How much loan was given to Lord Venkateshwara by Kuber?

Question: In the story of Lord Venkateshwara, He had taken loan from Kuber in order to marry Padmavati. Kubera gave the loan on the condition that Vishnu cannot return to Vaikuntha (heavenly abode) without paying off the debt. Lord Vishnu resides at Tirumala as Tirupati Venkateswara without returning to Vaikuntha until the payment is made. To help him repay his debt, devotees offer him wealth and in return Lord Vishnu fulfills their prayers. Through a facebook post, I came to know that daily contributions in Tirupati Temple is approx INR 8 crore. I want to know how much was the loan given by Kuber to Lord Venkateshwara and looking at the contributions whether the loan is still pending and if yes then how much is still pending?
Comment: The loan was for 1.4 million Ramamudra coins.  My understanding is that donations to the Tirupati Hundi are only applied to the interest on the loan, not the principal, and the principal of the loan is only due at the end of the Kali Yuga.  Perhaps Kubera set a  really high interest rate.
Comment: Also, I don't think Vishnu's decision to stay in Tirupati has anything to do with Kubera's loan.
Comment: @KeshavSrinivasan I read this from wikipedia page on Lord Venkateshwara at url: https://en.wikipedia.org/wiki/Venkateswara. Can you please confirm this story with what you're telling and put that as an answer.
Answer: The loan given to Lord Venkateshwara by Kubera was 1.4 million in Ramamudra Coins.
The loan was given under the condition if the debtor makes an executory note. The promissory note was dictated by Brahma and Lord Venkateshwara himself wrote it.

This, the 7th day of the bright-fortnight of the month of Vysakha in Kaliyuga, The debtor is Srinivasa, 'the creditor is Dhaneswara. Purpose : marriage of the loanee. Amount of Loan fourteen lakhs in Ramamudra coins. The loanee should repay it with interest in one thousand years after the loanee's marriage." Brahma and Siva attested as witnesses. The scribe was the loanee himself. After accepting the promissory note, Kubera paid the amount in cash. Srinivasa requested Kubera to purchase and get all the articles and material required for the marriage Viz., clothes, pulses, rice, wheat the auspicious Mangalya thread etc.,

Above passage is an excerpt from Sri Venkatachala its Glory by Chalapati Rao. This book contains the Sthala Purana (temple legends taken from various Puranas). This book is co published by Tirumala Tirupati Devasthanams (TTD).
The condition for giving the credit is if the debtor makes the executory note by himself. Lord Venkateshwara did that. Lord Brahma and Lord Shiva signed as witnesses. This loan has nothing to do with Lord's stay on Venkatachala hills. This episode of Venkateshwara taking loan for marriage is just his leela.  He was present there even before that. The marriage happened in this Kaliyuga and there are stories in various Puranas which involve different deities (e.g Kumara Swami. This is from Vamana Purana) and sages worshipping him on the Venkatachala .
The duration period is in Deva years because it is signed in the presence of God. That could take the period approximately upto the end of this Kali Yuga. So, it is believed that what ever he is paying back (from Hundi) is counted as interest rather than the principle. So, the pending amount cannot be determined.
Comment: How much is that in today's value?
Comment: @Sarvabhouma Thanks for ur reply and once again I saw I got no notification for the same. Its only when I checked this question I get to know that it's being answered already. Seems some problem with SE.


Why isn't Arthur woken up by the kick?

Question: First the van rolls, then later the van falls off the bridge. Why doesn't this kick wake up Arthur?
Related questions:
Why do the kicks have to occur simultaneously?
Comment: http://movies.stackexchange.com/questions/2938/why-do-the-kicks-have-to-occur-simultaneously/31193#31193, this would help understand why Arthur doesn't wake up, he needs both kicks.
Answer: Generally, a kick in some level wakes you up only if you physically wake up in that level. If you are sleeping in a chair and you were given a kick, your brain wakes you up from the dream because it considers that an emergency situation. The same thing happens when in the beginning Arthur doesn't let Cobb breathe when he's dreaming so that he will wake up. Because if that weren't the case, he would die dreaming - which is why your brain exits you from a dream. One thing to note here is that you can exit a dream when your brain wants to exit the dream.
If physical kick was not given, it seems evident from the movie that you can exit the dream either when you want to exit the dream or when you get killed in the dream.
When the van was falling, simple reason for why physical kick didn't occur is that these people had seat belts. They wanted to be sure that they could only exit the dream after the job has been done. This is why they planned for two kicks, in case one fails (and apparently had seat belts too).
Also, they are heavily sedated - which means they have to accept the kick at the level below to wake up in the higher level because they can't kill themselves in dream (they may enter limbo) nor could they physically wake up in the above level (they had seat belts).
When the music played, Arthur says "it's too soon" and doesn't want to quit the dream so early, which is why he doesn't accept the kick (rather his brain doesn't accept the kick and wants to continue the dream). However, he accepts the second kick, after completing his job by giving every one a kick in his level (after they completed theirs).
Answer: Reff : Inception Kicks Explained
Here's the deal @Casebash.
In complex multi-level dreams, the sedative is really strong.
In this dream state it is not enough that you receive just one kick.
Each sleeping person requires two kicks. One from the current level of the dream and one from the level above. These two kicks need to synchronized. This is done using the music.
The van hitting the edge of the bridge is the a kick. If they had synchronized their fall in the dream levels below, they would have woken up. However they miss this kick.
The next kick is the van hitting the water. They synchronize their inner layers kick with this one and they ride the kicks back up to the level of the van.
The link has a description of the pairs of kicks each one uses to wake up each level.
Answer: See the accepted answer of this question : Why do the kicks have to occur simultaneously?
(Its also the question posted by the community bot as related question as of the time of composing this answer)
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. - [From Review](/review/late-answers/93735)
Comment: I cannot think of any way to one up the answer given in the link (without copying like 90% of the answer). So trying to make an inferior concise answer that doesn't clear up as much as the original will probably lead to users ignoring the link as well. If you feel like you can do a better job then feel free to do it yourself.

Why isn't Arthur woken up by the kick?


At wich layer "routers" work in architecture TCP-IP

Question: Well, i'm studying to a test, based on the following layers: link, internet, transport and application (Architecture TCP-IP) i would like to know which layer or layers "routers" work and why it can't work in another layers.
Comment: Not quite sure what you mean by, "why can't it work" in other layers.
Comment: I would like to know why router can't work in link or application layer.
Answer: Generally speaking, routers utilize the IP protocol (i.e. IP addresses) to make decisions while directing traffic and do not care about the transport protocol.  The IP protocol would map to the internet layer.
The TCP or UDP protocols would operate at the transport layer.  Typically a device that would direct traffic based on transport layer protocols (or application layer) would include proxies, load balancers, or shaping devices depending on its exact function.
Devices that operate at the link layer (most often Ethernet today) would include switches or bridges.
Answer: Routers operate on the Internet layer of the TCP-IP model. The Internet layer is synonymous with the Network layer of the OSI model.
Comment: Routers operate in some process of "Transport" layer ? Or just INTERNET ?
Comment: Routers are layer 3 devices and primarily operate in Network layer of the OSI model.
Comment: Yes, Drek. I already mentioned that.


"Suggestions as to how to" vs "suggestions how to"

Question: Which should I write?

He has made several suggestions as to how to improve the situation.
He has made several suggestions how to improve the situation.
Comment: "several suggestions **for** how to improve the situation."
Answer: I would say several suggestions for improving the situation.
Your form with as to I find grammatical, but a bit stilted; and with just how I find barely grammatical, though I would not be surprised to hear it in informal speech.
Comment: He suggested improvements for the situation
Answer: I think as to is a form of hedge intended to downplay the "scope" of his proposals. In such contexts, as to (and on) are commonly used to mean concerning, relating to, regarding.
Thus the first version could imply his proposals related to the general subject of improvements. Feasibly some of the proposals concerned, for example, dealing with possible side-effects.
The second implies all his proposals were specifically intended to produce improvements.
Answer: I wouldn't go with either. I'd rephrase it, slightly, as one of these, depending upon the verb tense you need:

He suggested several ways to improve the situation.

Or

He has suggested several ways to improve the situation.

I also would substitute something more specific for "the situation" unless the context has already made it clear.


What's the point of the "advice" tag when people always want to close it?

Question: For example, I have posted quite a few questions regarding mathematics in general, because I want to learn more about the field and I just want to make sure I get an answer or an opinion from someone who has good knowledge about my question. I tag it with the advice tag and I have seen, more than once, that people want to close it or it gets downvoted. It's not like it's a bad question but people don't want it on the mathSE website. So if that's the case and that's how people are going to be, what's the point of the advice tag if people just want to close down the question? And I have also noticed that it's not just my questions, but others as well.
Answer: There are currently 106 (not deleted) questions tagged with the «advice» tag, and only a few of them are closed: exactly 12.
There is the possibility that your questions are being closed for reasons other than the tag!
Moreover, as far as I can tell, none of your three advice questions is closed (although you have an extra one which is deleted)
Answer: I think the problem is one of the kind of advice being sought. From the FAQ:
"You should only ask practical, answerable questions based on actual problems that you face."
All questions asked on the main site should be definitively answerable, in the sense that they should not be open to interpretation, where different opinions may be equally valid. I think that most "advice" questions that get closed are closed because they fail to meet this criteria.
An example of an advice question that might be closed is "What is your favourite method of studying linear algebra?" Whereas the similar question "What are some good books to learn linear algebra from?" would probably not be closed.
Comment: I currently understand "Soft Question" to be a tag for questions that admittedly don't have a definitive answer. If a more open-ended advice question were tagged with both "Advice" and "Soft Question", would that make more sense?
Comment: @Todd Wilcox: the tag would not affect my own choice of whether to vote to close. But soft questions are a difficult thing for the community, and I doubt we are very consistent. It only takes a few people who think a question is "too soft" to vote to close, but different questions may be closed by different groups of voters. So some questions stay open, while others are closed very quickly, without any discernible justification. I do not have a solution to that issue.
Comment: @Todd, Carl, I think you both make good points. I think soft questions are usually (when left unclosed) used for things which may not have a definite answer, but where there is a metric by which to judge "better" and "worse" answers. e.g. any question starting "How can I intuitively understand..." often has the soft question tag. Adding the soft question tag may often make more sense in cases like these. On the other hand, as Carl says, it doesn't take many people to close a question, and since moderation on this issue is a communal thing, there is likely to be a lot of ambiguity in it.


Tips playing F barre chord

Question: Any tips for a newbie in playing the F barre chord.
I find it very hard to put my fingers in place.  I've got a strat.
I hear you can move it up and down the neck for other barre chords.
Comment: I don't know if it's just my guitar, but I find playing the first fret barre chords more tiring than say the 5th fret.  So you may want to practice your barre chords higher up on the neck at first.
Answer: The barre chords are a hurdle for the beginner, and only become easier with practice.  The strat should not be an issue; I play barre chords on an acoustic strung with .013 - .056 and fairly high action - much more resistance than you're likely to have. (I've also been doing it for 40 years...as I say, practice).
Some people wrap their thumb around the neck to fret the low F; this may help, but I personally think it can be a bad habit.
Yes, the barre chords are movable.  In the case of the F form (I think of this as an E barred at the first fret), it'll go up the neck as F, F# (Gb), G, G# (Ab)....
Answer: This question on playing barre chords, or this one may help.
It is all down to practice - as PSU says, you just need to develop the finger and wrist strength through practice.
Answer: I have found that it is not so much the forming of the barre chord, but the movement from the previous open chord. The way I learnt was to try to form open chords where I could without using my index finger, I could then barre quicker.
Answer: Here's something else... As noted, a lot of beginners have problems with barre chords generally. Aside from finger placement, something else to consider is the setup of the instrument. This shouldn't be a big problem with an electric, but many guitars are shipped with an unnecessarily-high action. If the action at the nut is too high, playing any first-position barre chord will be harder than it needs to be.
Answer: Some people tend to like the four-string version of the F over the six-string version, or vice versa. If you are looking at your books and see the 6-string version, or your teacher has taught you using that one, try the four-string version by basically doing the same thing you would do in the 6-string version, leaving off the two lowest-pitch strings, with only the four thinnest strings being used. Obviously you'll finger it differently, but that's a start, and for most guitarists, it's actually a bit easier to use that version. I'm not one of those guitarists, but again, every guitarist is different. In the long run, you should eventually learn to easily do both, but in the short run, you can pick and choose to give your hands time to build.
Luckily, you have a stratocastor, which is a fairly low-action guitar (meaning the strings are close to the fretboard). I have one too, and learned barre chords on it. It took me a couple months to get the hang of them (although I had already been practicing the guitar for quite some time by then), and I literally had to just practice them for a few hours a day, over and over and over again. That's what I recommend doing. Start with the F chord, either the four-string or the six-string version, and just hold it in place and strum for as long as your fingers can handle. Then take a break. Come back, and do this exercise again, and try to break your "record". Keep doing this until you are able to hold it in place for several minutes at a time without your hand hurting too much. They'll probably hurt a little, but you should be able to hold it in place for at least 4 minutes at a time, preferably 5 or 6.
A good place to go from there is to switch between the C chord and the F chord. Actually, it might not be a bad idea to switch between the G, C, and F chords. That's what I did and it improved my hand strength, finger memory, and "chord memory" so to speak. It's not hard to compose your own little instrumental song off of those chords either, and it might be a good idea to try and come up with your own ways of switching between them for several minutes at a time. Keep doing this until your fingers are stinging so badly that you feel like you have to stop. Take a break, then go back. If you do this for a few hours a day, and bring new chords into the mix (such as the A minor, for instance), you'll be very surprised at how quickly you make progress.
The next step from there is to bring in the A shaped barre chords into the mix. Most guitarists find them even harder than the F, and so that's a good place to go after you've gotten good at the last exercise. Do this exercise the same way you did the others, and once you master those, the F will probably be very easy for you to finger.
Doing these exercises, like I just said, will show surprising results if you commit to it. If you practice diligently for a couple hours a day, you'll probably be much better in as little as a month or less.
I hope this helps!

Tips playing F barre chord


Is there racism in Estonia?

Question: I am an Indian man planning to travel around Estonia for a couple of weeks as a tourist. I would be covering Tallinn, Narva, Tartu, Parnu and perhaps one of the islands. I will be travelling alone, backpacking and staying in hostels. Is there danger of racist violence or any form of passive racism (i.e. preferential treatment of white people over black) that I am likely to experience? Are there areas I should be avoiding? I speak English very well, but no Estonian, although I am planning to learn basic words for daily use. Although I am Indian, I am from the south of India and have often been mistaken for being black or of African/American origin whenever travelling abroad. (And not in a bad way, if you know what I mean :-)) I also have prominently visible tattoos over my arm, non-religious and I don't know if they associate this with something specific there?
Any inputs or advice?
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/79272/discussion-on-question-by-alex-is-there-racism-in-estonia).
Answer: I'm Indian, have lived in Russia and travelled to Estonia (and a lot of towns in the interior of in the former USSR where few foreigners visit). I have not experienced racism of any kind. In my years of travel in the region, if there were a few instances of unfriendly behavior, it invariably involved young men who had a lot to drink. You should be able to manage with English.
Answer: There exists racism everywhere on the planet, including in Estonia.
Hans Glaubitz was ambassador from The Netherlands to Estonia between 2005 and 2006.  He is married (or at least was at the time) to a male black Cuban artist (at the time, there were only four countries and one US state where same-sex marriage was legal).  Within a year, he left due to, what he said, homophobic and racist bullying against him and his husband.  However, gossip claims that he was himself behaving snobbishly and that the hostility was rather a consequence of snobbish behaviour than of him being black or gay, or that his husband was simply bored with living in Tallinn and more than happy for Mr. Glaubitz to be placed in Canada instead.
This was in 2006 (12 years ago when I first wrote this answer), and it's quite possible that the incidents were exaggerated at the time and/or that racism (and homophobia) have reduced since then.
An article in De Volkskrant (in Dutch) and in World Press (in English) has more details.
Comment: So much has changed in the past 12 years when it comes to homophobia, racism etc. As far as I understand, the 'issue' stated in the articles was mostly homophobic. If this was an article from 5 years ago I would have upvoted, but I don't think this could still be relevant 12 years later. On top of that, OP is not a public figure.
Comment: @JaneDoe1337 All true, with the footnote that your final remark is probably true but we don't actually know that, although probably most people recognised as public figures in India won't be in Estonia, so maybe OP is a cricket or Bollywood star wanting to go undercover and escape fame for a couple of weeks ;-)
Comment: Wait, I just saw this comment. Hahaha! I wish I were a Bollywood or cricket star, but sadly no! Maybe one day...
Comment: @Alex I've actually read about Bollywood stars going on vacation to the Baltic states as a refuge where they could walk on the street without being approached all the time (or, indeed, at all).
Answer: Disclaimer: I'm estonian and live in Estonia, thereby my view may be quite subjective.
In general, you should be safe. Most people here do not share racist views, although in light of recent years migration crisis in Europe some people have started hate every other human being, having different color of skin or different (esp muslim) religious views - likely same in other European countries.
Probably you should avoid night streets of bigger cities, where drunken young men just look for opportunities to harass someone. Well, I would not walk there myself either.
Otherwise learn few words of estonian (like Hello! - Tere!, Thanks! - Aitäh!), be positive, helpful and likely you win hearts of most local people. Due to the our history (forcefully migrated eastern workers didn't learn single word of estonian for 20 years) few estonian phrases should make wonders :)
Comment: "Well, I would not walk there myself either." It's a very good point that a drunken gang of youths will be abusive to anyone who isn't part of their "crowd", and someone who is black will perceive this as racist whereas it could equally happen to you because you are wearing the wrong clothes. Not that this is any consolation if you're the victim.
Answer: Having recently returned from Estonia and having traveled around the country solo, without knowing the language, I am happy to report that with the exception of the immigration officers, my experience has been completely positive. It is true that people in this part of the world just do not smile and are not gregarious and outspoken, like you might expect in India or the Americas, but they were all very polite, well behaved and helpful whenever needed. No trouble or racism at all.
Comment: Thanks for coming back to confirm!  Please do accept the answer you found the most useful by clicking on the check mark.
Answer: ,,,,Racial disrimination here everywhere; in communication and in relationships and even  in clubs. They give you small glass than local and citizens. I have lived in Tallinn for five years; people have attacked me every where and even in hospitals and everyone is going to insult you if you do not understand russian and estonian language. Someday I asked one women her number what do you imagine?, she gave me man phone and asked her friends to follow me then attacked me physically and when I asked police they even did not follow them almost they did nothing and moreover; their body gestures said they were very happy that some locals attacked foreigner and make him many bruises. I have much to say about my adventure among these racist citizens and locals. You free to try but be quite sure that police here only appearance no one will protect you or any properties belong to you
Good Luck)

Is there racism in Estonia?


"PANIC: early exception 08 rip 246:10" error  with an Nvidia 210G

Question: I have a Nvidia 210 graphics card and have gone in to text mode in Ubuntu and disabled the standard driver and replaced it with the new driver I got from Nvidia's website. Everything works fine but when the computer is off for more then a few hours, the next time I boot I get a weird error message:
<code>PANIC: early exception 08 rip 246:10 error
</code>
At this point I have to take out my new card and drop in a 8500GT card, go back into text mode and re-install the drivers to get my new card to work again. This message even comes up if I try to go into recovery mode before re-installing the drivers. The 8500GT card I can pop-in at anytime and it works no problem with any Nvidia driver installed. Anyone have any clue why this is happening and what to do to fix it???

Dell Inspiron 530
Intel Core 2 Quad 2.33Ghz
3 GB Mem  1TB HDD
Nvidia 210G or Nvidia 8500GT PCIe1
Comment: Have you done a memory test?
Answer: This seems like a hardware problem. Someone else fixed it here with a hardware-related thing.


According to Ramakrishna Paramahamsa and Swami Vivekananda, which is more important in attaining moksha- Bhakti or Jnana?

Question: According to Ramakrishna Paramahamsa and Swami Vivekananda, which is more important in attaining moksha- Bhakti or Jnana? As far as I know Jnana is more important in Advaita and both were Advaitins. On the other hand, most of the teachings of Ramakrishna seem to stress on Bhakti yoga and most teachings of Swami Vivekananda seems to stress on Jnana. Are their teachings contradicting each other?
Comment: Everyone says that Sri Ramakrishna belongs to their school of thought as he followed every possible way and hence concluded that Every path leads to same destination. But surely he emphasized on bhakti yoga. He used to say that কলিযুগে দরকার নারদীয় ভক্তি( one requires devotion like Narada in Kali yuga). I am quoting from Ramakrishna Kathamrita.
Comment: Actually, Jnana and Bhakti are not contradicting.  See [this explanation](http://www.dlshq.org/download/may_ianswer.htm#14) by Swami Sivananda.
Comment: At the beginning of his book, Bhakti yoga, Swami Vivekananda says that Bhakti yoga is the most easy path to moksha.
Answer: They're equally important.
I'm here quoting some relevant quotes of Swami Vivekananda from The Complete Works of Swami Vivekananda/Volume 3/Bhakti-Yoga/Definition of Bhakti:

There is not really so much difference between knowledge (Jnana) and love (Bhakti) as people sometimes imagine. We shall see, as we go on, that in the end they converge and meet at the same point. So also is it with Râja-Yoga, which when pursued as a means to attain liberation, and not (as unfortunately it frequently becomes in the hands of charlatans and mystery-mongers) as an instrument to hoodwink the unwary, leads us also to the same goal.

It is not given to all of us to be harmonious in the building up of our characters in this life: yet we know that that character is of the noblest type in which all these three — knowledge and love and Yoga — are harmoniously fused. Three things are necessary for a bird to fly — the two wings and the tail as a rudder for steering. Jnana (Knowledge) is the one wing, Bhakti (Love) is the other, and Yoga is the tail that keeps up the balance.

There is a little difference in opinion between the teachers of knowledge and those of love, though both admit the power of Bhakti. The Jnanis hold Bhakti to be an instrument of liberation, the Bhaktas look upon it both as the instrument and the thing to be attained. To my mind this is a distinction without much difference. In fact, Bhakti, when used as an instrument, really means a lower form of worship, and the higher form becomes inseparable from the lower form of realisation at a later stage. Each seems to lay a great stress upon his own peculiar method of worship, forgetting that with perfect love true knowledge is bound to come even unsought, and that from perfect knowledge true love is inseparable.

Btw, it is often interpreted that "Bhakti is an extreme love towards Brahman" & "Jnana is the Brahman itself"
Answer: Both paths will lead to God.

Bhaktiyoga is the religion for this age. But that does not mean that
  the lover of God will reach one goal and the philosopher (Jnani) and
  worker (Karmayogi) another. It means that if a person seeks the
  knowledge of Brahman he can attain It by following the path of Bhakti
  too. God, who loves His devotee, can give him the knowledge of Brahman
  if He so desires.
But the Bhakta wants to realize the Personal God endowed with form and
  talk to Him. He seldom seeks the knowledge of Brahman. But God, who
  does everything at His pleasure, can make His devotee the heir to His
  infinite glories if it pleases Him. He gives His devotee both the love
  of God and knowledge of Brahman. If one is able to reach Calcutta, one
  can see the Maidan and the museum and other places too. The thing is
  how to reach Calcutta.

The Gospel of Sri Ramakrishna, Wednesday, June 25, 1884
Answer: nothing complex in it. before going to answer, i just want to say gyan is not knowledge or intellectual. This is something different. when you are learning from outside word, that is knowledge. gyan is about inner world.
one question, any one can gyan easily? probably no. each everyone dont have capacity to attain gyan. very few only the capacity.
Now i tell the answer. gyan is not needed for moksha. but when a person is preparing for moksha, he will attain gyan. like when i m travelling from one village to another village. i definitely cross over many villages. but those villages are my root , not my destination.
Ramakrishna start from village1. Bhakti. When a person is pure bhakti, it lead to get gyan. He reached village 2. Vivekanda attained gyan from his guru. But both concern was moksha. village 3.
Vivekanda knows gyan is a key to moksha. but ramakrishn knew the root of gyan. that's why advised to be in bhakiti.


Low light pixel aggregation

Question: If a lower resolution end image was acceptable, wouldn't it be possible to halve the width and halve the height of a low-light image and take the sum of the light in each block of 2x2 pixels when creating the new (4x brighter) image? After all, if the CCD sensors were 4x as big, they'd surely capture 4x as many photons? I'd expect that if this was done with raw RGB channels it might be as simple as addition, but with a common compressed image format like JPEG the aggregation expression might be different (to accommodate color spaces, etc.) Has this been tried or seen before?
Answer: Yes there have been plenty of cameras that have aggregated pixels in order to reduce noise, from my ancient Fuji Finepix s602z, which would output one megapixel images above ISO400 to the very latest PhaseOne medium format backs which offer higher ISO settings in "sensor+" mode but at one-quarter of the number of pixels (half the width and height).
It's important to note that whilst theoretically you get as much light by summing the values of four small pixels, compared to one big pixel, in reality there is usually a small amount of read noise when getting the value so you get 4 times the read noise with smaller pixels. Some sensors perform the addition (known as binning) right on chip prior to readout and digitization in order to combat this.
Comment: The keyword, as Matt pointed out, is binning.  "Pixel binning" and "signal to noise" are good phrases to use for searching.  :)
Comment: Thanks, Matt (and Eric) for the great answer and pixel binning search suggestion.
Answer: Fuji has been doing this for years. Matt mentioned the older S602Z but they have actually been working and perfecting this.
Since Fuji introduced their first SuperCCD EXR, they have being doing this with additional circuitry to do this earlier in the pipeline. Fuji uses a special color-filter array which is rotated 45° so that there are always two adjacent sub-pixels of the same color. The latest Fuji cameras use EXR on CMOS.
The design lets them solve two problems, one is low-light performance as you suggest. The other is extra dynamic range because they can read half of each pair of adjacent photosite partway through the exposure, before the entire pixel saturates. That way they get two half-resolution representation of the scene which get blended together to preserve highlight details, up to 4 stops (1600% as Fuji calls it).
If you resize an image (JPEG or other) to a quarter of its size, you are doing a similar thing but when the camera does it, it gets better results from what I've seen. However, the difference is minimal from what I've seen.
Comment: Thanks for the insight, Itai. You also answered another question that's been buzzing around my head for a while: can't photosites be sampled midway through the exposure to increase dynamic range? It looks like I might need to borrow a Fuji camera to play with. :)
Comment: Yes, there are different approaches to achieving HDR cmos pixel sites. One of these approaches samples intermediate results before saturation and integrate afterwards. this increases the number of transistors per  pixel, which causes noise and the gaps between pixels increase, which is counterproductive. So it is a trade-off.
Answer: In theory the Foveon based cameras (currently only sold by Sigma) do this.  The most recent cameras (with the Merrill sensor) have enough resolution to make it practical to half and quarter the resolution while still producing a image with a reasonable number of pixels.
Comment: Well, I never knew Sigma made bodies as well as lenses. Thanks for the answer.
Comment: @Jono - Sigma bought forevon, so now they do produce bodies and cameras.
Answer: It is a typical approach to reducing noise and it is called binning. In machine vision cameras it is a built in setting and it is done before the ADC, as to improve dynamic range. This way it simulates a larger pixel size. In post it is more normal to reduce noise by having multiple snapshots of the same static scene and averaging them. But it must be a static scene. Binning in post might have its merits and it cannot be achieved through resizing to 50% so it needs its own function.
Here is before and after post-binning in a dark image viewed at the same size and brightness, then everyone can make their own conclusions whether it is useful enough:
Large for pixel peeping

Low light pixel aggregation


The extension of smooth function

Question: If $U$ is a bounded domain in $\mathbb R^n$ whose boundary is smooth, and $f$ is a smooth function on $U$ whose partial derivatives of all orders have a continuous extensions to $\bar U$. For an arbitrary domain $V \supseteq \bar U$, is there a smooth function $\tilde f$ on $V$ extending $f$?
Answer: The case of a half space is a classical result of Seeley (Proc. AMS 15 (1964) 625-626), and your case should be just a corollary, using a suitable partition of unity and local change of variables near the boundary.
Answer: You can see the Whitney's Expansion Theorem, whose condition is even weaker, that the domain $A$ of $f$ is merely required as a closed set of $\mathbb{R}^n$, and the extended function is analytic.
See Analytic Extensions of Differentiable Functions Defined in Closed Sets.

The extension of smooth function


Which software packages can solve linear systems that are not stored

Question: I have matrices that are extremely easy to compute pointwise, but are too large to store. (they are not sparse)
On the MATLAB site I was told MATLAB doesnt support computations with non-stored matrices.
Is their any other software package out there that does?
Comment: How big are the matrices? If the matrices are so big that they can't be stored explicitly, yet are dense, wouldn't even forming matrix-vector products be overly expensive? PETSc can work with non-stored matrices.
Comment: I assume that with storing you are referring to RAM, but the matrix would stored on a HHD? Or do you have a function which can calculate the value of a given index of the matrix?
Comment: the matrix can be calculated by indices
Comment: Where does the linear system of equations come from?  In many cases large dense systems of equations have structure that can be exploited by specialized methods, but these methods depend on the particular structure of the system of equations, so you'd need to start by telling us where the equations came from.
Answer: If the individual entries of the matrices involved can be calculated on the fly relatively cheaply, as you say, then you could turn to matrix-free methods (also known as black box solvers).  Krylov-subspace methods such as GMRES belong to that class of solvers and would be useful for you because they only require that the user calculates matrix-vector products.  You can do these matrix-vector products by computing the relevant entries of your matrix on the fly, without storing the whole matrix in memory.
The reverse communication routines in the Fortran version of the code available in Templates for the Solution of Linear Systems would match your requirements.
Comment: [MATLAB can do matrix-free GMRES if you give it a function handle that computes the action of the matrix on a vector.](http://www.mathworks.com/help/matlab/ref/gmres.html)
Answer: If the matrices are too large to fit into RAM but reasonably could fit on your hard disk, then you should look at what are called "Out of Core" solvers.  These solvers partition the large matrix into blocks that are small enough to be handled one at a time in memory.  There are many available codes for both dense and sparse problems, but getting good performance out of an out of core solver often requires tuning the code to the particular I/O performance of the computer that you're using.
Comment: I should have clarified that OOC solvers use direct factorization techniques rather than iterative methods.  In the factorization of the matrix you will typically produce intermediate results that are of the same size as the original matrix and these will have to be stored on disk- recreating the elements of the array as needed isn't really an option.  If you're using an iterative scheme, then you can probably compute matrix-vector multiplications without ever explicitly computing elements of the matrix.
Comment: thanks, I'll have a look at it. however, as specified in the comments above, the entries of the matrix can be calculated by entries. therefore, i assume storage on HDD will be a huge and unnecessary waste of time


How can I calculate the proportion of students at an institution who are low-income or first-generation?

Question: I would like to use data from the College Scorecard to calculate the proportion of students who are low-income or first-generation at each institution. In the dataset, I only see "number of" low-income and first-generation student variables. How do you recommend I calculate the proportion, if possible? Divide by the number completed in fill-in-the-blank cohort? Thanks in advance!
Comment: @jknappen - https://collegescorecard.ed.gov/data/ points people to post here for all things `collegescorecard` ... I have mixed feelings but that's the current situation
Comment: What is the connection of your question to "Open Data"?
Answer: These may be the variables are looking for:

Percentage of aided students whose family income is between $0-$30,000   student share_lowincome.0_30000 float   INC_PCT_LO          NSLDS
Percentage first-generation students student share_firstgeneration   float   PAR_ED_PCT_1STGEN           NSLDS

Keep in mind these are percentages of title IV aided student cohorts


Gamma portfolio trading

Question: It is being said that in a long-gamma portfolio, you follow a buy-low sell-high strategy for the underlying stock, which causes you to make profit. The Theta for this portfolio is negative. But it is also said that you can lose money, why though?
Answer: If you are long gamma, your delta is increasing at an increasing rate.  In order to delta hedge this position, you will be selling stock as the stock price goes up and buying stock as the stock price falls.
An explanation of gamma trading can be found in my response to this question:
What really is Gamma scalping?
If you are long gamma, you are long realized volatility.  In other words, you need the underlying stock to move to make money from the gamma (although you may also be long vega, in which case you will make money if the implied volatility goes up and the stock does not).  If the stock does not move, the option position will lose money every day by the theta.  The theta is the premium decaying over the life of the option.
Answer: There are two ways you can lose money:
The actual volatility of the stock is less than the IV you assumed. For example (extreme case) let's say that the stock price does not move at all: you make no money at all on the gamma scalping and you lose on your theta. The gamma scalping counterbalances the theta only if the stock moves "enough".
The stock price moves suddenly (a jump, which violates the BSM continuous hedging condition). You are unable to adjust your hedge and thus you lose money to "hedging error" .(It is not easy to buy when prices are rocketing up and hard to sell when they are plunging).

Gamma portfolio trading


How to create custom Mountain Lion Installer

Question: Is it possible to create custom image of the Mountain Lion with the certain third party applications (Chrome , Adium , Firefox) pre-installed with the operating system. This will not require me to separately download and install these software. This should be similar to installation of the iLife along with the OS installation from the DVDs which came with Macbooks.
Answer: You could do a clean install of OSX on a drive, install your base software, and set up any user accounts you use by standard (or just one "admin" account). Then use a tool like Disk Utility to copy that install over to a USB drive as a DMG file (in disk utility you use the backup/restore tool).
Or you can just install the OS on that thumb drive and use Carbon Copy Cloner to clone it to any systems you need it on.
Naturally you would need to follow all the terms of the EULA and not install this on anyone's machine who asks.
Answer: Since hacking the actual install process is quite painful in terms of time and knowledge required, most people image rather than do the work to change the actual OS installer.
For this, you will want to use a packaging / deployment tool if you do this professionally. Here are three in terms of decreasing cost (and total functionality):

JAMF's Casper Suite
OS X Server's NetInstall
DeployStudio

You can also, just use Disk Utility or another tool to clone a drive and remove the parts you don't want on the standard image. There are lots of tools and ways to accomplish your basic task, so choosing a workflow often depends on what else you need and how often you will be imaging. If you want a linux based NetBoot appliance, this appliance might be a good place to start.


How to start working with Raspberry Pi?

Question: How do I start learning Raspberry Pi?
I know I need to learn:

C/C++ programming
Linux (Debian)
Electronics

What else is there? Also what books would you recommend?
Comment: Although this question is kind of the definition of "too broad" and involves a request for opinion based material, it's also concise and on topic: most of our other questions revolve exactly around the pi, programming, linux, and electronics.  So I encourage people to add answers involving their particular knowledge of how to approach learning whatever subset of these things in relation to the pi. +1
Comment: ergh.. to learn using debian is a good option if you think about installing a debian based distro. but why c++? take a look at perl,pyhton,java or even c++. but IMHO as a beginner you should start with java or python if your scope of application/pi imply that..
Comment: It really depends on what you want to do with it actually. Doing "quite" easy things like a fileserver, mediacenter or webserver etc. You would just need to know something about the kernel. Big projects like home automation needs python knowledge etc.
Comment: @Loko : Nothing could possibly *need* python knowledge because you don't *need* python to do anything.  You *can* use python to do practically anything, but this is true of most higher level languages.
Answer: Do you need to learn C/C++? No, there are countless things you can do with the Pi without ever touching any C or C++ code or using a compiler.  Even lots of programming in other languages which are just as valid.  For example, Scratch, python, perl, java, and so on.
Do you need to learn linux/debian? No, you can run Risc or just use XBMC or other non-linux systems.  Or non-Debian linux distros.  Or you can use debian linux (like Raspbian) without learning the theory of how to compile your own kernel.
Do you need to learn electronics? No, you can make lots of fun projects with the Pi without electronics.  Use it as a mini file server, use it as a tv-top entertainment box, use it to learn about programming, and so on.
You don't need to learn any specific topics.  If you want to play with the GPIO pins and light up some leds, do that, and read up about transistors and stuff as you go.  If you want to learn C++, do that, and read up what you need.  If you want to know more about debian, do that, and read up when you get stuck.
This question is just like all the "what is the best programming language" questions - start instead with what you want to do.  What on earth is "learning raspberry pi" or "working with raspberry pi"?  Then it should be easy to figure out what you need to know to do what you want.
Answer: Linux
Here are three important things for linux newcomers to understand before they go anywhere:

Linux, proper, is technically just an operating system kernel.  If you have an interest in computers and programming, you need to be aware of the difference between the kernel/kernel space and userland/user space. This distinction is applicable to all common operating systems.

The OS colloquially referred to as linux1 (or GNU/linux), includes a userland which completes the system as a very unix-like, mostly POSIX compliant operating system.  Linux is probably the most widely used OS in this category today excluding Mac OSX (which is a fully compliant UNIX), representing 40+ years of *nix evolution.  This history is a major part of what makes the OS so adaptable that it's used on a very large percentage of the world's web servers, virtually all supercomputers, common embedded microcontroller devices, and of course, the Raspberry Pi.  This is also a reason that many or most computer science students now end up with some significant exposure to linux.  In short, perhaps contrary to popular perception, linux is not a backwater periphery of modern computing but very close to its center.
In relation to this and the first point, it might be worth contrasting Android, which also uses the Linux kernel but has a completely different, not so unix-like, userland.

The various mainstream linux distributions, such as those used on the pi (Raspbian, Arch, Pidora), are all variants of the same OS.  They are fundamentally the same and built from the exact same pieces; the most significant differences involve the init and package management systems used.  They also customize their graphical environments, but it is worth noting that for the most part, those environments are not particular to one distribution; for example, you can use LXDE, the default on raspbian, on any other linux distro, just as you can use KDE, GNOME, etc. on raspbian if you want.

I wrote that these 3 things are important "before you go anywhere", because, with regard to learning, they will help you to understand what materials are relevant.  For example, if you are using one of the normative linux distros (raspbian/debian, pidora, arch), these are the same as they are on an x86 based desktop.  Pi users represent only a small fraction of linux PC users generally, so while I am a big supporter of this site, keep in mind there is a much larger GNU/Linux community out there (and an even bigger "unix-like" user community), and you would be wise to make use of it.
The internet is of course (...naturally, even), a great resource for programming and technical material,2 and that coupled with hands on experimentation will almost certainly be the core of your learning experience.  WRT to books, UNIX (or linux) system administration manuals are common (== easily found) and always worth looking at.
If you are going to make use of the pi remotely and have a spare partition on another computer, I highly recommend you install a linux on that and work from there.  Cygwin is something you should know about if you prefer to stick with Windows, especially if you want to do pi related programming.  You can also run linux inside another OS via a virtual machine.
Man pages are an indispensable reference.  Like a lot of people I did not at all enjoy man pages at first, but the sooner you get to like them the better.  They are the primary documentation (meaning, free from hearsay and misunderstanding, the "final authority") -- for basic commands and configuration files, and if you are squeamish about consulting them, you will end up wasting a lot of time.  When you have questions about something, quoting  something from a man page (e.g., something which has you puzzled or frustrated) is an excellent start.
WRT Linux kernel features, the official source tree includes a Documentation/ directory with a lot of useful information in it -- probably most useful via a text file search tool such as grep (and see the -R switch in the man page).  This directory is also available online.
C/C++
Not everyone is a fan of lumping these languages together, but one is an evolutionary offshoot of the other, and it is worth noting that C was developed at least partially to revolutionize the portability of UNIX, and this unparalleled lineage of portability explains linux's adaptability as well.  Many aspects of C's style have been a significant influence on most of the other widely used programming languages today. Linux (the kernel) is written primarily in C (with asm where required) as is pretty much all of the fundamental pieces of the GNU userland, which is why C is the "native" language of linux.  While you don't need to learn C to learn C++, it certainly will broaden your understanding of it.  Also, because C is so universal, higher level languages such as python, perl, and shell (which are in fact implemented in C) often "wrap" native library functions transparently, so understanding those native libraries will give you some insight there.
The ISO compliant standard C library on linux (GNU glibc) is rounded out with extensions that come, for the most part, directly from the UNIX world.  The GNU C Library Manual is a good introduction to these and system programming on linux generally.  Man pages, which cover the entire standard library plus GNU extensions, are again the primary documentation.  GNU C is also pretty much POSIX complaint, and the offical POSIX man pages are sometimes a better read than the GNU ones used on linux systems.

1. Above I use capital L Linux when referring to the kernel and small l linux for the unix-like Linux based OS, aka. GNU/Linux.  The reason for the "GNU/" is that most of the fundamental userland, including the native library, are GNU projects, and GNU as an organization is separate from Linux.
2. E.g. I think wikipedia is a near textbook quality source of concise, general CS related information (as might be deduced from my links here).
Answer: Best way to learn is by doing. Get your hands dirty with the device. If you are new to Raspberry Pi, a quick way would be to install NOOBS on your SD Card, it shall give you option to boot from Raspbian (Debian) as well.
Python is preinstalled but you can easily install C/C++ as well. If you are able to do this yourself, you can reward yourself in getting a good beginning in learning debian.
Answer: I started using Pi around 6 months ago. I've created a small media center in my house. This is what I would suggest you to do ->
1) start with installing XBMC and create a small media center in your house (there's a lot of information online specific to this topic. You need a Television in your house with a HDMI input and a SD card to install XBMC.)
2) Once that is done. Learn some basic concepts of Linux and SSH and get familiar with it.
3) Try to log into the raspberry pi using any SSH client like putty. (Logging into raspberry pi from your laptop is easy, just follow some online forums for the exact procedure. But, you need to make sure the Pi and your laptop are connected to the same router. I've a Pi connected to the router of my house by a LAN cable, whereas I SSH into Pi from my laptop on the same router through WiFi)
4) Browse through the files and plugin folders, you'll observe all of that is programmed in Python.
5) Learn some basic python, and try to understand how a plugin in XBMC works by accessing it's python scripts.
6) When you see a link/plugin is broken, you can simply log into the Pi using SSH, look at it's python code and try to fix it.
With all this, you'll achieve a lot.
You'll learn a little bit of-
1) Linux
2) Python
3) XBMC
Moreover, you'll have an awesome media center in your house on which you can watch HD movies and latest shows directly streaming on your TV.
I hope this helps. All the best :)
Answer: Although an older question, but maybe wanted to refresh new resources on the site for anyone with the same question.
https://www.raspberrypi.org/education/ is your main 1st breath of raspberry Pi literature if you want to explore it's capacity and technical reading, so is Wikipedia.
But assuming you already have an actual Pi plugged in, powered and configured ready to go in front of you, jump into https://projects.raspberrypi.org/en/projects instead for a initial gauge of what to do next. Specifically recommend doing Python training and focus on completing projects already using your Pi (https://www.raspberrypi.org/documentation/usage/python/) before you do any C++ or others since python is ready out of the box, unless you plan to focus on c++ specifically.
You can always jump out of the python learning into any other language if you feel you need a change or just prefer exploring. Once you are comfortable with a standalone software project then you can also mix in an electronics starter projects like blinky and like. https://raspberrypihq.com/making-a-led-blink-using-the-raspberry-pi-and-python/
I'm almost certain you will know exactly what you want to learn next shortly after that.

How to start working with Raspberry Pi?


How do I see who's online to my linked Gchat and Facebook Chat in Messages?

Question: I had Google Chat and Facebook Chat linked to iChat, but since I upgraded to Mountain Lion I can't see who's online through the bar that used to display along side messaging window. Any ideas?
Answer: The sidebar shows your list of open chats. When someone is offline, the text "Offline" shows under their name:

This also depends on whether you have iMessage-enabled contact information for those people — it seems that if you do, they never appear as Offline.
(Also note that the buddy list window still works well for seeing who's online!)
Answer: Under the window menu you can access all the same contact lists as before (or a unified list if you chose that within Messages preferences)
Command + [a number] is the shortcut to open/close these windows
Answer: I had the same inconvenience but then found it. It's the exact same buddy list you had in iChat:
Command + 1
Or Window - Buddies.


What are good ways to begin preparing a child for a new baby?

Question: I have a 4 and a half month old, so this won't be applicable for a while, but I would like to raise my son with the idea that he won't be an only child forever. I want my children to have a good relationship from the start. How do you prepare a toddler to be an older sibling?
Answer: One that worked well for us was for the new baby to 'give' a present to her siblings to say hi, and to let the elder ones hold her and give her cuddles from day 1 (actually from about 15 minutes old:-)
Before the birth, let them help to choose things for the baby so they feel part of the discussion.
After the birth, let them know how important their help is when Mummy and Daddy are tired - things like tidying up, helping cook etc are Big Brother/Sister jobs that the new baby can't do. This also helps them to feel wanted.
Answer: Young children (<5 years) need very little conditioning for the idea of a brother or sister. If they're socialized around other children with siblings, either in school, playgroups, or extended family, they'll learn this is a natural state. They'll just need preparation for when the little one is coming so they know what will change. Very young and it may mean they have to give up their crib or other personal effects. For older children it will mean just learning that they will have to share mom and dad's time (but they'll still have their full dose of love).
You won't plant that idea too firmly or early, though. There is always a chance that despite your intentions and efforts, he may be an only. It can be very hard to explain to a six year old why that baby brother never appeared.
Comment: I guess kids have a hard time understanding that although parents have to divide their _limited time,_ they have _unlimited love._
Comment: I have to disagree with the idea of not planting the idea of siblings just because of what-ifs.
Comment: @Christine I understand your point, but the question how much and how early do you need to prepare a young child for a sibling. Most professional guidance suggests talking about it early in the pregnancy, not months or years before. So while the "what-if" may seem like a slim chance, the benefit of starting early is equally slim.
Answer: Start early and talk often.
Talk about other people who have siblings. Talk about your siblings (if you have them).
For us, the thing that help the most was talking about the whole family relationship tree.
What is a brother, a sister, an aunt, an uncle. Explain what a cousin is, and grand-parents. Understanding that there are all these different types of family relationships helped us to set the expectation of what a brother or sister was much easier and then when they actualy came along it was simpler to transition.


Is there any biblical basis to support demonic paranormal activity?

Question: Demonic possession of course is biblical, but what about demonic paranormal activity? With some effort it's not hard to come across testimonies from Christians, and even non-Christians, telling stories of paranormal experiences, such as hearing footsteps, scratches on walls, drawers moving in and out, closets opening and closing, things flying off the shelves or walls, beds shaking, chairs moving, objects falling down, light bulbs exploding, stuff levitating, the temperature in the room suddenly dropping, horrible demonic "smell", hearing audible evil growls, etc. I'm pretty sure many of you have heard of similar experiences. Is there any biblical basis to this? Does the Bible record examples of demonic paranormal activity? Do the Scriptures support the ability of demons to manipulate objects and intervene in the physical world?
Comment: Do not know about the biblical basis for this is that well documented since this seems somewhat out of character for Biblical subject. That said the historical documentation is better well known. Just read the ***Life of St. John Vianney*** by Fr. Francis Trochu.
Answer: Most would agree that demons are fallen angels and, as such, that they share the same angelic nature as normal angels (although some would make a special distinction with the supposedly disembodied spirits of the Nephilim, but that's a topic for another question). But in any case, nobody questions that demons are instances of spiritual beings. So, in order to have an informed perspective on what the scriptures support as possible, we have to look at all the scriptural evidence for physical interventions performed by spiritual beings (demons, angels, etc.). Below are some notable examples:
1) Turning a staff into a serpent:

[Exodus 7:11,12 NIV] 11 Pharaoh then summoned wise men and sorcerers, and the Egyptian magicians also did the same things by their secret arts: 12 Each one threw down his staff and it became a snake. But Aaron's staff swallowed up their staffs

2) Scaring people and physically touching someone:

[Daniel 10:7-10 NIV] 7 I, Daniel, was the only one who saw the vision. The men with me didn't see the vision. Yet, they started to tremble violently, and they quickly hid themselves. 8 So I was left alone to see this grand vision. I had no strength left in me. My face turned deathly pale, and I was helpless. 9 I heard the man speak, and as I listened to his words, I fainted facedown on the ground. 10 Then a hand touched me and made my hands and knees shake.

3) Influencing animals:

[Matthew 8:30-32 NIV] 30 A large herd of pigs was feeding in the distance. 31 The demons begged Jesus, "If you're going to force us out, send us into that herd of pigs." 32 Jesus said to them, "Go!" The demons came out and went into the pigs. Suddenly, the whole herd rushed down the cliff into the sea and died in the water.

4) Manipulating the weather:

[Job 1:12,16,18-19 NIV] 12 The Lord told Satan, "Everything he has is in your power, but you must not lay a hand on him!" Then Satan left the Lord's presence. [...] 16 While he was still speaking, another messenger came and said, "A fire from God fell from heaven and completely burned your flocks and servants. I'm the only one who has escaped to tell you." [...] 18 While he was still speaking, another messenger came and said, "Your sons and your daughters were eating and drinking wine at their oldest brother's home 19 when suddenly a great storm swept across the desert and struck the four corners of the house. It fell on the young people, and they died. I'm the only one who has escaped to tell you."

5) Appearing visibly to people as ghosts:

[Matthew 14:26 NIV] When the disciples saw him walking on the lake, they were terrified. "It's a ghost," they said, and cried out in fear.

[Luke 24:39 NIV] "Look at my hands and my feet. It is I myself! Touch me and see; a ghost does not have flesh and bones, as you see I have."

6) Showing up physically before someone, staying in their house, eating food and striking others with blindness:

[Genesis 19:1-3,10-11 NIV] The two angels arrived at Sodom in the evening, and Lot was sitting in the gateway of the city. When he saw them, he got up to meet them and bowed down with his face to the ground. 2 "My lords," he said, "please turn aside to your servant's house. You can wash your feet and spend the night and then go on your way early in the morning." "No," they answered, "we will spend the night in the square." 3 But he insisted so strongly that they did go with him and entered his house. He prepared a meal for them, baking bread without yeast, and they ate. [...] 10 But the men inside reached out and pulled Lot back into the house and shut the door. 11 Then they struck the men who were at the door of the house, young and old, with blindness so that they could not find the door.

7) Interacting with physical water:

[John 5:4 KJV] For an angel went down at a certain season into the pool, and troubled the water: whosoever then first after the troubling of the water stepped in was made whole of whatsoever disease he had.

8) Having relations and procreating with physical women ((*)Note: this interpretation is disputed by some):

[Genesis 6:1-4 NIV] When human beings began to increase in number on the earth and daughters were born to them, 2 the sons of God saw that the daughters of humans were beautiful, and they married any of them they chose. 3 Then the Lord said, "My Spirit will not contend with humans forever, for they are mortal; their days will be a hundred and twenty years." 4 The Nephilim were on the earth in those days—and also afterward—when the sons of God went to the daughters of humans and had children by them. They were the heroes of old, men of renown.

In light of this whole range of possible interactions with the physical realm by demons, angels and spiritual beings in general, stories of demonic paranormal activity sound very much compatible with Scripture and unsurprising to be honest.
Comment: Bene, bene, bene ***Doctor Corpore***! It is seemingly always a question of interpretation.
Comment: Your last point/(8), I would not include. Translation is not clear here. See my answer to this question: [**Were all Nephilim evil?**](https://christianity.stackexchange.com/a/70936/25495)
Comment: @KenGraham - thanks for pointing that out, I added a short note referencing your answer
Comment: @spirit realm, it's a very good point you make by comparing the activity [miracles] of good angels with demons.  I wouldn't include # 5 because this is explicitly stated in Matt 24 and Luke 14 as Christ - so it doesn't fit the category of angels or demonic paranormal activity.
Comment: @Tennman7 - although it was Jesus in both cases, those passages show that the visibility of ghosts was a real possibility, hence the need by Jesus to clarify that he **was not** a ghost.
Answer: Is there any biblical basis to support demonic paranormal activity?
Does the Bible record examples of demonic paranormal activity? Do the Scriptures support the ability of demons to manipulate objects and intervene in the physical world?
The short answer is maybe at best. And then only perhaps indirectly!
There is no direct biblical support to suggest that demons are capable of making footstep noises, scratching on walls, moving drawers in and out, opening closets and then closing them,  making things things fly off the shelves or walls, beds shaking, chairs moving, objects falling down, light bulbs exploding, stuff levitating, the temperature in the room suddenly dropping, making horrible demonic "smell", creating audible evil growls or other paranormal activity.
The Devil and his minions are in a way comparable to a virus (Covid-19, if you wish) or electricity. All three are seemingly invisible, yet could be potentially dangerous to mankind, if circumstances are right.
There is an invisible realm in our world. Let us always recall the words of St. Paul:

12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. - Ephesians 6:12

St. Paul admits that the forces of evil rule the air in which we live live, thus the possibility of evil manipulating the physical sphere in which we live does not at all seem an outright impossibility.
Again St. Paul teaches thus (Admittedly, both interpretation and translation of the Sacred Texts plays a big part here):

2 And you, when you were dead in your offences, and sins,
2 Wherein in time past you walked according to the course of this world, according to the prince of the power of this air, of the spirit that now worketh on the children of unbelief. - Ephesians 2:1-2

We can see the work of Satan and his hatred for the holiness of true saints in the person of Job. Satan created a storm that killed Job's family, yet Job did not sin by blaming God.

9 Satan replied, "Would Job worship you if he got nothing out of it? 10 You have always protected him and his family and everything he owns. You bless everything he does, and you have given him enough cattle to fill the whole country. 11 But now suppose you take away everything he has—he will curse you to your face!"
12 "All right," the Lord said to Satan, "everything he has is in your power, but you must not hurt Job himself." So Satan left.
13 One day when Job's children were having a feast at the home of their oldest brother, 14 a messenger came running to Job. "We were plowing the fields with the oxen," he said, "and the donkeys were in a nearby pasture. 15 Suddenly the Sabeans attacked and stole them all. They killed every one of your servants except me. I am the only one who escaped to tell you."
16 Before he had finished speaking, another servant came and said, "Lightning struck the sheep and the shepherds and killed them all. I am the only one who escaped to tell you."
17 Before he had finished speaking, another servant came and said, "Three bands of Chaldean raiders attacked us, took away the camels, and killed all your servants except me. I am the only one who escaped to tell you."
18 Before he had finished speaking, another servant came and said, "Your children were having a feast at the home of your oldest son, 19 when a storm swept in from the desert. It blew the house down and killed them all. I am the only one who escaped to tell you."
20 Then Job got up and tore his clothes in grief. He shaved his head and threw himself face downward on the ground. 21 He said, "I was born with nothing, and I will die with nothing. The Lord gave, and now he has taken away. May his name be praised!"
22 In spite of everything that had happened, Job did not sin by blaming God. - Job 1: 9-22

It is obvious, that the demons can to some degree manipulate the physical world we live in and they do not need the intermediary of a human person to communicate to us. There are countless references of the good Angels speaking to people in both the New and Old Testament.  The Annunciation is just one example:

29 Mary was greatly troubled at his words and wondered what kind of greeting this might be. 30 But the angel said to her, "Do not be afraid, Mary; you have found favour with God. 31 You will conceive and give birth to a son, and you are to call him Jesus. 32 He will be great and will be called the Son of the Most High. The Lord God will give him the throne of his father David, 33 and he will reign over Jacob's descendants forever; his kingdom will never end." - Luke 1:26–38

We thus see that the Angel Gabriel is trying to keep the Virgin Mary calm during the angelic visitation.
Now for Satan or anyone of the demons, they do not care about mankind one iota. They simply want us all to go to hell and join them forever.
The soul that is truly arduous in holiness and genuinely seeks the conversion of sinners is not going to get such a warm welcome from the Devil and his Legions. If you steal his prey, it makes logical sense he would try to scare the hell out of you. There is no real difficultly for me to imagine to Devil making all sorts of noises to make someone think they are going crazy and being drawn into despair.

If I speak in the tongues of men or of angels, but do not have love, I am only a resounding gong or a clanging cymbal. - 1 Corinthians 13:1

Satan will do all it takes and make as much noise to interfere in his plans to ruin mankind. The Devil loves not, thus he is the clanging cymbal par excellence.
What exactly were the manifestations of paranormal activities of the demons is not listed in Sacred Scriptures, but we must deduce that some truly existed. The story of the seven sons of one Sceva in Acts 19: 13-17 fits in well here:

13 Then certain of the vagabond Jews, exorcists, took upon them to call over them which had evil spirits the name of the Lord Jesus, saying, We adjure you by Jesus whom Paul preacheth.
14 And there were seven sons of one Sceva, a Jew, and chief of the priests, which did so.
15 And the evil spirit answered and said, Jesus I know, and Paul I know; but who are ye?
16 And the man in whom the evil spirit was leaped on them, and overcame them, and prevailed against them, so that they fled out of that house naked and wounded.
17 And this was known to all the Jews and Greeks also dwelling at Ephesus; and fear fell on them all, and the name of the Lord Jesus was magnified. - Acts19:13-17

What all transpired during this exorcism, we just do not know. St. Luke only recounts a rough outline, in order to keep our imagination healthy. There is no need to dwell on the morbid. Obvious light bulbs did not explode as they were not invented yet. Were there other manifestation of paranormal activity? Certainly, but Scripture remains silent on this issue.
Another time Jesus Restores a Demon-Possessed Man who lived amongst the tombs and "night and day among the tombs and in the hills he would cry out and cut himself with stones."

5 They went across the lake to the region of the Gerasenes.[a] 2 When Jesus got out of the boat, a man with an impure spirit came from the tombs to meet him. 3 This man lived in the tombs, and no one could bind him anymore, not even with a chain. 4 For he had often been chained hand and foot, but he tore the chains apart and broke the irons on his feet. No one was strong enough to subdue him. 5 Night and day among the tombs and in the hills he would cry out and cut himself with stones.
6 When he saw Jesus from a distance, he ran and fell on his knees in front of him. 7 He shouted at the top of his voice, "What do you want with me, Jesus, Son of the Most High God? In God's name don't torture me!" 8 For Jesus had said to him, "Come out of this man, you impure spirit!" - Mark 5:1-20

Once again, allow me to use Scripture to relate the possibility of the good Angels helping us to hold that the opposite may also be true in our lives.
Let us recall the story in St. John's Gospel how the Angel of God stirred the water in the Pool of Bethesda! Now if the Angel of God could do good this way, what stops Evil from intervening in our lives to create havoc and fear.

For an angel went down at a certain time into the pool and stirred up the water; then whoever stepped in first, after the stirring of the water, was made well of whatever disease he had. - John 5:4

If the Angel of God can stir the waters to heal, can not the Devil shake beds, etc. to scare the wits out of us...

Nightly Monsieur Vianney's rectory was the site of a terrifying cacophony: scurrying and gnawing rats, the sound of pounding nails, and howling wind.  When the noises failed to trouble the holy Curé, the Devil turned over furniture, smeared excrement on the doorway, and set the priest's bed on fire. To this last effort, Vianney responded, "The wretched fiend.  He has not been able to catch the bird, so he has burnt the cage."  - The Devil's Most Effective Foe

Saint John Vianney's Bed, burnt by the devil.
Answer: "Does the Bible record examples of Demonic paranormal activity? Is there any biblical basis for this- [light bulbs exploding, things levitating, the temperature in the room suddenly dropping"]

If you mean like these specific examples - then the answer is No.
" Does the Bible record examples of demonic paranormal activity - the ability of demons to intervene in the physical world?" then the answer is Yes! Assuming that you mean besides demon possession, demonic paranormal activity is demonic oppression, or demons acting to affect the physical world, including animals and people's health, and even do false miracles.

Demonic activity in scripture = categorically yes. Moving drawers in dressers,and lamps falling over, a horrible sulfer-like smell= No.
It is not uncommon for people in ministry to have witnessed demonic activity and it is also clearly supported in scripture.
A very good way to summarize this is that as Christians, is is not possible to be demon possessed, but they can be oppressed - under demonic attack.  Satan is still at work around the world, and the Bible says that he "walks about,like a roaring lion, seeking whom he may devour."

8 "Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. 9 Resist him, firm in your faith, knowing that the same kinds of suffering are being experienced by your brotherhood throughout the world." - I Peter 5:7-9

As the person stated in the opening question, there is plenty of evidence all through the Bible of people being possessed, and Christ and the disciples driving out demons, but is there any evidence of Christians being oppressed?
Yes, as a matter of fact, there is.
One example is Job. Scripture says Job was blameless and upright.

The fuller context in Job 1:1 is, "This man was blameless and upright; he feared God and shunned evil." So, the description of Job being "blameless and upright" is linked to the fear of God and the avoidance of evil. The parallelism can be seen like this:
Blameless/upright. God-fearer/one who turns from evil. In short, Job was "blameless and upright" in that he was a man of integrity who trusted in God as his redeemer (see Job 19:25), sincerely worshiped the Lord, loved his family, and was consistent in his walk with God." - What does it mean that Job was blameless and upright?

God allowed Job to be tested, even physical harm, but God limited the effect - the level to which the attacks could be from Satan and in the end, all was restored to Job.
It the Old Testament, we see demonic paranormal activity through the witch of Endor, when she used demonic forces to summon the dead for Saul.
"In the Old Testament, (I Samuel 28:3-25) the witch of Endor is a woman Saul consulted to summon the spirit of prophet Samuel in the 28th chapter of the First Book of Samuel in order to receive advice against the Philistines in battle after his prior attempts to consult God through sacred lots and prophets had failed."
Then in all three of the synoptic Gospels, -Matthew, Mark and Luke- we also see demonic paranormal activity - demons entering into an entire herd of swine, and they all rushed over a cliff and died: When Jesus Christ was tempted by Satan, Satan asked him to do certain things which he denied. But in Matthew 8 the demons wanted Jesus to drive them into pigs and he did so. The herd then ran into the water and drowned. Why did Christ deny one request of the enemy but accept another?
Then, again, we see another example of demonic or satanic oppression against Paul. Satan relentlessly attacked Paul in an effort to hinder or stop Paul's ministry.

7 "And lest I should be exalted above measure by the abundance of revelations, a thorn was given me in the flesh, a messenger of Satan, to torment me, lest I be exalted above measure. 8 I asked the Lord three times that this thing might depart from me. 9 But He said to me, "My grace is sufficient for you, for My strength is made perfect in weakness." - 2 Corinthians 12:7-9

We can't say with certainty what this was exactly, or all the extent of this demonic oppression, but many scholars say that it was most likely poor vision, and this is due to him being struck blind temporarily, in his famous conversion on the road to Damascus. Later in his life, he even says in his epistles, "see what large letters I write with my own hand..." to denote his personal love and care for the believers in the early churches.
This is also consistent with teaching in different protestant denominations - Church of God Holiness, Bible Methodist, some Baptist and some Nazarene churches as well as some Evangelical Free Churches of America.
Another example is the terrible persecution of Christians in China, Russia under communism and other communist countries, and the many stories of Christians who were persecuted, tortured and even Martyred in "Fox's Book of Martyrs".
A personal friend of the family and former missionary to Haiti witnessed the effects of witchcraft and saw people become sick and experience physical manifestations from voodoo dolls, and were then healed.
Another person I heard  recounted a story of sickness and multiple bizarre physical issues related to an occultic object in their home. A pastor explained that the object had occultic connections and they burned it, and prayed over the person and they recovered fully.
The point is that sometimes these are tests, allowed by God, and other times, we can unintentionally give Satan a foothold, or open up doors in our lives that give the enemy places to attack, such as through things like Tarot cards, and Eastern religions, Yogo, etc.  There are testimonies of people who experienced demonic paranormal activity or oppression as a result of accupuncture needles, which are sometimes prayed over by those who practice this.
Here is another source that explains the concept and differences between satanic attacks or oppression and demonic possession: CHRISTIANS AND DEMONIC ACTIVITY TODAY
Comment: I do not think this actually answers the question. The OP would like biblical support from the Scriptures to support to the concept of what we say in modern times as **demonic paranormal activity**?
Comment: @KenGraham - I think I found a possible biblical basis. Ex 7:11,12: *11 Pharaoh then summoned wise men and sorcerers, **and the Egyptian magicians also did the same things by their secret arts: 12 Each one threw down his staff and it became a snake**. But Aaron's staff swallowed up their staffs.*
Comment: Downvoted. You write "Does the Bible record examples of demonic paranormal activity - the ability of demons to intervene in the physical world? Then the answer is Yes!" But then you don't actually give an example of one.
Comment: Hello DJ. I don't understand.  I gave 4 examples.  Witch of Endor with Saul- she summoned the dead spirit of Samuel. Then the Demonic paranormal activity of the pigs, and the demonic oppression of Job, and the messenger of Satan that affected the physical health of Paul. So you think these people were demon possessed?  I'm not being sarcastic- i don't understand- do you not consider these things the physical world? I also gave the scripture texts. What better examples do you have in mind?


Does Iridology work?

Question: Iridology claims that it's practitioners can diagnose various illnesses via looking at the eyes of patients.
Is there evidence that supports or debunked their claims?
Comment: Liver failure. With a Yellowing of the eye.
Comment: well, clearly you can diagnose eye pathologies like that :-)
Comment: Morbus Wilson and juvenile hypercholesterinaemia would be some examples of diseases that you can diagnose from the iris, at least tentatively. Yellowing of the eye as rjstelling suggests occurs in the sclera, not the iris -- but sure enough that is a good indicator of bilirubin. Also, petechiae are something you probably know from one of the many crime tv series. However, one should not mistake something like "iridology" as a panacea. TCM uses tongue diagnostic to the similar extent, and while some diseases can be diagnosed very well like this, other claims are purely ridiculous.
Comment: Why aren't these answers?
Comment: @Dogmarog: You only should post as answers what you think is going to be voted up and be accepted. If what you intend to say is only a partial answer, it should be a comment.
Answer: No, according to an evaluation in 1979:

Iridology had no clinical or statistically significant ability to detect the presence of kidney disease. Iridology was neither selective nor specific, and the likelihood of correct detection was statistically no better than chance.

A systemic review undertaken in 1999 also concluded iridology does not work:

The validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.

However apart from scientific studies a skeptic may be satisfied that iridology does not work by a simple observation: if the practice was as effective as claimed, naturopaths would use iridology as the initial step in diagnosing and treating patients without requesting further information. It would be a superb way to differentiate their services from mainstream medicine and would quickly impress patients.
However this does not happen. Natural health practioners, like doctors, generally require new patients to complete a survey outlining their medical history, diet, and present complaints. The introduction of iridology into a natural health session may be more useful as a secondary aid in medical theatre, creating the sense that the practioner has additional powers of observation that ultimately lend more weight to the lifestyle instructions they deliver to patients.
Answer: As for iridology specifically...
There are many conditions which can be diagnosed by looking at the eye, and for the most part, they are only conditions which affect the eye.  Pupillary response can be measured to assess brain function and jaundice can be detected by looking into the eye.  However, that is not the claim here.  It is the sclera (white part) which becomes jaundiced, not the iris, and it is the pupil not the iris which becomes the indicator of brain function.
There is also an argument which can be made, stating that since the PAX6 gene codes for the formation of the iris and also the frontal lobe, there could be a theoretical link between the iris and one's personality, but only very, very theoretically.  There is absolutely no proposed link between disease in one organ and an expression in the already genetically coded external appearance of the iris. Nor is there an idea of any way in which there could be such a link.
Studies....
You can check out a link here (it's only an abstract), regarding what is generally thought of having to study pseudoscientific claims. Here is one done stating iridology is ineffective.
Another general abstract stating its ineffectiveness.
Here is one showing it is ineffective in looking for gall bladder disease.
Aside from that, I don't believe that there are many more peer-reviewed, legitimate published studies on-topic.  I would suggest you look into genetics, anatomy and physiology for an understanding of why the claims of iridologists do not even begin to meet the burden of proof.
Regarding pseudoscienctific claims in general....
Such claims are the reason boards like this need to exist and the skeptical community needs to keep at it.
In medical and pharmaceutical research time, talent, and funding are all very limited.  Simple ethics dictate that these limited resources are are allocated to the areas with the most potential for benefit. Put simply: designing, implementing and testing ideas with a valid base in science in order to do the most good.
Most professionals realize that it is unethical to waste limited resources on claims
which don't even merit consideration because they are simply ludicrous and based on imaginary principles.
In short, if it can be disproven with only a basic knowledge of human anatomy and physiology, or doesn't have a reason to be taken seriously in the first place, it is usually (and rightly) dismissed out of hand and without comment by the professionals.
As a result, it can sometimes be hard for the public to find published studies which EXPLICITLY DISPROVE pseudoscientific ideas.  Sadly, people who sell these products and push these ideas exploit the knowledge and ethics of the scientific community, knowing that real scientists will not waste the time and resources to refute the claims they make. So, while it may sometimes be hard to find an accurate layman's debunking of a specific claim, this in NO WAY lgitimizes it, because the burden of proof lies on the one making the claim.
Comment: We don't live in a world where the pharma industry sets their agenda by what produces the greatest benefit. Curing Malaria would have a bigger benefit than curing baldness, but that pharma still invests very much money into curing baldness. If an idea is unstudied it's not clear whether it works or whether it doesn't.
Comment: @Monkey Tuesday Why don't you simply flip your "on iridology" section and your "on pseudoscientific claims" section? Yours is a long answer, and as I was skimming through I considered skipping past it because it wasn't at first answering the question...till later. At the same time, you make a good point in those first paragraphs.  May I suggest introducing the meat first, than digressing later?
Comment: I felt it was important to explain why there aren't many real studies done on pseudoscientific claims, in order to explain why there aren't many studies done on THIS particular claim.  However, you make an excellent point. I hope it's easier and more accessible after the edit.  Thanks.
Comment: I was speaking in generalitites, only in order to give a very simplistic background for why there may be a lack of research done on a claim. It was admittedly a digression (and possibly completely unnecessary) and by no means the focus of my argument.  I could have been more specific when I said "good", but whether you interpret that word to mean either "beneficial for humanity" or "profitable" there is still very little value in debunking pseudoscientific claims.  I feel this holds as a general statement.
Comment: Also, I understand the spirit of your complaint about pharma, and agree for the most part. But your examples are weak.  First of all, a sucessful cure for malaria came well before any "cure" for baldness (if there is such a thing).  And I assume by referencing malaria, you are calling attention to the fact that it kills millions while a sucessful cure is available in most western countries.  Of course this is tragic, but it is a problem of distribution, economics and politics, not research.
Comment: Sorry for the length, but one more thing:  You do realize that minoxidil (a common drug for male pattern baldness) was intially intended to treat high blood pressure.  Hair growth was just a side effect.  Similarly, viagra was intially intended to treat angina and hypertension.  Very sorry to pick at your comment, it's just that I think you made a good point about resource allocation, but in the future should back it up more effectively.

Does Iridology work?


Do the Rod of the Pact Keeper and Wand of the War Mage stack?

Question: Can a warlock hold a +3 Rod of the Pact Keeper in one hand and a +3 Wand of the War Mage in the other and gain +6 on her spell attacks?
Answer: Yup
Both require attunement, but you've got three attunement "slots" so there's no problem there.
One requires the wielder be a Warlock, the other just requires the wielder be a spellcaster. So no problems there.
Looking elsewhere, the only conflict we might run into would be "Multiple Items of the Same Kind" (DMG p.141). But that's directed at things—like layering two pair of gloves or boots—that would be physically incompatible. Holding two one-handed objects really doesn't seem to run afoul of it.
If this seems overpowered, just remember what it's "costing" the warlock: two of her three attuned items, along with whatever it took to get two very rare magic items, plus a free hand for material components. And it only benefits her spells which require attack rolls. It's a lot, but it's not worse than a rogue who got her hands on a +3 longbow and a Manual of Quickness of Action. The point is: if your game's got very rare magic in enough quantity for a single character to grab two harmonizing items, that's going to be a lot of power.
Comment: Wouldn't you be able to use the rod (as an arcane focus) for most spells without a costed material component? Which means most of the time you wouldnt need a free hand for material components?
Comment: @BenGardner if your GM's good with the rod being a focus. (Or wand.) That's not obviously how the items are written, though. See https://rpg.stackexchange.com/q/129961/23970 for more on that.
Answer: Actually, they do stack, but only under certain circumstances. There must be a material and somatic component to the spell, and the spell's component MUST be something that an arcane focus can replace. In addition, it must be a warlock SPELL cast, not just a spell cast from a warlock slot (although, it can be a warlock spell cast from another class slot, such as Sorc/Bard/Pally, if the character is multi-classed.
Comment: Why must there be a material and somatic component?


Magento product Issue

Question:
Possible Duplicate:
Magento products will not show in category

I am adding products in magento from IMport facility and I add them successfully in backend but they are not visible in frontend.
Can someone please tell me how to solve this problem??
I did everything change some values in that product or some stuff like this.
Can someone tell me how to do that?
Answer: Make sure those products;

are assigned to a website
are set to in stock and have a quantity (or disable stock)
are enabled

Magento product Issue


Regarding a deleted post

Question: I posted a question on mathoverflow. It was regarding a counter example that I had found. Later I realized that I should not have done that and deleted it. I am writing a research paper on how I constructed the example. Do I still have rights for my example?
Comment: I think I found my answer here https://meta.mathoverflow.net/questions/950/who-owns-my-mathoverflow-posts. Please correct me if I am wrong.
Comment: If you had no feedback to your question you can do as if nothing happened.
Comment: Ycor may be right.  If it were me in your situation, I would ask for an email (or a letter from their legal team) from a Stackexchange representative to make sure things were OK on their end.  Gerhard "Covering Your Assets Is Smart" Paseman, 2018.04.15.
Answer: You can't copyright an idea, only a text.  Posting something here has a copyright effect on the specific text you post, but a paper with the same ideas (but presumably a lot more exposition) would not be affected.
Comment: Not sure I understand your question.  The links you posted describe the copyright situation.  That covers the text.  Legally, as long as they don't directly copy text that is copyrighted, anyone can write about or use any ideas they want, no matter how they heard about it.  Academic norms say that they need to properly attribute ideas that are due to other people, but those norms are not part of the law.  They are enforced through custom and social pressure; people who violate them risk being ostracised from the academic community.
Comment: You mean. Anyone can use it because it was on MO?

Regarding a deleted post


Comparing acidity between groups

Question:

I tried to do this using the stability of conjugate base. I can see (2) will be most stable due to resonance however my confusion lies in (1) and (3).
While in (3), the negative charge is unstable but in (1) I can't tell if it will take part in resonance because in pyridine the lone pair doesn't take part in resonance so is the same thing happening here?
Comment: Pretty much. If 1 is deprotonated, the resulting lone pair is perpendicular to the pi system of the ring, therefore only indirectly resonance stabilised (i.e. the ionic configuration would contribute more). This position should be a bit more acidic, because nitrogen is a bit more electronegative than carbon.
Answer: The answer should be A.
Since 3 is vinylic hydrogen, therefore it is least acidic.
Both 1 and 2 are allylic and are at the alpha position with respect to the carbonyl group.
Nitrogen is quite electronegative, therefore hydrogen 1 is more acidic than hydrogen 2. Hence the result.
Answer: Answer - A
Explanation -
3 is least acidic as the negative charge developed after removal of hydrogen atom will not take part in resonance like other acidic hydrogens marked.
Both 1 and 2 will be resonance stabilized after removal of acidic H+ but 1 is more stable than 2 because the negative charge developed will be on Nitrogen atom which is more electronegative as compared to carbon. More electronegative atom would like to have electrons to complete its octet.
So, the order will be 1>2>3

Comparing acidity between groups


How to overcome lack of SQL Agent Job Scheduling Service on SQL Express Edition?

Question: We want to schedule sql database backups like you are able to do with SQL Agent Job Scheduling Service.  Is there any way of doing this backups on the SQL 2005 Express edition?
Answer: I've worked around this in two ways:

You can use Windows' Scheduled Tasks to execute a script using SQLCMD.
If you have other SQL Servers that are not the Express edition, you can create maintenance plans on those servers that point to the Express server.
Answer: You can script the backup and use a scheduled task to do it.  Here's an example of what to use as the command for your task using the osql command line tool (or what to put in a batch file):
<code>osql -s myserver -E -Q " BACKUP DATABASE MyDB TO DISK = 'C:\SQLBackups\MyDB.bak'"
</code>
Here is the MSDN reference page for the SQL 2005 BACKUP statement if you need to incorporate more options to your backup than the very basic statement above.
Comment: Hello squillman.  Your command works, but when I restore the file MyDB.bak it will bring all tables, store procedures, security settings, but the login for the sql engine is not mapped.  Any idea on how to bring the security settings on the engine itself?
Comment: If you're restoring to the same instance that the backup was taken from then the db security should map just fine after a restore.
Answer: I had this a problem a few years back and have been using the simple batch file and sql script ever since.
i wrote a post covering it here with included scripts and walkthrough:
http://www.diaryofaninja.com/blog/2011/02/14/howto-quick-amp-dirty-sql-express-scheduled-backup
basically i do the following:
- write a stored procedure that backups up a specified database
- write a sql script that calls this for each of the databases i want to backup
- call the above script using sqlcmd.exe using a scheduled task
this allows me to choose when it happens on a schedule and run different databases when i want
you can then use a scriptable ftp client like WinSCP (http://winscp.net/) to create another schedule that uploads the backups using FTP or SFTP (much more secure).
Answer: See here:
SQL Server 2008 Express - "Best" backup solution?
Answer: You can use external backup software like Cobian Backup for scheduling and compressing.
For the database backup itself, one option is to use ExpressMaint
More answers here:
https://stackoverflow.com/questions/487675/how-can-i-schedule-a-daily-backup-with-sql-server-express