What should I look for in a new kitchen knife set?

Question: We've had the same knives for a very long time now, and we need a new set. What should I look for (or avoid) in a new kitchen knife set?
Comment: If you have good knives that are just getting old, you may want to find a [knife sharpening service](http://cooking.stackexchange.com/q/11686/67) and have them put a new edge on the knives.  If it was a set of 20+ knives for under $40, it's likely not worth it, though.
Comment: highly related : http://cooking.stackexchange.com/q/184/67
Comment: Do you like your current set?  What do you like/dislike about it?  Is your current set a nice one?  Are any of the knives damaged?
Answer: Typically, you don't want to buy a 'set' of knives.  You're better off buying the knives that you specifically want.  Often, you'll want to get a mix of knives from different manufacturers, so that you can get the best knife for each purpose.
As for what to look for ... I'd have to say that the main issues these days are weight, handle, and how the knife is made:

Most knives should balance near the front of the handle.  If it doesn't, you'll end up doing  more work at the wrist to keep the knife in control, which will tire you out.  (exceptions are small paring knives, cleavers, and maybe exceptionally long slicers).
The blade should be full tang.  This means that the blade continues all the way to the end of the handle, giving it a better connection to the handle while improving the balance.
The handle should be comfortable in your hand.  This will of course vary per person, as we all have different hand sizes.
The handle shouldn't be too slippery.  If it is, you increase the chance of cutting yourself.
You should avoid ceramic blades unless you're specifically going to be cooking a lot of food that will discolor when cut by steel.

Now, there are some issues that are personal choice:

Most home chefs should avoid carbon steel blades.  They have their advantages, but they need extra maintenance or they'll rust.  If you didn't grow up using them and are used to immediately cleaning & possibly oiling your knives and can sharpen your own or have a reasonably priced sharpening service nearby, I'd recommend steering clear of them.
Many people prefer forged vs. stamped blades.  Although the sign of a forged blade used to be the bolster (the thick bit of metal just before the handle), newer manufacturing techniques can add a bolster to a stamped blade.  Stamped blades are thinner and more flexible, which is an advantage in boning knives.  They also tend to be considerably cheaper, which is a huge advantage when you're starting out.  Not all stamped blades are bad; I believe that the the Victorinox Fibox chef's knife has won America's Test Kitchen's round of tests.  On the high end of forged blades are folded blades, which can be quite expensive but hold a great edge.
Knives for slicing should be fairly heavy.  They shouldn't be cleaver-heavy, but you want the weight of the knife to do the work, and not have to be pressing forward with your wrist as you slice.  But if you're going to be torting cakes, or other cases where you're slicing horizontally, you want the slicer to be much lighter.
The angle of the blade affects how sharp it is, but also how often it needs to be sharpened (aka. 'edge retention').  A very small angle creates a very, very sharp blade, but if you nick a bone or something hard, it's more likely to be damaged.  Even just leaving the knives in the sink is risky with some exceptionally sharp knives  (the weight of the knife itself can break off the tip).  Japanese knives tend to be a smaller angle than European blades, but some of the European manufacturers have started putting out sharper knives.  If you have the budget, you may want a variety of angles (a small angle for vegetables, a wider angle for meats)

These are all general characteritics.  It's take much longer to go into details about each type of knife.  See for instance What should I look for in a good, multi-purpose chef's knife? .  Serrated knives are getting trickier, as there are now different types of serrations (regular, micro, wavy, etc.); even micro serrated blades (eg, Ginsu) have their advantages.
Update: I forgot to mention the personal choice 'granton edge' (dimples) or holes along the side of the knife near the cutting surface.  It can reduce the amount of drag that you get when going through solid but moist foods (apples, firm cheeses, etc.) by breaking the adhesion between the food and the blade.
Also, when it comes time to buy knives, consider asking at the store if they'll allow you to test the knives; bring some carrots and apples just to get a feel for how the different knives feel in your hand when actually cutting.  (if they won't allow you to actually cut something, they might still let you try chopping and other tasks on an empty cutting board.
Comment: 100% agree.  Not buying a set also allows you to buy better knives: buy one or two to start with, then add one or two a year or as you can afford them.  That's how I ended up with my nice 'set' of Shun knives - one or two a year, particularly when I find sales, makes a $100/knife set a lot more affordable.
Comment: I have to agree with @JoshCaswell--the main thing I'd add to this answer is whether you want bolsters, particularly if you sharpen yourself. I can live with lots of other annoying aspects in knives, but one thing I can't stand is a dull knife. And the only way to keep it sharp is to do it yourself regularly; sending them out frequently is too expensive and annoying for me.  Full bolsters are a huge pain for sharpening, and they serve no useful purpose - they could be shorter and still provide the balance Joe mentions, but few knives are made that way. So I almost always look for no bolsters.
Comment: Far from being a mark of quality, bolsters are actually a disadvantage to my mind, since they prevent easy sharpening of the full length of the blade. As the knife gets older, you end up with a hump at the near end. (I actually filed the bolster flat on my otherwise-favorite slicer.)
Comment: @JoshCaswell : it can be a mark of quality while still being a disadvantage in some aspects.  Personally, I typically tend to prefer the weight and balance that the bolster gives; if you have to grind if down for sharpening purposes, I'd take down the bare minimum necessary, only thinning it near the blade itself.
Comment: Also, it should be noted that full bolsters are only generally a mark of quality in traditional German-style knives.  Top Japanese knives (the handmade ones, but also the better mass-produced ones) rarely have them, and more manufacturers, even traditional European ones, are using them less in some sets.
Answer: Don't buy a set. You've had a set for a while, so you know which knives you gravitate to. Spend your money there. Don't waste your money on knives you don't use 'cause they look nice in the block.
Comment: I totally agree here. Some people are paring knife people who never touch a chefs knife. Some people never debone meat and have no need for a specialized blade for that purpose. Some people never use a cleaver. Buy the knives you want to use. Personally, give me a chef's knife and a bread knife and I'm set.
Comment: You wouldn't, for example, ask them to keep their current set if it was a Ginsu or similar stamped-blade set since those cannot be reliably resharpened or if the knives were of poor quality and the handles are all cracked...many reasons why buying a new set is perfectly valid.  And you did not answer the question.  The question was not "should I replace?"
Comment: They could be wanting to replace their set for any number of reasons...you can't simply assume they just "want" a new set.
Comment: @jbarker2160 I wouldn't ask them to keep anything. I was answering the question as written.
Comment: This may or may not answer the question - it's actually hard to tell because the question isn't totally clear. The OP asks "what should I look for (or avoid) in a set?" which could be interpreted as either "what materials/characteristics" or "what knives". If it's the latter, as I suspect it might be, this is a completely reasonable answer, although I'd probably take out the "don't buy a set" sentence.
Answer: America's Test Kitchen did a show on knife sets recently, and reported similar findings to what has already been noted here by the other commenters.  I am only including this as it is technically a set, but you simply buy the components based on their own merit and not what the manufacturer is trying to get rid of/sell you.
Per America's Test Kitchen:

Wusthof Classic 3.5" Pairing Knife: $40
Victorinox 8" Chef's Knife: $30
Wusthof 10" Bread Knife: $120
Victorinox 12" Slicing Knife: $58
Victorinox 6" Boning Knife: $20
Shun Kitchen Shears: $70
Bodum Bistro Block: $50

http://www.amazon.com/Cooks-Illustrated-Kitchen-Carte-Knife/lm/R27FG2C1FMTA16


How to "fill" a cake made from a cupcake recipe

Question: I have several cupcake recipes.  I know it's easy to convert to a cake (just adjust baking time and figure out correct pan size).  My question is many of the cupcake recipes have a filling that is (for the most part) just sort of stabbed into the baked cupcake using a squeeze bottle. These fillings are usually between artificial maple syrup and pudding in consistency/thickness.  If I want to use the filling, how would I incorporate it into the cake other than repeatedly "stabbing" the cake in various places?  A google search only tells me to tort the cake, but I'd like to leave it in a single layer if possible (plus I don't think the cupcake fillings would hold up to be filling layer in a layered cake).
Comment: If it's thick, I'd slice it and fill it ... but don't overfill, or you can create a slip-plane where the cake won't hold together any more. For the syrups, poking with holes and letting it soak in is fairly common in cake recipes.
Comment: Joe, the fillings aren't thick enough to create a layer.  Plus, I'd like to have them as a single layer cake if possible.
Comment: You might be able to use it as a glaze on top of the cake, but then you might have difficulty getting any frosting to adhere well.  (you could probably still pipe it out of a bag, though).  If the glaze doesn't want to stay in place, you can either start off by piping a ring of frosting on the outer edge, or trying to find a 'mary ann pan'
Comment: Joe, that might work.  I could spread it over the top of the cake while it's still warm and wait until it's cool to frost.  I could probably use my angel food cake cutter to poke lots of holes to encourage it to soak in a little better.
Comment: if you can't get in far enough with the angel food cake cutter, my mom would just poke her cakes repeatedly with a skewer when she was trying to get syrups or alcohol to soak in.
Answer: A syringe (or baster, but a syringe will be better) A LOT of holes, and frosting to hide the holes (though they will be pretty small if you use a syringe.)
Given the comment that  "I don't want it to be like several filled donuts joined together where it's not consistent" in combination with a refusal to consider layering it, you need

a dense pattern of holes and
a measured amount of filling in each hole.

So, for a 9x13 pan, you might be looking at 8x12 = 96 holes an inch apart, starting 1/2 inch from the edge, each filled with 1/96th of your total amount of filling. Adjust as needed for other size cakes and how well an inch apart suits your idea of "consistent" - you could go to 17x25 holes 1/2 inch apart and 1/4 inch from the edge, but it's going to be rather tedious.
Or you could TRY a more cake-centric approach - half the batter, the filling, half the batter, bake. It might fail miserably, it might "work" for some value of "work," it might require changing the filling to get a better value of "work." Certainly marble cakes and pudding cakes do things of this nature at the batter stage before baking.
Answer: Even in industrial baking, pastries are typically filled by poking a hole in the pastry and filling them by hand. At least this was my experience with some equipment design provisions my company made for a prominent Midwestern U.S. donut factory. Your best bet is likely finding a way to conceal the hole rather than avoiding it.
Comment: If a full size cake has a filling, I've only seen it made of separate layers, with the filling smeared on the layers. I've only seen injection used for baked goods you eat by biting pieces off, never in ones large enough to be cut in portions.
Comment: I've never seen an industrially made full-size cake filled through a hole. Maybe it's just not usual here, but I can imagine that it's just not done.
Comment: How do you normally see it done?
Comment: I agree with rumtscho.  Plus I would need several holes through out the cake where I'm adding filling.  I'm not worried about covering the holes, I don't want the cake to have a random/lopsided filling.  I don't want it to be like several filled donuts (to use your example) joined together where it's not consistent (some pieces are all filling and some are none).  Think of the filling more as a really thick sauce.


What is the best flour to use for pizza dough?

Question: I've been making pizza dough and the recipe says to use "good quality flour" but I'm not sure what it means? Are there differences in quality between different types of flour and how can I tell?
Comment: I wouldn't call this a duplicate as it is more specific (best pizza flour vs. difference between all flours)
Comment: The main issue I have with this question is that there simply is no best flour for all types of pizza. It depends on the specific type of pizza you are trying to make. For example Neapolitan pizza vs Chicago Deep Dish. It also depends on the oven you are using.
Comment: possible duplicate of [What is the difference between various types of flour?](http://cooking.stackexchange.com/questions/356/what-is-the-difference-between-various-types-of-flour)
Answer: What do we look in a pizza dough?
There are many styles of pizza: Italian Vera Pizza Napoletana, Chicago style, ... All of them have something in common in their dough: it should be stretched without tearing, and shouldn't stretch back.
Also, some recipes call for long fermentation times: 6, 9 or more hours at room temperature. With this you get a more relaxed dough (it won't stretch back), and more flavour.
Which flour characteristics give us that dough?
Millers use a tool called Alveograph to check their flour's characteristics. One of the values given by Alveographs is the p/l value. l value is an index for extensibility: how much can the dough be stretched before breaking. p value shows how hard is to give the dough a shape. p/l gives an idea on how the dough holds the shape it's been given. Flours with p/l≈1 are said to give "equilibrate" doughs for bread, as they are easy enough to give a loaf shape, and they will keep that shape once given.
Pizza flours should have a p/l≈0.5, as it means the dough can be stretched to a big disc shape, it won't tear, and won't stretch back to a smaller disc.
For long fermentation time, a high W value is desireable: W=280, 300 or 320 are common values. W is not always related to p/l values, and it can be undesrtood (informally) as "how much gluten the flour has". As gluten in a dough gets degraded with time, a lot of it is desired initially in the dough to assure there will be enough at the end of fermentation, several hours (or days, if refrigerated) later.
Forget about those 00 in Italian flours. It really only means the finesse of grounding. For pizza making I try to use strong flours with a p/l value close to 0.5, albeit I've also used strong bread flour with good results.
How can I get flours with those characteristics?
There are some specific pizza flours. Some Italian makers (with no specific order) are:

Caputo
Spadoni
You can see how W value is related to their recomended fermentation time.
5 stagioni
If you check the p/l value you'll see it's 0.6: right for pizza stretching.

If you can't get specific pizza flour, you can also try with flour specific for croissants, as they will also be strong and stretchy.
I've never eaten nor seen Chicago style pizza, so I can't help with flours specific for them, but I guess the guidelines given above should help.
Answer: The best is the Italian Tipo 00
If you can't find that flour locally, there are sellers online. I find a mix of bread flour & semolina works very well too.
This is my favourite pizza dough recipe: http://www.jamieoliver.com/recipes/pizza-recipes/pizza-dough
Comment: As I said elsewhere the "00" definition does not mean anything at all in pizza or bread making. "00" just means that the flour is white, and contains only the starch and the proteins in the wheat, and the smallest quantity of mineral residues. For pizza you need a flour high in proteins, and with enough elasticity (the values to be looked for are W around 200, and l/p around 0,5).
Comment: That's the EXACT same recipe I use and I love it!! Will definitely give the Tipo 00 a crack next time.
Answer: The answer depends upon the type of pizza you're making:
00 Flour (Caputo or San Felice are two common brands) is an italian flour that's finely milled.  It's low in protein content and performs well in high temperature ovens (e.g. coal fired, wood fired ovens).  I usually don't cook 00 under 700F.  00 Flour is almost always used in Traditional Neapolitan style pizzas.  Pizzas made with 00 have a softer texture.
High Gluten Flour is a high protein flour.  It's commonly used in New York Style pizzas.  Common brands are King Arthur Sir Lancelot, Pendleton's, Giusto's and All Trumps.  It's harder to find in supermarkets.  But you can find it in the bulk bins at some grocery stores.  Pizzas made with High Gluten Flour have a breadier texture.
Bread Flour or All Purpose Flour are commonly used flours that are higher in protein content than 00, but lower than High Gluten.  You can use these in most recipes and get great results.
Comment: Bread flour is VERY different than all-purpose.  Bread flour is, generally, a high-gluten/protein flour.  I wouldn't refer to them as interchangeable.
Comment: the italian laws about flour (and the denomination 00, 0, 1, 2, whole)  is just related to the extraction level (and not milling grade): type 00 flour is the most refined flour, meaning that it contains  less minerals and only starch and protein (minerals are only present in the bran, so the residual level of mineral, or ashes. is used to determine the "whiteness" of the flour).
Answer: 00 Flour, such as Caputo 00 is considered by many to be the best for wood-fired. There is actually an organization in Italy and a counterpart here in the US that certifies pizzerias in the making of True Naples Pizza or Verace Pizza Napoletana.
Caputo 00 is an important factor. The flour is milled in Naples by Molino Caputo (molinocaputo.it), run by a guy named Antimo Caputo. They mill a variety of 00 flours, and not all are the same. They do produce a 00 Pastry flour which has a lower protein content (9%) than all-purpose flour (11%), but their Pizzeria 00 and their Rinforzato (reinforced) 00 flours which are used to make pizza crust and bread happen to have higher protein content (12.5%) than typical all-purpose flour.
I'm getting these numbers from Wikipedia and from some data sheets that I received from Molino Caputo on the Pizzeria 00 and Rinforzato 00.
The key takeaway is that the flour number (00, 0, 1, 2) is a measure of how finely ground it is, and does not correlate directly to the protein content which is what the Wikipedia article implies with its chart.
So according to the experts, if you want to make true Naples-style pizza, Caputo tipo 00 is the best, but doesn't it come down to personal preference? Experiment and have fun, but be sure to try the Caputo flour at some point.
Answer: Using a high-gluten flour will allow more of the gas bubbles formed by your leavening agent to be trapped making an overall lighter bread that is stronger too. This is generally a desirable consistency for pizza doughs.
Answer: Well, I believe all the answers above touch on important points of the flour.  I found a local pasta/bread business that orders their flour and they are willing to sell to me at market cost.  This is a good quality source and with plenty of advice because they know their flours.
The quality of the flour needs to contain 12% protein or greater for pizza to be firm and rise and withstand high temperatures for best results.  The protein is required to form gluten that traps the gases expelled from the yeast.
Semolina Flour (Common):  good for high temperatures, sweet, high protein, provides firmness to the pizza crust. Used for helping slide the pizza into the hot oven (do not use corn meal)
Caputo Fine Milled 00 size:  For pizza is common, average protein, high temp, assures a light crust, high temperature.
General Bleached White Flour: (Use instead of Caputo) contains about 10% protein.  Is chalky and burns easily at hire temperatures.  Best to blend with other flours & cook longer between 350 to 400 degree F.
Whole Wheat (brownish):  In small quantities (1/8 total flour) provides a nice hearty flavor.  Too much Whole Wheat will be more like bread or too tart and will burn easily.
For the best quality blend fresh flour of 1 part Whole Wheat, 3 parts semolina, 8 parts Caputo or (All purpose white flour).  These provide the characteristics desired in pizza.  The flour is used in a preheated iron pizza pan 500 degree F temperature on the top shelf of the oven for 7 to 8 min.
Answer: Pizza is usually made with a higher protein flour than all purpose flour.   Semolina flour is typically used in Italy.
Comment: I've never heard of semolina flour being used for pizza dough. If anything, it might be used as something to spread on the peel or work surface to help slide the pizza into the oven. 00 flour is usually, if not always, soft white wheat.
Comment: all. In Italy, especially Naples, we do not use semolina flour to make pizza. I just wanted you to know if from a local :)
Answer: All-purpose flour is one of the best flours for pizza. It is commonly used to create thin pizza crusts. Most of the people prefer this to make New York style pizza, Neopolitan-style pizza, and deep-dish pizza crusts.
And flour type also depends on which style pizza you are going to make.
Comment: What are the characteristics of all-purpose flour (vs bread flour or cake flour) that make it best suited for thin crust pizzas? What are the different options for different styles?
Answer: Just buy bread flour. For example Gold Medal or King Arthur flour.
Comment: Thank you for contributing. However, we prefer answers with some explanations and background, not just throwing in random brands which many of the people here probably haven't even heard of (I don't know if these exist anywhere outside the US). Also, people are more likely to care for your answer if you'd at least write it as a whole sentence. I won't delete it, because it (barely) qualifies as an actual answer, but you already have downvotes, and the community is likely to react with more.


In this present time, can we go to Nirvana?

Question: I heard that when we settle our mind and focus in one thing, if we meditate we can go to Nirvana. In Buddha's time and many centuries after, people went to nirvana. So my question is, is it possible in this present time if we do all of these things: is it possible go to Nirvana?
Answer: The mind can reach Nirvana. It is unrelated to time & place. It is related to dispassion towards the world. Craving, which is an inborn instinct of all life forms, is the major obstacle to Nirvana.
Answer: Yes
One of the qualities of the teaching is "Akalika" which means "Timeless". Lord Buddha directly said that the teaching is fruitful regardless of the time it is practiced in. So there is nothing stopping you or anyone from realizing the teaching.
Nirvana is not a place like "Heaven" mentioned in other religions. It is a state of mind. As long as true words of lord Buddha exists,the path is open.
As a beginner to the path do not worry about the end you are trying to reach. Keep practicing so that one day you would reach the destination.
Here are few links for you to expand your knowledge...
http://zugangzureinsicht.org/html/index_en.html
www.mahamevnawa.lk/inenglish
www.Dhammasiith.blogspot.com
Answer: This Dhamma is not sterile. The Dhamma is alive. The Dhamma has the quality of "Akalika" (not belonging to time). So for those who walk this Noble Eightfold Path in an orderly manner, it is still possible to attain Nirvana.
Having said that I have to now say that it is much harder for a person to realise Nirvana (Nibbana) in the present day. It is because the protective fence that was there in the first 1000 years is not there anymore. Today the world is influenced to a greater degree by Asura Forces.
In Samyutta Nikáya Sutta 16.13, the Supreme Buddha warned that the true Dhamma would remain unadulterated for 500 years after his passing into Nibbána. It is not so today. Today, the Supreme Buddha's teachings are referred to as Tipitaka (The Three Baskets of Treasuries), although they were called "Dhamma-Vinaya" by the Supreme Buddha in the discourses. In Anguttara Nikáya Sutta 4.180, the Buddha  refers to Dhamma as the Suttas (discourses). Vinaya is the disciplinary code of monks and nuns. In the Nikáyas, it is also implied that the Suttas are "Saddhamma" which means "true Dhamma".  (to be continued....)
I mentioned that the Suttas are "Saddhamma" which means "true Dhamma" - not my words but that of the Supreme Buddha. I left it at that for a couple of days expecting a reprisal. Today one has to be 'politically correct' in what one say and do in public. The present-day attitudes are very much a product of the rapid development of science and technology. What the Buddha has said is patisotagami or against the current of conventional thinking. Buddha knew this well. That is why He said,

"Dear Bhikkhus, ones who would not realize this Dhamma is like this earth (in amount). Ones who realize this is like this small amount of soil on my finger nail."

Only if we develop two important attitudes that strengthen skillful desires: a sense of dismay (samvega) over the universality of suffering that we tend to see as otherwise, and an attitude of heedfulness (appamada) to avoid being duped by types of desires that come our way, that we will have a sense of urgency towards the practice of Dhamma, then 'Nirvana' is not that far.
Many a times Buddha had said things to induce samvega:

"Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries—enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released." — SN 15:14-19

According to the Buddha's preaching, amount of people who would NOT attain enlightenment is like the amount of soil in this earth. Amount of people who would attain the enlightenment will be like the small amount of soil one can put on a finger nail.
Answer:
I heard that when we settle our mind and focus in one thing, if we
  meditate we can go to Nirvana.

Its much more deeper than this. To put some context to this you can settle your mind in many ways by calming your mind doing breathing exercises, listening to music or many other forms of meditation. This is not what budha's way of calming your mind to go to nirwana. Only way of meditation mentioned in budhism is Anna Pana Sathi (Assa Passa Bawana) Meditation
What it means is  focusing on your current thoughts. If good thoughts come to your mind keep them and refrain from bringing in bad thoughts inside. Also create good thoughts in your mind and remove existing bad habits from inside. This is Anna Pana (Anna pana is not a breathing exercise nor focusing on breathing)

In Buddha's time and many centuries after, people went to nirvana. So
  my question is, is it possible in this present time if we do all of
  these things: is it possible go to Nirvana?

When you do Anna pana sathi you have to do it in the present moment. For example if a bad thought (Moha, Raga, Dewesha) come to your mind few mins earlier you can't clean that using Anna Pana meditation. You can only clean current thoughts not past ones. So that's why budha said Nirwana is at the current moment.
Person who do Anna Pana meditation are capable of Removing Raga Attachments, Moha Attachments, Dwesha Attachments at current moment. You can remove all three with practice of Anna Pana meditation. Any of these could come at any order in a given moment.
Raga - getting attached to something because you like it
Dwesha - getting angry or hate something because you don't like it
Moha - Because you don't know of the truth you measure things between good or bad
Ex: You go to a restaurant and eat a peace of cake which is the best cake you had ever tried. at that (Current) moment you get Raga thoughts and mind get attached to this thinking this is the best. This thought gets stored in your mind how awesome is this cake.
after few months later your mind provide the picture of the cake and all those thoughts stored in your mind suddenly comes to you. again you get attached to that thought in current moment thinking about how awesome was that cake. You picture it taste it from mind.
Next day you go to the same restaurant and order the same cake. But you realize its not the same taste. You get bit of anger at that moment (this is Dwesha) thinking why is it bad today
Then on the very next moment with moha mind you compare the old cake with new cake thinking how awesome was that and how bad is this. It is the same cake same cook same restraunt  but different taste but you got attached Raga Dwesha Moha mind.
For a person who had become enlighten minds at those moments are different
He eats the cake at the current moment notice it is a tasty cake and that's it. He doesn't get attached to it (he doesn't fantasize about the cake with Raga) therefore for him story ended at that moment and moments to come.


Photoshop CS4 - what does a small circled 'x' mean next to a cursor?

Question: In a new layer in a CS4 Photoshop document (Mac), my shape tool cursor has a small circle with an 'x' in it - to the bottom-right of the crosshair. What does this mean? If I try to draw a rectangle, the outline is created but it is not filled with the current foreground colour. Anyone know what might be causing this? I tried taking a screenshot but the screenshot utility doesn't capture the active cursor.
Answer: Does your cursor look like this?
If so, it means your shape tool is set to "Intersect path areas".
Answer: D'oh - I had 'paths' selected instead of 'fill pixels' in the tools options (Icons in top-left of screen on my version). Looks like the icon is there to remind you of this - except I had forgotten what it meant. Its been a while since I used P'shop...
Comment: I posted my on solution 7 minutes before him.
Comment: so now whats your plan?? i think faraay lead you to this....


computation in exact sequence of abelian groups

Question: Suppose we have this exact sequence of abelian groups
$$G_1\xrightarrow{f} G_2\xrightarrow{g}G_3\xrightarrow{h}G_4\xrightarrow{k}G_5.$$
I need to compute $G_3$ and I only know the expression of $f$ and $k$ which are both injective
 group homomorphisms. Can I say that $G_3={G_2\over \mathrm{Im}(f)}$, and so it remains to compute only $\mathrm{Im}(f)$?
My guess is yes. Since $k$ is injective then $\mathrm{Im}(h)=\ker(k)=0$ hence $h$ is the zero homomorphism sending each $g\in G_3$ to $0$ hence $\ker(h)=G_3=\mathrm{Im}(g)$. Now ${G_2\over \ker(g)}\cong \mathrm{Im}(g)=G_3$ hence $G_3\cong {G_2\over \mathrm{Im}(f)}$. Is my reasoning correct? Is there any other simpler way to do this?
Answer: Correct. I would do the same..


Why would Q attach the computer of a known cyberterrorist to the MI6 computer network?

Question: In the movie Skyfall Shouldn't Q like connect Silva's computer to a secure line or something, considering that he was a known cyberterrorist? Isn't there any sort of internal protocols for the networking system?
Comment: It seemed in the film that even Q realized he'd blundered by doing this.
Comment: Bcoz this Q was young, enthusiastic and naive. With inexperience comes a false sense of grandiosity!
Answer: There is no proper reason whatsoever for him to link the unsecure device retrieved from an enemy to the network of MI6. The usual approach would be to treat it with the highest level of suspicion and analyze the hardware and contained data in a secure isolated environment, and Q should have known that, considering that he is supposed to be a genius IT specialist.
This is a trope called the Idiot Ball (warning: TvTropes link!):

A moment where a character's stupidity fuels an episode, or a small plot line.

If you are looking for a reasonable in-world explanation, one could come up with the following reasons for his mistake:

They had Silva captured and detained. They did not knew that this was part of his plan, so they may have had a false sense of security.
There was highly encrypted data on the device which he could probably decrypt faster by using the networks ressources.
Q is young and very sure of himself. He probably thought that the security measures he set in place were enough to protect the network from any kind of attack.

Still, that was a very stupid thing to do and for me was one of the biggest facepalm moments in the movie.
Comment: "one of the biggest facepalm moments in the movie" and that is against some pretty stiff competition!
Answer: While I don't remember that specific scene (not sure I've even seen the movie), this sounds once again quite like something the writers made up just for the story. As such it's rather hard to answer why Q would do it (because it's the same reason: just for the plot).
Unless you've got some really nasty bug in your operating system or some insecure autorun policies set, there shouldn't happen anything once you connect a drive (and you don't try to execute something on it). Everything on it is just inactive/passive data.
There could be additional safeguards built into the hardware (similar to drive encryption), but once again that's unlikely to cause any side-effects outside; at least nothing software only (other than potentially reading wrong information).
If he intended to execute something on the drive, then yes, you're right, it's very careless.
Although, to be honest, I'd try to create a copy of the drive (so it's unable to destroy the data on it itself) and then mount that in a virtual machine (so it won't be able to destroy my soft-/hardware). It's not just about disconnecting from the network (you'd most likely do it on isolated hardware to begin with; so you wouldn't have to worry about disconnecting first).
Comment: There exists something called "autorun" which is a simple (ini) file that links to an executable to be called when the device is plugged in, just like with install cd's. Still it is really stupid to have this feature not disabled (which is a simple thing to do) and plugin a device. Downloading a Trojan/virus just to "read it" can still get you effected, have a look at Macro virusses, though I guess something as simple as notepad is quite secure.
Comment: Not only is there autorun,  but drivers may be malicious, drives can interface on a hardware level with other hardware in the system by directly accessing the bus, file inclusion vulnerabilities, various ways of executing malware, 9day vulnerabilities,  and many other ways of exploiting a system. Attaching malicious hardware is an insane or completely uninformed act.
Comment: 0day, not 9day... stupid phone keyboard :-)
Comment: Well, he certainly *did* execute something or view some files on the hard drive, since he and *James* were actively trying to decrypt this stylish underground-network-plan-code. So it wasn't that he just plugged it in and everything started to burn. But I agree that this wasn't particularly intelligent or reasonable an action.
Comment: Yep, but even then it's questionable what's used to view that data. You can download a virus or trojan, open it with Notepad, etc. this won't get you infected.
Comment: Well, sure, but I guess we can assume that magic stylish interface was certainly something close to "excuting".
Comment: Because it was made for the bulk of James Bond fans to believe not technology buffs, and for story flow. Occams razor. Maybe not the best answer but the possibly the simplest.
Comment: @invalid_id Correct, although it's disabled by default for most disk types starting either Windows Vista or Windows 7 (don't remember). Other platforms such as Unix derivates will ask the user as well. Macro viruses still require the actual file to be interpreted/executed. You're not infected just by having it sit on your computer.


How does the nitrogen generation system in a Boeing 777 work?

Question: How does the nitrogen generation system in a B777 work and how does it differ from that used in a B787? Any diagrams will be appreciated.
Answer: The 777 system
As RAC points out, "nitrogen-generation system" is somewhat of a misnomer. All the system does is remove oxygen from the ambient air and blow the rest into the center fuel tank; there is no chemically "new" nitrogen created. The 777 architecture is basically the same as the schematic that mike provides; in fact, all bleed-air aircraft use pretty much the same system. For example, here is an Airbus schematic:

Parker has a breakdown of the major components. Summarizing it and filling in some gaps, we have:

Ozone (O3) converter: Basically a catalytic converter that converts triatomic oxygen (ozone) to biatomic ("regular") oxygen to protect other elements in the system from oxidation.
Heat exchanger: Cools the bleed air (which is really hot when it comes off the engine), again to protect other elements of the system and increase their effectiveness.
Air separation module: Physically removes almost everything but the dinitrogen (N2) in the air. This separation is accomplished by running the air through semipermeable fibrous tubes; because almost all the non-N2 molecules present are smaller than the N2 molecules, those smaller molecules pass through the membranes and are exhausted overboard, leaving only the nitrogen to exit into the fuel tank.
Other: There are various filters to protect components from particulate matter, valves to control the timing and rate of flows, controllers to control the valves, and sensors to inform the controllers.

The 787 system
The 787 is a no-bleed airplane, which means that instead there is an electric-driven compressor to supply the NGS rather than bleed air. This setup requires a slightly different heat-exchanging architecture, but the overall function and operation of the primary system components are similar.
Answer: The NGS uses proprietary tech to separate nitrogen enriched air from bleed air. Diagram attached.
Comment: ...and why are Boeing allowed to keep technology that would greatly increase aviation safety secret?
Answer: On the 787 it's NOT a nitrogen generation system, it's an oxygen depletion system. If the air starts at 77% N2 and 21% O2, and you take half the oxygen out, you end up with 87% N2 and 11% O2. The whole idea is to reduce the balance of fuel fumes v oxygen above the fuel, so that it won't burn.
On the 787, air from the Cargo Heat system is passed through a catalytic convertor (like your car), which takes out some of the oxygen. The reduced-oxygen/enriched-nitrogen is then fed to the fuel tanks like a vent system.


Where can I learn about the History of Photography?

Question: I am taking a semester long independent study class on photography, and one of my goals is to learn a brief history of photography; are there any great resources that, without going into too much detail, outline this from the 1800s till recent times?
Answer: Jeff Curto of the College of DuPage releases podcasts recorded from the History of Photography course that he teaches. While a whole semester's worth of lectures would not count as "brief," a couple of early lectures each semester consist of an overview of the history of photography, and may be sufficient. Subsequent lectures address particular topics in greater detail.

Photo History – Class 2 Spring 2012 – History Survey Part 1
Photo History – Class 3 Spring 2012 – History Survey Part 2
Answer: The BBC had a documentary The Genius of Photography.  I believe you can find extended segments of it (or the whole thing) on youtube or on the BBC site.
There is also a book based on the series
Answer: As with almost any question asking for an introductory history of something, Wikipedia is a great place to start. There's a whole article on the History of Photography. However, this focuses very heavily on the technical side of things, and is in some ways as if the article on history of music were solely this section.
Still, I think a good encyclopedia article is    wanted here — a comprehensive overview that can be quickly read and which sticks to the highlights rather than digging into details. So, I'm going to point instead to Britannica's article on the History of Photography, which covers technological advances but also the artistic and social development of the medium, including many references to important and influential photographers. It's really very good. The bibliography of the article should provide some good further reading as well.
Answer: Apart from the fact that it stops at just about the point that digital photography makes its entrance, the book On the Art of Fixing a Shadow: One Hundred and Fifty Years of Photography is a superb and copiously-illustrated reference (with excellent printing). It appears to be out of print now, but is still available online (for less than I remember paying for it around 1990), and should be available in good libraries. If you do decide to buy it, it's a beautiful book that is worth having for more than just a historian's interest.
Comment: Dear Stan (@stan), does this book have a history of technical details, such as evolution of camera mechanisms, lens design etc?
Answer: About the initial, pioneeristic period, I have read and recommend a short monograph (about 120 pages) by Beaumont Newhall, Latent Image. Given the time he is describing, the focus is on the researches and the debates of these great people (Niepce, Talbot, Herschel, Daguerre and so on), with a focus on the historical (lifes of the people involved, interactions among them) and scientifical aspect.
Reproduction of the first images are contained within the book, including some early daguerrotypes, Talbot's first negative and so on).
The author, Newhall, has written a History of Photography from 1839 to present which, unfortunately, I have not read yet. From what I've read, I can imagine that it is a must-read book.
As an aside, the monograph contains a reference to "Talbot, William Henry Fox, The Pencil of Nature, London, 1844-1846" which is the first book illustrated by photographs. Apparently this book is available in modern printings.


Congratulating someone on the new Era/Emperor

Question: As Japan moves into the Reiwa (令和) era, I was wondering if any traditional greetings exist to congratulate someone on the new Era, Emperor or Year of the Japanese calendar?
Comment: Possible duplicate of [How would you express the sentiment of "Happy New Era"](https://japanese.stackexchange.com/questions/66415/how-would-you-express-the-sentiment-of-happy-new-era)
Answer: No, there's no such greeting. In the last 150 years or so, a new era has been associated with the previous Emperor's demise, so it's not a happy event in the first place. This time is an exception, and people may be allowed to say something including おめでとうございます, but there is no fixed, traditional way of saying congratulations.
(Disclaimer: I'm writing this from the standpoint of an ordinary native speaker. Experts may know some rare phrase that was used long ago.)
Comment: That makes sense. Thank you for answering so quickly and I hope that I didn't offend by phrasing the question in the way I did. It should have come to me that the current emperor was the first one to abdicate in a long time, making it a more cheerful exception. Thanks again.
Answer: the facebook group for Tsubaki America Grand Shrine is using "Reiwa Gengo Banzai". I hope this is helpful.


How would I use a filter to remove header banner on certain post types

Question: I am using a child theme of twenty-twelve, and want to remove the huge banner image in the header for certain post types. How can I use add_filter() or add_action() to do this? I don't want to mess with the header.php file in the parent theme, I just want to preg_replace the HTML content that the header has. Excuse my ignorance, but I am fairly not versed in WP yet.
Answer: Copy header.php to your child theme so you're not editing the parent theme's file.  And on line 49, you will see this line of code:
if ( ! empty( $header_image ) ) : ?>

This says if header image is not empty show the header image.  So you can add to that condition to check for any post type you want. Like this example:
if ( ! empty( $header_image ) && get_post_type() !== 'my-posttype' ) : ?>


What is the difference between Tor and Tails

Question: This is kind of a noob question but I would appreciate some response nevertheless. I have been reading a lot about Tor and Tails recently but I am still confused on what does what and the difference between both of them, so I would like to know what the difference is between TOR and TAILS.
Answer: To put it in simple terms, Tor (or The Onion Router) is free software that enables anonymous communication on the internet. Tor helps you protect your online privacy and helps you defend against network surveillance and traffic analysis. it prevents somebody watching your Internet connection from learning what sites you visit, and it prevents the sites you visit from learning your physical location. Tor achieves this by directing Internet traffic through free, worldwide, distributed servers which are run by volunteers.
Tails on the other hand is a full-blown Debian-based operating system that comes with several built-in applications pre-configured with security in mind: web browser, instant messaging client, email client, office suite, image and sound editor, etc. It is designed to be used from a DVD, USB stick, or SD card independently of the computer's original operating system, and it leaves no trace on the computer you are using unless you ask it explicitly. Have a look here to know the full list of features and included software. Tails relies on the Tor anonymity network to protect your privacy online:

all software is configured to connect to the Internet through Tor
if an application tries to connect to the Internet directly, the connection is automatically blocked for security.

If you have read this much, there are few things you can do now:

Please consider running a relay to help the Tor network grow.
Tell your friends! Get them to run relays. Get them to run hidden services. Get them to tell their friends.
If you like Tor's goals, please take a moment to donate to support further Tor development.
Answer: Tor (not TOR) is like your router at home. To get to the internet, you connect to your router. Tails is an operating system, like Windows. The interaction between Tor and Tails is that Tails is configured to use Tor by default.


Help. 4 year old won't potty

Question: OK.  He's 4. He's had speech issues so communication with  me is tough and he still isn't telling me he needs to go.  I've been asking him and making him go pee about every hour.  When it comes to pooping he always tells me no. Then I catch him hiding bent over holding his butt. I have been trying and trying and he just continues to hide.  I've tried rewarding him and praising him and he still refuses.  Once I catch him and run him to the toilet he won't even try to poop. He just sits there. I don't want to just let him go back to diapers. . I don't see how backtracking would help the situation.  I just don't know what to do anymore.  I'm so frustrated and I don't want to lose my temper.  It's just got me wanting to pull my hair out.  Help!
Comment: So to clarify, he is trying to hold it in rather than pooping on the toilet?
Answer: Both my kids were 4 1/2 for stool continence. Most important: Don't panic.
Switch to pull-ups if you haven't already done so. After 6 months in pull-ups, one day, my son got up, put underpants on himself, and has had only 2 accidents since. Not a word from his mom and me beyond what you've done.
My daughter was more sinister. She was allowed to pick out a stuffed animal from Dollar Tree for every successful use of the toilet. It worked; although eventually we had to work our way up to Ty animals ... That went on for a few montha, and now we have about 200 stuffed animals. But who doesn't like making a pile of stuffed animals to jump in?
The book Everyone Poops or any of the more modern equivalents might be a good bedtime read. It is imperative you don't get angry around stool issues. He doesn't like disappointing you either. He doesn't get it yet, and frustration can make it worse. But he will get it, you have to believe.
Answer: In my experience, defecating in a toilet takes longer to train than urination. I would simply take your child every 60-90 minutes and sit until there is a result. I am betting that you know when/ times of day that this is most likely to happen. Do not get mad at a soiled diaper*, but do praise using the toilet. Read, watch a movie, play a game, make potty sitting as pleasant as possible. *Diapers and pull-ups are made for this. Holding waste is not healthy. I do not like food rewards or things that cost money -- but you could promise a trip to the park, a push on the swing/a favourite game if your son defecates in the toilet.

Help. 4 year old won't potty


How to find coefficient of $f(z)$, if $f(z)$ is differentiable.

Question: Let $z=x+iy$, $x$ and $y$ are real numbers. $f(z)=6x-4y+i(ax+by)$, $a$ and $b$ are real numbers. If $f(z)$ is differentiable, find $a$ and $b$.
Comment: Are you familiar with the [Cauchy Riemann Equations](http://en.wikipedia.org/wiki/Cauchy%E2%80%93Riemann_equations)?
Comment: You need to check if $f(z+h)-f(z)=w\cdot h+o(h)$. Calculate and simplify the left hand side with $z=x+iy$ and $h=u+iv$.
Answer: If $f$ is differentiable as a complex function, it must fulfill $$
\begin{eqnarray*}
  \frac{\partial \Re(f(x+iy))}{\partial x} &=& \frac{\partial \Im(f(x+iy))}{\partial y} \\
  \frac{\partial \Re(f(x+iy))}{\partial y} &=& -\frac{\partial \Im(f(x+iy))}{\partial x}
\end{eqnarray*}
$$
where $\Re(z)$ denotes the real part and $\Im(z)$ the imaginary part of a $z \in \mathbb{C}$. Those equations are called the Cauchy-Riemann differential equations.
If you compute these derivatives, you should be able to determine which values $a$ and $b$ must take to have your $f$ fulfill these equations.
Answer: If a complex fuction $f(z)=u(z)+iv(z)$ is differentiable, it's real and imaginary parts should satisfy Cauchy-Riemann condition: $$\frac{\partial u}{\partial x}=\frac{\partial v}{\partial y}$$ and  $$\frac{\partial u}{\partial y}=-\frac{\partial v}{\partial x}$$
so in your case $\frac{\partial u}{\partial x} = 6$,$\frac{\partial v}{\partial y} = b$,
$\frac{\partial u}{\partial y} = -4$ ,$-\frac{\partial v}{\partial x} = a$. It gives:
$$a =4,b=6$$


Percentage fermentable ABV calc' Factor,

Question: Is .163178144 (.1632)  the factor for deciding the ABV %  from the percentage fermentability of any fermentable beer solid, in 5 gallons  ?
cheers. DD.
Comment: Please add more information to this question, formula you are using and your units that you are using (e.g. plato/brix etc)
Comment: Ok, for want of answering my own question, I was really looking for confirmation of that number or one like it.  So my example would be a malt extract that is 64% fermentable ,is made up to a 1040 wort, so .64 x 40 points = 25.6 points, now x by .163178144,will give 4.177 % v/v.   now divide this by .131 (you know what this factor is), and you end up with the gravity drop of 31.8844, take this from the OG and you have the FG 1008.1145, which works out at just over 20%,- a one fifth gravity beer. Sorry if you didnt understand my question,Yes it was a little brief. Close issue.
Answer: The relationship is not linear so multiplying by 0.13 or 0.131 works for the majority of 4-7 percent beers roughly, but you need to factoring in the gravity drop and weigh this against the effect of the alcohol on your gravity.
ABV = (OG - FG) * factor
Here is a table of the factors to use:
<code>(OG - FG)   % ABV        Factor

Up to 6.9    Up to 0.8   0.125
7.0 - 10.4   0.8-1.3     0.126
10.5 - 17.2  1.3-2.1     0.127
17.3 - 26.1  2.2-3.3     0.128
26.2 - 36.0  3.3-4.6     0.129
36.1 - 46.5  4.6-6.0     0.13
46.6 - 57.1  6.0-7.5     0.131
57.2 - 67.9  7.5-9.0     0.132
68.0 - 78.8  9.0-10.5    0.133
78.9 - 89.7  10.5-12.0   0.134
89.8 -100.7  12.0-13.6   0.135
</code>
Comment: Best answer of all, brilliant, I think that it must be to do with the  alcohol 'curve' on graph. I did hear about this a few decades ago but thought it a myth.Now i am straight with this,- variable factors, after 46 years of ignorance, thank you.!
Answer: What are you u doing to get your readings,I use a hydromete.
For me it is the easiest.I recommend.Go the Brewers friend website,it has a ABV calculator.
Comment: Yes, Jack I know about 131,  Its the percentage fermentability side that I am looking at. See note to Martin, Cheers.
Answer: No, not to my understanding. I believe the hydrometer often used is a saccharometer. It's calibrated to measure sugar content and it's effect in boyency. As far as total dissolved solids (TDS) go it's generally assumed these are fermentable sugars in wort. But this because increasingly untrue for darker beers. In my experience large amounts of dark and heavily roasted malts will produce more TDS that cannot be fermented.
I believe the common equation is:
ABV = OG - FG * 131
Were OG and FG is original gravity and final gravity respectively.
Best of luck!
Comment: Hi Martin thanks for that, I know about the x .131, but on the saccharometer it has the potential alcohol of 16 ozs sucrose in 1 gallon H2O, Marked at just less than 6%, say 5.95%, so if sugar is 36.5 points per lb/gall then multiply by .1632, in order to reach the 5.95, as sugar is regarded as 100% fermentable. So, which of these three figures is correct?    Cheers, Just trying to dot the i, and cross the t.
Comment: I don't follow, but here goes what I know, maybe it can help. Most formulas use weight calculate expected ABV. This is used when priming bottles for instance. Also, sucrose, dextrose, dry malt extracts all have different alcohol yields in terms of a weight unit (g or oz). In beer I believe maltose is the common wort sugar. The 131 constant is merely an approximation. I've seen anything in the range from 129 to 131 used. But for more accurate yield numbers there are other formulas. But in the range 1-7 % ABV its supposed to be accurate enough. Best of luck!
Comment: Thanks for that Martin, moving away from the saccharometer then, If you had a wort of 1040, with a known percentage fermentable maltose content say 64%, then 25.6 points of that 40 are going to ferment (the resultant aim will be a one fifth gravity beer, so we are looking at circa 4.1 % ABV, I have used a factor of .1632 to get the same result as using .1293, on the gravity drop method but is .1632 a relevant factor?
Comment: Many thanks for your efforts Martin, but I have just found a question of it from 5 years ago from 'daveb' with an absolutely brill answer from Mdma . Take a look. All the best.
Answer: I use plato, and the formula for that is (OG-FG)/(2.0665-0.010665*OG). You can find that in Fix
Comment: Multiply the gravity drop by .13 is best and easiest, if you know your 13 times table,even easier.  Cheers.
Comment: Not in Plato, I'm led to believe. Or at least, not if you want an accurate result.
Comment: i dont use plato


eosio.contracts and how it works

Question: Hello guys I have a question about eosio.contrcats I am confused about when I want to deploy my contract and my contract use an esoio.contracts should I deploy them too or there is an eosio.contracts that everyone using it?
Answer: eosio.contracts are representatively three. (eosio.token, eosio.msig, eosio.system contracts.)

eosio.token is able to transfer your token or EOS coin
eosio.msig give a multisig
eosio.system is able to vote some BP or create new account...(you can
alos see cleos system command)

So These are very basic contracts when you using EOSIO blockchain.
if using your private blockchain, you have to deploy eosio.contrats. But you Already use main-net. You don't.
Comment: i still lost about something that if i want to make  my own token i have to deploy my token contract or i just make a whitepaper and block.one will  add it so all users can use it?
Comment: @AhmadKajjan I guess you followed the tutorial page. If you want to make your own token, you would make your own token contract and deploy your blockchain(private or public). Only you can use it. (But if you add some options. anyone can use it)

eosio.contracts and how it works


Getting more screen resolution options for an IBM X31 with an external monitor

Question: I have an IBM X31 running Windows 7. I recently tried to connect to it to a 17" LCD monitor, but the screen looked odd. When I looked at the settings, it seemed to be set at a rather odd resolution, and I couldn't set it to the native resolution, 1280 by 1024. How might I be able to gain more screen resolution options?
Comment: Have you checked Windows Update for additional drivers?
Answer: I would first check that the driver for that particular monitor is installed, and that the monitor is properly recognized, if the external monitor comes up as 'generic 17" monitor' that tells you the system is making certain assumptions.  Usually you can find / select the proper monitor.
Thats probably the best route to troubleshoot.  Otherwise update your video card drivers to the latest.
Answer: As I understand, your laptop normally works well on its own, but gets into trouble when connected to the monitor?
First, I'd try to download the relevant video drivers from here. I don't expect Windows 7 to have drivers for a laptop that old. Don't use the installer to install the drivers, however; unzip the drivers (for one or all of the OS-optimized drivers), and go to Device Manager and try to update the driver whilst pointing Windows to the destination of your unzipped drivers.
Try this and report back.
Comment: it says that the drivers are fully up to date


Lyapunov Exponent of a Trigonometric Solution

Question: I am attempting to work through the following problem. I have no problem with part (a) and have included it only for context.
(a) Verify that $u_n = \sin^2(2^n)$ is a solution of the map $u_{n+1}=4u_n(1-u_n)$.
(b) Calculate the Lyapunov exponent (LE) of that solution.
I have the beginnings of a working of part (b) but I can't find any trig examples of calculating the LE in any notes. What I have so far is:
$L = \lim_{N\to\infty} \frac{1}{N} \sum\limits_{n=1}^N \ln|4\cos(2^{n+1})| \\
= \lim_{N\to\infty} \frac{1}{N} \left[ 2N\ln(2) + \ln|\cos(2^2)\cos(2^3)\dots \cos(2^{N+1})| \right] $
I could argue, due to $\cos$ being bounded, that $L \leq 2\ln(2)+1$ but that doesn't tell me if $L$ is negative or not. Maybe I'm overcomplicating. Any help would be very much appreciated.
Answer: The following identity can be established by induction and/or the identity $\sin(2x)=2\sin(x)\cos(x)$:
$$\prod_{j=0}^{k-1}\cos(2^jx)=\frac{\sin(2^kx)}{2^k\sin(x)}.$$
Can you take it from here?


Rake or leave lawn clippings?

Question: Is it better (healthier) for the lawn if rake and dispose of lawn clippings or if you leave them on the lawn to decompose and return to the soil?
Answer: As with most horticultural type questions, there's no simple yes or no answer to this. If you leave the cuttings, then nutrients are returned to the soil, drought resistance is improved, moss is inhibited and you are saved the task of taking the clippings away.
But there are disadvantages - if the turf is weedy, then you're likely to increase the number of weeds by leaving the clippings. In damp weather or damp regions, the turf becomes spongy and susceptible to disease, and aeration is impeded. Also, if the cuttings are very long, they form a layer over the whole lawn, which not only looks awful, but takes longer to break down.
In the UK, which is obviously pretty damp most of the time, the general advice is to let the clippings fly when the weather is hot and dry, but to collect them the rest of the time.
Comment: I should have added that this is in Arizona - didn't realize that would make a difference...
Answer: I always recommend leaving the clippings on the lawn and I've had good luck with it myself. As Bamboo says, there are disadvantages to this. I would add that a good set of mulching blades is a good idea if doing this as smaller bits will decompose more quickly. Also, don't let the grass get too tall between cuttings or over-fertilize as this could lead to thatch problems. Fertilizing promotes quick growth, which means more cutting, which means you may end up adding clippings to the lawn much faster than they can decompose, leading to a buildup. That buildup is thatch. When this problem is detected however, you could bag for a few cuts to let the process catch up.
Answer: Bamboo is right, there's no cut and dry answer - although cut and dry is a good summary of my answer.
Cut it, collect it, compost it and then return it to the lawn. You'll need to compost it with other fine materials (ie not whole corn cobs). I have a nice little pile in a corner of my yard that's part leaves and part cut grass (mowed leaves, it's easier than racking). It's composting nicely and I intend to recycle it into my lawn to fill in some low points.
On the plus side:

Avoid thatching
Avoid unsightly grass piles on my pretty lawn
Any weeds can easily be removed from my compost pile.

The down side is:

It's more work to collect that leave it on the lawn.
You need a bit of room for your compost
It can take a while to break down

There's plenty on this site about making a rich compost and they almost always include lawn clippings. Throwing them away would be a waste!

Rake or leave lawn clippings?


Does the phrase "but although" work together?

Question: I have the sentence: "But although you hate me now, I believe that you will forgive me over time." I'm not sure if the phrase makes sense because the words are essentially the same word. Any help?
Comment: The two words are unrelated. *But* apparently continues the thought process from before (a previous sentence, maybe), while *although* connects the upcoming two clauses: "you hate me now" and "I believe ... ".  Please provide the broader context.
Comment: I'm not sure why anything else was written after Kris's accurate and complete response.
Comment: If you like, "But" emphasises "although"…
Comment: *although you hate me now* is a parenthetical insertion, and should be set off by commata on both sides.  This makes it clearer that the payload of *But* begins with *I believe*.
Comment: You're missing a comma.
Answer: The proper punctuation is "But, although you hate me now, I believe that you will forgive me over time." (With a comma after "But".)  The phrase "although you hate me now" is a "parenthetical" (an expression which can be omitted without changing the syntax), and it should be set off by commas in normal usage.
Answer: The sentence is OK.  The words but and although are not the same, since if they were the same, either word could be left out and the sentence would still make sense, and have the same meaning:

Omit but and the sentence is still correct and has the almost same
meaning:

"Although you hate me now, I believe that you will forgive me over
  time."

Omit although, and there appears to be a word missing or a
punctuation or syntax problem:

"But you hate me now, I believe that you will forgive me over time."

And yet notice how the meaning can be preserved by moving the leading
conjunction to the middle:

"You hate me now, but I believe that you will forgive me over time."
Comment: So would it also be okay to say: So although you hate me now, I believe that you will forgive me over time. Right?
Comment: Yes, that would also be OK.
Answer: Tautology
This is a tautology. The definition of tautology according to OLD:

The saying of the same thing twice over in different words, generally considered to be a fault of style (e.g. they arrived one after the other in succession).

BBC Academy has a guide called "BBC News style guide", which includes a page on grammar, spelling and punctuation, it says, among other things, the following (this is a direct quote from their page):

Tautologies
Try to avoid them. Common examples include:
advance warning, armed gunmen, universal panacea, She has given birth to a baby boy, mutual co-operation, fixed phone line, local resident, crew members, past history, exact replica, anti-government rebel forces, pre-conditions, pre-planned, Sharia law (Sharia means Islamic religious law), weather conditions

Double contrast
In the cases illustrated above, it is quite clear what one means, for example "armed gunmen" are clearly people who are armed (the added armed does not call into question the meaning of the word gunmen).
In your case this is different, both but and although indicate contrast, so the but serves no purpose in "But although". Therefore, one could just write:

"Although you hate me now, I believe that you will forgive me over time."

When "but although" can be correct
The above does not mean the combination "but although" is always wrong, they can be used in a way where both contrast on different aspects. I do not have a proper example, but I can refer to this answer on ELL, which argues (also without an example of the two words being used next to each other) both words can be used in a contrastive conjuncture.
Comment: I can't guarantee that the greater context makes sense, of course. I'm just saying the quote *doesn't* make sense except in the context of a preceding sentence, extant or implied. The *but* doesn't serve the same purpose as the *although* there.
Comment: On a plain reading of the OP's quote, the sentence wouldn't stand alone - there is an implied statement from which the OP's sentence draws a contrast. The function of *but* isn't related to that of *although*.
Comment: @Lawrence are you sure about the existence of a preceding sentence? It could be that the sentence is used after an action, e.g. calling the cops on your child, then saying the quote. The OP would know their child is angry through body language, an angry facial expression, perhaps even a middle finger pointed at them.


Creating a map in SharePoint

Question: I would like to create a map of a small area with about 1000 buildings.  I am looking for a way to be able to highlight specific sections and then specific buildings within that section.  When you highlight that specific building it will give you information regarding that building.  I figure I need to create a SQL database that has all the information for each building and then link each SQL ID to the corect building.  I would also like to be able to search based on the information held in the database.  Does anyone know the best way to achieve this?
Answer: On codeplex you will find a smart map integration for SharePoint under the following URL http://smil.codeplex.com/.
For the geodata that you want to overlay on your map a simple Rss enabled SharePoint list could be used.
Answer: I think you can use gmap to build
Comment: While this post may answer the question, we prefer more details such as "why". Please edit your post with additional details. See [answer](http://sharepoint.stackexchange.com/questions/how-to-answer) for general guidelines.
Answer: Kevin,
Based on the requirements you have mentioned, it looks like you have more to deal with a custom application (Visual Webparts + Custom Database) based solution than using SharePoint. SharePoint over here can host the aspx pages holding your application and nothing more. It will give you the publishing infrastructure for easier management.
If you wish to design the complete solution using SharePoint, you need to identify the possible corners of SharePoint Object Model and how they can fit into your requirement. Like for instance you can use the list driven infrastructure to store information of the buildings and use CAML + c# in your webpart to show building details on highlight. For search you can use allow items in the list to be crawled by the SharePoint search and leverage Search based classes provided by SharePoint on your search webparts.
It all depends on how you can leverage SharePoint to address your application's requirement more efficiently than writing every classes and namespaces from scratch.
Answer: OpenMaps, YahooMaps, Google Maps, Bing Maps, all offer API's to accomplish this.  You could link the data from a SharePoint list, and that would be easy enough for SharePoint to index.
Here is good overview of a similar project on Slide Share:
http://www.slideshare.net/lightningwhelk/google-mapsunccause.

Creating a map in SharePoint


What books and videos would you recommend to an absolute beginner of Chess?

Question: The entirety of my current chess knowledge consists solely of the valid moves which the pieces can make. I've played a few matches, but my moves tend to be aimless, by this I mean they lack any purpose. What books and video series would you recommend so that I can bring some structure to my chess game? I'm looking for something of an absolute beginner's difficulty that goes on to an intermediate level.
Answer: Absolute beginner? My best advice to you would be getting/buying Chess Master Grand Master Edition game. Install the Josh Waitzkin Academy (it will ask you while you're installing it's easy to notice) and go through his tutorial.
It's an interactive tutorial that teaches you how to start thinking as a chess player, it's completely voiced and will have puzzles and questions as it goes from one level to another forcing you to put what you just learned into practice. When you finish the entire tutorial, you should have at the end at least basic knowledge about openings (including some traps and how to avoid them!) middle game tactics and some sacrifices and last but definitely not least basic understanding of end game.
At the start it will even have you slightly practice memorizing the chess board annotations (like where b4 is or any other square) which definitely helps in the long run when you go into higher levels of chess.
After you're completely done with this tutorial and master it (you will most likely watch it more than once throughout your chess career to understand everything completely 100%) there is another course, which is less of a tutorial and more of a high level analysis between a GM and a ferocious Chess machine.
I advise you to not just watch and finish these tutorials but to also go out and play with other people... If there's a chess club out there near you or at least you can reach by bus or something, definitely go there and play against stronger players and you'll improve even faster.
Hope I helped :)
Comment: This program helped me reach the (almost) master level I'm at now, and I still watch the tutorials on a regular basis.
Comment: @Bad_Bishop Same thing, I kept returning to it. Although I am only at Master level at best not even IM yet. Hoping to get there one day... But college sure doesn't give a break :( But yea, you will never regret a penny on that game. It has a full opening database as well, basically it's a freaking gem!
Answer: Regarding videos, there are some very instructive channels on YouTube. For an absolute beginner I would highly recommend Majnu2006. In particular, the playlists "Practical chess endgames" and "Chess middlegame training" are really good for getting a feel for positions where you normally get stuck and do not know what to do. Of course, other playlists are also very good, but for a start, the two mentioned above should do.
Secondly, I would also recommend the YouTube channel of the Chess Club and Scholastic Center of Saint Louis. There you have grandmasters like Yasser Seirawan (a living legend of the game), Var Akobian etc. giving lectures for different levels (beginner, intermediate, advanced). There are lectures on basic concepts, and there are lectures on some famous games, all varying in difficulty level, style and topics, so there is a lot of helpful material to choose from. In my view, Yasser Seirawan is especially gifted in conveying chess knowledge---his ideas are easy to follow and to remember. On top of that, he often tells chess anecdotes, which serve as a nice spice to an already good lecture. In short, he is a very good choice for people who are starting to play chess.
There are several other very good channels, mentioned in my answer here.
Regarding books, it is usually a good idea to learn from the masters. Therefore, my suggestion would be Capablanca's little gem "Chess Fundamentals". As the name says, the book is an introduction to the basic concepts in chess. How suited is the book to your needs depends, of course,  on how seriously you are planning to study chess. As a general advice, though, I cannot think of a better introduction to the magic world of 64 squares.
Enjoy!
Answer: Guide to Good Chess by CJS Purdy
Bobby Fischer Teaches Chess
In order of recommendation. The Purdy book is an easy read, once you get past some of the slang (he's an Aussie and it shows) and covers all phases of the game from a very basic level. The Fischer book is a programmed instruction book, meaning every page asks a question or poses a problem for you to solve, and when you turn the page, the answer is revealed and explained.
The Modern Chess Self-Tutor by David Bronstein
This book is for when you get past either of the first ones. It will demand work from you, but you'll benefit from it for a long time.
Somewhere in between those levels are
Comprehensive Chess Course by Alburt and Palatnik
Secrets of the Russian Chess Masters Alburt and Parr
The first was originally a two-volume set, occasionally the two are bundled together in one volume. Albert wrote 3-4 more books in the series, but don't worry about them for now. The Alburt/Parr two-volume set resembles the first, but is written more for adult self-study (the other was written more for teaching children in a classroom).
Answer: Good Beginner Books:

Winning Chess... series by Yasser Seirawan
The Soviet Chess Primer by Ilya Maizelis
If you can find it: Journey to the Chess Kingdom by Averbakh and Beilin

The last two are considered classics and were the 1st chess books for many great Soviet and Russian grandmasters.


Please Help Me Rollback My Google Docs to the Old Version

Question: In 2010, I created a Google doc using CSS style and Edit HTML features.  This Google doc is a very detailed Specification for one of my projects, and I have spent so much time styling it and making it look perfect.
However, in 2011, I found Google Docs prompted to upgrade to the new version.  I made a copy of the document and tried it out, and it really disappointed me.  So I kept to use the old version.
A week ago, when I opened the document, it was in the new version without my permission, and all my CSS styles were gone, and I could not edit CSS/HTML any more.  The revision history is also gone!!!
Please help me rollback to the old version.
Answer: Goto File -> See Revision History. You should be able to change back to your old revisions from there.
Comment: No, I cannot do that. All revisions are also gone.


Are there ever scenarios where more pawn islands are preferred?

Question: In chess, it is usually advisable to have fewer pawn islands than your opponent. However, while I was watching a youtube video by someone called agadmator chess, he mentioned that multiple pawn islands do have their benefits and I'm trying to understand what kind of benefits or scenarios where multiple pawn islands are an advantageous factor.
Comment: You shouldn't believe everything agadmator says.  He's isn't that strong of a player.  Most of his analysis is just from engines and books.
Answer: Such scenarios arise occasionally in the late endgame.  For example, this position is a win for white (LiChess):
<code>[fen "1k6/8/8/7p/P2P2pK/8/8/8 w - - 0 1"]
</code>
while a similar position (where white has fewer pawn islands) is a draw (LiChess):
<code>[fen "1k6/8/8/7p/PP4pK/8/8/8 w - - 0 1"]
</code>
In the first case, if black's king captures a pawn, the other white pawn promotes (although white needs to play precisely).  In the second case, black's king can stop both from promoting because they're closer together, i.e., because of there being one pawn island.
Answer: More pawn islands is an endgame disadvantage, even a late endgame disadvantage because it means that the side with more pawn islands has more weaknesses to defend.
The obvious advantage to more pawn islands is where one side has made pawn captures creating doubled pawns and half open files which can be used for an attack. These can give a temporary advantage through the late opening and middlegame but later turn in to an endgame disadvantage if the player does not turn his dynamic advantage into either a win or a static advantage.
Such a position can even be an early endgame advantage if it allows fast activation of one or more rooks.
In general there are lots of rules from the time of Nimzowitsch's "My System" which have proved in modern times to be too inflexible. There is an excellent book by John Watson called "Secrets of Modern Chess Strategy: Advances since Nimzowitsch" which reassesses these positional ideas.
Answer: I guess one case would be the outside passed pawn in a pawn endgame.
i.e. if white has two kingside pawns and an a-pawn, and black has three kingside pawns.
In that situation white will be winning usually.
I wouldn't really think about pawn islands there though - it's a useful paradigm for evaluating pawn structures but it's not the only one.


Search results - page size

Question: We have this requirement where it states that after performing search user can change how many items are displayed on results page. How one could achieve this in SharePoint 2010? We think about dropdown or static links to choose 10,15,20 etc.
Answer: You need to create your own SearchResult web part which inherits from CoreResultsWebPart and assigns the value selected (probably transferred through QueryString in URL) to ResultsPerPage
There is a Results Per Page Search Core Results Web Part on Codeplex which you may be able to use

Search results - page size


What extent is non linear dynamics and chaos helpful to study brain function?

Question: Recently I've started reading dynamical systems in neuroscience by izhikevich and was fascinated by the subject. I would like to pursue PhD in computational neuroscience after my masters. Is it worth to choose this area as my Phd topic? or will it lead me to dead end? If possible can some one suggest the leading researchers/labs working in this direction?
Comment: Are you more interested in the neuroscience side of things or in the computation/complex systems side?
Comment: Neuroscience side. Particularly dynamical analysis of biological networks and their behaviour.
Comment: 1) Don't pigeon hole yourself into a particular subfield before you've even made it to grad school.  You have no way of assessing what subfield has the most promise at this point, so don't try.  Leave yourself open to multiple possibilities of good directions to go.
Comment: 2) Dynamical systems and chaos approaches to neuroscience modeling frequently stay too far away from the problems that experimental neuroscience is exploring to be useful for moving forward the broader neuroscience conversation.  If you are interested in computational neuroscience, you should always keep in mind that models are unconstrained by reality, and you need to be in extremely close conversation with experimentalists to stay relevant.
Comment: 3) The great thing about the dynamical systems approach is that learning differential equations is applicable no matter what type of modeling you do.
Comment: I too have had the same thought. Thanks for your suggestions +1 @honi
Answer: Since this an active and relatively new area of research, nobody can tell you for certain where it will lead.
Whether it will "dead end" is perhaps the wrong way to think about it too. All lines of research have their limits, and when those limits are reached, those researchers who found the limits are often the ones best equipped to move on to the next "thing". If you choose to study it and it turns out to be a less productive area than you had hoped, you will still have learned a large set of useful skills that you can apply to other methods.
As for the usefulness of brain dynamics, the short answer is they have their place and are very promising in certain areas of behavioral science. In particular, coordination and motor control appear to be very well suited to these models. A small but growing body of scientists believe dynamics is the next big thing in cognitive science, though it is still unclear whether this is the case. It sounds like you already have a good primer on the utility of nonlinear dynamics for computational neuroscience with what you're reading. For a more general discussion of their promise and potential for other areas of cognitive science, and a proposal that dynamical systems can essentially replace computational neuroscience, see Chemero (2011). For a concise criticism of the approach see Wagenmakers, van der Mass, and Farrell (2012).
1: Chemero, A. (2011). Radical embodied cognitive science. MIT press.
2:
Wagenmakers, E. J., van der Maas, H. L., & Farrell, S. (2012). Abstract Concepts Require Concrete Models: Why Cognitive Scientists Have Not Yet Embraced Nonlinearly Coupled, Dynamical, Self‐Organized Critical, Synergistic, Scale‐Free, Exquisitely Context‐Sensitive, Interaction‐Dominant, Multifractal, Interdependent Brain‐Body‐Niche Systems. Topics in Cognitive Science, 4(1), 87-93.


Transit without visa in Gatwick airport

Question: We are going to come to Gatwick Airport 04.29.2018 at 9.35 pm in the evening to the North Terminal and have next flight in the morning, by EasyJet, 04.30.2018 at 9.05 a.m. to Marocco with all hotel bookings in the hand from the South Terminal. We are planning to have a night in the airport transit zone. Do we need any visas in this case to get from one terminal to another? If some of us have British visas could they take the baggage for the entire group and re-check it? Easy Jet have online ticket. Will it be ok without going outside transit zone?
Comment: Are you saying you have bookings for at hotel at Gatwick Airport? To the best of my knowledge (and google-fu) there is no airside hotel at that airport.
Comment: On the other hand, this means that your assumption that you will arrive in North may also be based on outdated information. Which airline is your arriving flight with?
Comment: Please add your nationality.
Comment: Note that since January 2017, Easyjet uses the **North** terminal at Gatwick. If you're basing your plans on information that they fly from South, beware that it may be outdated.
Answer: It does not appear to be possible to transfer airside between terminals at Gatwick. Note that https://www.gatwickairport.com/at-the-airport/flying-in/flight-connections/ says:

If you need to change terminals, you can take our free shuttle 24 hours a day.

The shuttle they refer to is the landside peoplemover between the North and South terminals.
So in order to reach your departure terminal, you need to enter the UK. Depending on your nationality, where you're traveling from, and which other visas you hold, you may qualify for the UK's landside "Transit Without Visa" scheme, but you have not given enough information in your question to determine that. See this question (and links therein) for details.
Comment: You can check what visa you need, if any, at this [earlier answer](https://travel.stackexchange.com/questions/34106/is-there-a-way-to-find-out-if-i-need-a-transit-visa-for-a-layover-in-the-uk). Might be good to edit into the answer.
Comment: As Ukrainian nationals, _if_ you have to go through Border Control, you will need to obtain Visitor in Transit visas in advance. I'm unable to determine if that is necessary at LGW. I see no way to do it if you change terminals. But perhaps your flights are at the same terminal. (If you get the visa, I see no reason you have to sleep at the airport if you are willing to spend the money on a hotel.)

Transit without visa in Gatwick airport


Best way to transfer Indian rupees to Bank of America?

Question: I am travelling to USA for a stay about 1 year. I have recently opened an account in the bank of America. Now I want to deposit some cash for my stay in the same account. Please let me know the best possible way I can deposit my liquid INR to US$ in the bank of America account.
Comment: This would be better off on the personal finance site.
Comment: @DJClayworth Yes, In case someone thinks monetary factor is not to be included in your travel plan.
Answer: TL;DR: If you have < $1000 - < $2000 worth of money, use a travel card (you can easily get one from Axis Bank) otherwise use a wire transfer for either your Bank Account or from a Forex Service.
I happen to have a BoA account as well, so I do this quite often. In India, in order to transfer money to the US, you have three options,

Use your local bank in which you have an account with all that money in it. If you have most of your money in cash, then your best bet is to deposit this in an account because that's what they will need in order to wire transfer to BoA. This would ideally be the easiest way if your money is already in a bank account. Axis Bank is one of the better bank which you could do this with, because they provide a lot of forex services such as travel cards and all as well.
Use remittance services with a leading foreign exchange service such as Thomas Cook. They might be willing to take cash as well but they might require you to write them a check from a bank account. If you absolutely want to use cash, I think a PAN Card would be required in order to make sure that the cash can be associated to your account for taxation purposes.
Get a free travel card with Axis Bank or any other service and load that with all your money in it and make a withdrawal using any ATM in the US and deposit all the money in your BoA account using the Travel Card.

Now, let's talk about the costs,
Unforunately this depends more on your negotiation skills that anything else, for a small amount i.e < $1000, carrying in your Travel Card would be a better option, otherwise, using one of the two services I mentioned is better.
Now, I have gotten better rates from the bank as well as 3rd party dealers with respect to Forex Bank Transfers but typically for larger amounts i.e > $10000 you are looking at an additional rate of about 0.3 - 0.5%. For the travel card, the rate is usually 1% is the norm.
Note: BoA will charge you about $12 for an incoming wire transfer whereas the banks I mentioned might charge you a flat fee of about $10 or Rs. 500 for both travel cards and wire transfers. As you might expect, these depend on the Bank/Forex Service. If you carry the travel card and you withdraw money from the card, a fee of $2 is usually charged by the withdrawing ATM (in this case a BoA ATM) and of course to deposit the money into your account, (maximum of $800 per transaction in both cases i.e if you have more, then you need to withdraw and deposit multiple times).
Lastly, what documentation do you require,
Simple, all you need is the Swift Code (For BoA USD trasfers BOFAUS3N) of the bank and the Bank Account (either Checking or Saving, any one is OK) number you wish to transfer to and although not required, but the branch of the bank will be additional information which won't hurt. Basically any information which is required to uniquely identify the transaction to your unique account.

To add, I would be highly surprised if you carried a major amount of money outside India in INR. This is not allowed as per the FEMA act and is clearly mentioned on the Reserve Bank of India Website FAQ,

Residents are free to take outside India (other than to Nepal and
  Bhutan) currency notes of Government of India and Reserve Bank of
  India notes up to an amount not exceeding Rs. 10,000 - per person.

More information about the same has also been discussed earlier on this website, check this question, Is it really forbidden to cross the Indian border with Indian rupee?
In case you did though, there is not much you can do with it, because it is ultimately illegal and if you turn up with that sum of money in Indian Rupees anywhere outside India, you will turn heads and you risk confiscation of that money.
Comment: What is the precise meaning of `< $1000 - < $2000`?  Isn't that the same as `< $2000`?
Comment: @Flimzy It's an approximate value based on the difference in exchange rates which you might get. Also for smaller amounts you may not require a PAN Card, but there is no set rule for this as it is specific to the exchange provider.
Answer: If you are still in India, then have your bank wire the funds to your account in the USA.  Not sure what all your bank in India might require, but usually it is the SWIFT code for BoA, your account number and perhaps the branch your account was opened at.
If you are in the USA already, take your cash to the bank.  When I had an account at BoA, they would accept foreign cash for deposit in my account.  It usually took a few days before being fully credited as they had to send the currency to their foreign exchange center and the exchange rate was determined the day it actually made it there.


how can a mirror all of the traffic on a network interface, to virtual interface

Question: I am trying to setup snort to act as an ids, on a debian machine that also functions as a router. Ideally I would like to setup snort in such a way so that I would not have to purchase an additional network adapter just to have it listen to the same traffic that the debian machine is already handling. Having said that, what would be the best way to mirror traffic from an interface, and then send the mirrored traffic over to snort? Or would you recommend that I go along a different route? I was thinking a bridge could possibly work, but I am not sure if that would be the correct solution, any help would be appreciated, thanks!
Answer: In your situation I think we can build out two design options that could likely work.

Run snort on the router directly.
Run snort on a separate box dedicated for this purpose.

Running on the Router
Since you have rolled your own Debian instance for your router, it would simply be a matter of installing, or compiling, the packages for your version/architecture. You could then configure snort to attach to either the inside or the outside interface, depending on which one you want to monitor, and let 'er rip.
This could be easy, would not require adding any more hardware, could be easily reconfigured to run in IDP mode, and would not require any potentially odd network configurations to make work. The biggest downside is going to be performance. Snort can consume an insane amount of resources. It could trivially eat up all the RAM and CPU in a system making your router unable to, you know, route.
Snort has gobs of configuration options. Not just turning on or off rules but whitelisting rules for certain hosts, adjusting the number of bytes of memory used for packet defragmentation, the number of packets to store in memory for TCP stream reassembly, etc. I generally recommend spending an insane amount of time tuning these parameters, and even after you get them set the way you want them to go back and do periodic reviews to see if anything needs to be tweaked.
Running a Dedicated Sensor
This is usually the recommended solution. It solves the network outage problem for resource competition. It allows you to use specially crafted hardware so you can make your sensor do exactly what you want. This will also free you up to add an extra hard-drive to run daemonlogger, or throw in some more RAM without having to deal with scheduling full network outages. It is also more scalable. Sure, I can get snort running on the Pentium 4 whitebox running pfSense at home, but there is no way I will get it to run on a Juniper EX-8216 at work. A purpose built sensor will run just as well in both environments.
The downside is that you're adding yet another system to manage, another box consuming power, more BTU to evacuate, etc. Depending on your network infrastructure it may or may not be easy to get the data into it. The major network vendors all have something to do this. Cisco calls it a SPAN session, Juniper calls it an Analyzer, Enterasys calls it a Mirror. It is possible to perform the same function with iptables using the TEE target, though I don't know any other host firewalls to say whether they can or how to do it. Failing all that you can use a network tap which is a physical device that electrically copies the data stream.
In any case, what you have to do is get a copy of the traffic from your network infrastructure to your sensor. The best way to do this, and the recommended method, is to have two NICs in your sensor: 1 for management and 1 for monitoring. The price of interfaces can vary widely, but unless you're talking about situations with links of greater than 1Gbps, or sustained throughput approaching 1Gbps, cards are pretty cheap. I've been recommending even a simple Intel Pro/1000 GT, the things are $30 and do everything you'll need!
It is possible to run on one interface, but I can't recommend it. You're most likely to run into odd inconsistencies with your monitoring, or potential network issues thanks to the problem of transmitting on a link that is normally expected (assumed?) to be receive only.
There's a fair bit of information available on the snort tag on our sister site for Information Security Professionals.
Answer: When I have run snort, I ran it on the router.  This doesn't require an additional interface to send the traffic to.   The risk is that if snort mishandles data and executes it, it will have easier access to the network than it would have otherwise.
Comment: Hello, when you had snort setup on the router, did you simply tell it to listen on the physical network interface? I am under the impression that snort would try putting the interface itself into promiscuous mode which would then negatively affect network performance/routing, although I could be mistaken.
Comment: You can have snort run in non-promiscuous mode. It is non-default and will cause snort to only process packets destined for the host.