of diplomacy. Everyone has their goals, everything is trickery. Sometimes the cards are laid open, but only when the other has no other choice than accepting an offer. I feel there is nothing more boring than stereotype characters. The "bad guy" is not bound to be evil, the "good guy" is manipulating as well, bureaucracy does their thing and engages in conspiracy in the worst possible way, too. The characters draw conclusions and learn, develop. Growing/developing characters are interesting.
Comment: Could you add something about how he makes this work?  How does he make the boring parts less boring?  Thanks.
Comment: Well the diplomacy basically happens between enemies. All parties stick to the protocol, but find ways to insult each other. Conspiracy is another type of diplomacy. Everyone has their goals, everything is trickery. Sometimes the cards are laid open, but only when the other has no other choice than accepting an offer. I feel there is nothing more boring than stereotype characters. The "bad guy" is not bound to be evil, the "good guy" is manipulating as well, bureaucracy does their thing and engages in conspiracy in the worst possible way, too. The characters draw conclusions and learn, develop
Comment: Cool.  Could you [edit] that into your answer?  (Comments are meant to be temporary, for getting clarification and stuff like that.)


Secret ballot voting

Question: Is it possible to organize a secret ballot voting in a smart contract

One knows the number of votes casted and who have voted
You know the total results of the voting
However, one doesn't know who voted and what
Comment: I've answered this question here
https://ethereum.stackexchange.com/a/76373/4670 Any feedback is welcome.
Answer: You are cornering a central topic on blockchain voting I have recently worked on and there are not many satisfying solutions available.

The best resource on the net for ideas around that issue is Follow My Vote who are working for ages now on a stake-weighted blockchain voting solution utilizing bitshares. Unfortunately, they only have one developer and they will probably never finish with that project.
But to answer your question:

Number of votes can be easily modelled by incoming transactions. You just have to check if signatures are valid against registered voter lists (if any) and if the transaction is a new vote or an updating vote.
Who has voted - why is this important? If you just want to verify that the incoming transaction is a registered voter, you could implement systems like signed tokens (see below).
Counting the results of the voting is simple math within the smart contract.
Not knowing who voted on what is the most challenging task if you still maintain to goal to only allow registered voters to vote. Nathan Hourt explains his approach of Signed Blind Tokens here on youtube. However, this is brilliant at first glance, but introduces a registrar which in most cases is a centralized authority.

I never wrapped my head around that any deeper. If you find a way how the voter registration and identification can be managed in a decentralized and yet trustless, fraud-proof way, let me know :-)
Answer: I don't know if this answer is still relevant, but I thought about the following:
The blinded vote will take place in two stages:
 1) commit to a hash of your vote + a secret
 2) reveal your secret + vote
By following these two steps, you implement a blinded voting structure, since nobody will be able to digest the vote from the hash, without knowing the secret, and after the voting window has closed, participants can reveal their votes by submitting their password.
Participants will have the incentive to reveal their votes because otherwise their vote cannot be counted.
Comment: In secret ballot voting you cannot reveal who voted for what.

Secret ballot voting


Identify a problem where a potentially winning move draws because of the 50 move rule

Question: I'm trying to recall a particular chess problem. It's related to retrograde analysis. All what I can remember is this: it's an endgame where there is only one way to reach the position, and during last 49 moves there were no captures, so a potential winning move draws instead.
Comment: Incidentally, the term among computer chess analysts and tablebase developers for this kind of position, where you would win if not for 50MR, is a "[cursed](https://python-chess.readthedocs.io/en/latest/syzygy.html#chess.syzygy.Tablebase.probe_wdl) [win](https://www.chess.com/blog/the_real_greco/glossary-of-computer-chess)" (or a "blessed loss" from the other player's perspective).
Answer: There are dozens of problems that illustrate a potential winning moves that instead leads to a draw because of the 50 move rule.
One example is the following mate in four published by Léon Loewenton in 1956 :
<code>[fen "5KBN/p2ppp1r/1p4pp/b7/RP6/1PP4P/1RpPPPkP/n1B1Q1N1 w - - 0 1"]

1. Nf3 Rg7! 2. Kxg7! (2. Qg1+?? draws)
</code>
There is an apparent mate in three moves: 1. Nf3 followed by 2. Qg1(+) and 3. Qg3 mate.
However, after 1. Nf3 Rg7! 2. Qg1+ black claims a draw according to the 50 moves rule (the retrograde analysis is left as an exercise to the reader!).
If white plays 2. Kxg7!, the capture breaks the 50 move chain and white can mate with 3. Qg1(+) followed by 4. Qg3 mate.
Answer: Welcome to stackexchange.com, dveim.
There's a great answer already, but I think there's a couple of interesting points that I can add.
First, in the composition world, there's a convention which states whether the 50 move rule applies by default only to retro-problems. See Chess Problem Codex Article 17. So all these very long "cursed wins" found in the tablebases don't get interrupted. However the retro problems mostly rely on the rule. But for some problems the convention would work the wrong way round, and in these cases the convention would be ignored, e.g. Elkies' famous problem.
Now, some problem composers think that castling should reset the move count. I personally think that this is illogical: if this were so then any king or rook move which disrupts castling rights should reset the move count. But there are great enthusiasts for this interpretation.
Another corner-case is what happens when the 50th move delivers checkmate? The FIDE rules for 75-move draw are clear: mate trumps draw. However to conclude the same thing for 50-move rule requires looking at the mechanism for claiming draws. It assumes that no-one delivering checkmate would want to claim a draw instead, and that coupled with the fact that someone would be checkmated before they can claim a draw in their own turn effectively means that "mate trumps draw" for 50-move rule. But, although this is the FIDE intent, it doesn't explicitly say so, and some composers like the idea of creative ambiguity here. I personally think that mate trumps draw for 50-move rule.
Finally, there are currently 160 problems in PDB Chess Problem Database See overview here, of which an amazingly proportion of 94 are by the late great Russian composer, Nikita Plaksin.
EDIT: STOP PRESS: I deliberately skipped over the fact that the Codex of Chess Problem Composition had no formal notion of 50-move rule (or draw by repetition)! The sections of the FIDE Laws which cover these were deemed not relevant by the Codex. In the last few days, in Vilnius, at the annual Congress for Problemists, Footnote 12 of the Codex has been fixed in this regard. There is still the problem of how to translate these rules to the Problem world - the castling and checkmate issues are problems for the 50 move world, and the happy acceptance that composers are "free spirits" means you can end up with vague compromise assertions which are a barrier to retrograde analysis.
Comment: True, FIDE's laws don't explicitly say "mate trumps draw", but this can be deduced from them: Article 9.3: "the game is drawn upon a correct claim by a player having the move...". Article 5.1.1 says that mate "immediately ends the game", so the mated player doesn't get a move in which to claim a draw. Yes, it could happen that the turn player could mate but could claim a 50-move draw instead, but I don't see that that casts doubt on "mate trumps draw". For draw to trump mate, FIDE's laws must imply that such a 50th-move mate isn't mate, and they certainly don't do that.
Comment: I agree with you Rosie. Certainly draw can't trump mate. But there is a school of thought that the situation is indeterminate. I don't think that is fair. The intention of the laws is made quite clear by analogy with 75-move rule. But we are free spirits... sigh


Are driving questions on-topic?

Question: Is this site specifically for maintenance and repair, or are we going to allow questions about driving practices?
Answer: No.
Questions about driving, unless they are specifically related to car maintenance, are likely to contribute to a "car talk" atmosphere. We are trying to attract professional vehicle maintenance experts to a site which, like Stack Overflow, has deep, highly technical conversation.
Answer: I agree that in general many driving questions would be off-topic for a "Maintenance and Repair" site.  However, I think there is a certain subset of these questions which may be more relevant, and perhaps warrant some special attention.
This question is a good example:
https://mechanics.stackexchange.com/questions/21/rear-brake-on-motorcycle-closed
Although it runs afoul of some general StackExchange "good subjective/bad subjective" guidelines, I think it could be a salvageable question.  The reason it is relevant is because it does relate to a mechanical component of the vehicle, and the reason it deserves special attention is because it seeks to address the proper and safe operation of the vehicle.
While this site's primary purpose is to cover "Maintenance and Repair" issues, I would suggest that issues that relate to the safe usage of mechanical components also be on-topic.  I'm sure there's nobody here who will disagree that safety should be a primary concern of any driver on the road.
I think that individuals who are experts in the mechanical functions of a vehicle's safety features would be the ones best qualified to answer questions such as these.  In fact, I would almost go so far as to say it would be irresponsible of this group to ignore such questions when they can be appropriately answered here.
Additionally, consider this question which is not at all about any mechanical part - nor any part of an actual vehicle, for that matter - and yet it has received a few decent answers, no down-votes, and no close-votes:
Preventing visor from fogging
Despite being otherwise irrelevant to the topic of this site, the question seems to have been welcomed as it is relevant to the safe operation of a motor vehicle.

EDIT:  Here's another question that may fit into the category of "driving questions we may want to allow":
https://mechanics.stackexchange.com/q/171/78
This question as it is now may be a little misguided (see my comment on the thread), but it does venture into the realm of what I'd like to call "preventive maintenance through good driving practices".  There are some things that one can be mindful of in their day-to-day driving habits, which will help to keep their car in better shape.  While perhaps not quite as significant as safety issues, I think these still have some relevance here also.
Answer: It depends: did you break something?
The background behind a situation can help in the diagnosis.  The missing piece in forming a useful question is likely "what is the problem that you are trying to solve?"
Concrete driving motivated and non-rhetorical example - I have seen variants of something like this in the past:
At a track day, I experience significant brake fade after a few laps.  Would stainless steel brake lines reduce the fade?  Would I see shorter stopping distances?
That's a driving-motivated question with a mechanical answer.
BTW, the answers to my hypothetical questions are "in general, no and no.  The brake pedal will feel better but your stopping distances will likely not change."
Answer: Some problems don't manifest when a vehicle is idling in a shop.  I think questions about how to drive a vehicle to troubleshoot various systems should be on topic.  Maybe something like "Is driving a figure eight in a parking lot an appropriate way to test a suspect ball joint?"
Answer: Yes.
Since questions about driving practices would be a subset too small for its own site, a site proposal about "Car driving" or similar would soon be voted to be merged with this site.
Comment: *because it doesn't fit elsewhere* is not a good reason for inclusion here.
Comment: Also note that downvotes on meta sites are not a 'bad' thing. They just signal disagreement (so don't feel bad that you got a bunch of downvotes :)
Comment: @Theodor: Sorry, but I disagree. This website is called Motor Vechicle Maintenance and Repair, not Motor Vechicle Driving. We should stick to that.
Comment: If we allowed such questions, the answer would be to change the site to just be about automobiles, repair, maintenance, and driving. But let's see how this site progresses for now, we can always vote to increase the site's scope later.
Comment: @Theodor - While I agree that *some* driving questions are relevant here, and cannot disagree with your prediction, your stated reason is not enough on its own to be a good one for including all driving questions here.
Comment: Ok, while I still think it is a valid enough reason, the "Yes." might trigger alarms to people thinking I'm pro questions like "How do I drift?". I am not. But again I do see your point. @Michael - I'll try to stay strong ;) @Iszy - Yes I agree, the questions should be relavent and answerable in an objective manner first of all.

Are driving questions on-topic?


Finding derivative at a point in a set

Question: If I have a few values for f(x), i.e. {(0,1), (2, 3), (5, 6)}, is there a way to calculate the derivative at, say f(6), without interpolation?
Answer: No. You cannot. Given any finite set of coordinates, there is a continuous, nowhere-differentiable function with those points on its graph. Moreover, we can construct everywhere infinitely-differentiable functions with those points on its graph to give any derivative value we like at a given finite set of values. (Both of these claims are readily shown using bump functions, and the former claim also uses the fact that there exist continuous nowhere-differentiable functions.)
We actually need to know the function, or at least know how it is defined on a set having the point we're interested in as a limit point.
Comment: Right, that was my intuition but I hoped there was something clever out there. Thanks.
Answer: In general, no. Even interpolating the data doesn't give you any guarantees that you're capturing the behavior of the function.
If I gave you four nails, could you identify the house that it builds?
Fundamentally, this is because a derivative is defined as a limit... without something to tell you how the limit behaves, you cannot estimate the derivative.
That said, there are things you can do if you want to approximate a derivative if you know the properties of the data. For example, most GPS systems record your driving speed to within 1/2 of a mile per hour (or kilometer per hour). Obviously, your speed is continuous, so if you have a sufficiently large set of GPS speed data, you could approximate the acceleration your car undertakes at any point by attempting to smooth your quantized data.
Comment: Good answer, thanks.

Finding derivative at a point in a set