Blacklist the [microsoft] and [apple] tags

Question: As another question already sufficiently elaborated upon, there is absolutely no sensible reason for the tags microsoft and apple (together ~7k questions) to exist. Naming the concrete product involved is the appropriate tagging here, therefore I propose eliminating these tags for good.
Comment: And then there's the ambiguity - say there's an Apple product called Pi, and there's an [apple-pi] tag, if a question is tagged [apple][pi] ([pi] meaning the constant 3.14... obviously), we need to change that to [apple-pi] not just remove [apple] and risk losing what the question is about (many questions exclusively mention languages / tools / products via tags - it's not elsewhere in the question at all, and the tags should be sufficiently meaningful). (I don't know if there exists such a case, so I see it as a bit of a risk).
Comment: @Dukeling I don't know, maybe we could check for non-closed questions that don't have any other tags, but I wouldn't be surprised if there were only few. And if the question itself can't clarify on why it is MS/Apple-related (thus providing enough information to add a useful tag) the question should be closed as "unclear what you're asking" anyway
Comment: Well, we probably shouldn't just remove them from all questions that currently have them, as those questions might not have sufficient other tags and might get lost, so someone will need to go through them manually, so this should probably be a burnination request first.
Comment: @Dukeling That second argument makes sense, though in that case the questions would be a) is there a [tag:pie] tag that has an entirely different meaning (is there e.g. any [tag:excel] but the [tag:microsoft] one?) and b) _should_ the tag be [tag:apple-pie] instead of [tag:pie] (since everyone knows what belongs on a proper pie)?
Comment: Please do note that we haven't been able to get a tag blacklisted in well more than a year.
Comment: Is there no way to blacklist tags moving forward?  Why do we have to retag old questions?
Comment: Hm. Why does it still reference those tags on MSE?
Comment: Might as well blacklist PayPal too while we're at it.
Comment: @TobiasKienzler It's not really / necessarily about **any** other tags, it's more about **some** other not-so-useful or incorrect tags. Too many questions are badly tagged, we can't just go closing all of them even if they're good questions otherwise.
Comment: @Dukeling I'm not sure I can follow you there - how does closing relate to the suggested blacklisting? If you're referring to my previous comment, I can't see how an additional tag [tag:microsoft] or [tag:apple] can fix ill-posed questions. And if they _are_ well phrased, stripping those tags won't break anything
Comment: @TobiasKienzler You mentioned closing... If they have tags like [tag:microsoft] or [tag:apple], there's a decent chance that they aren't properly tagged. There's a fair chance that they are ill-posed as well, but not necessarily, and even if they are, it doesn't mean that, underneath all that, there isn't a really awesome question. So, for these reasons, the questions with those tags needs to be reviewed.
Comment: @Charles It's been a slow year then ;)
Comment: @Deduplicator looks like  a bug, you can report it on MSE. (though it might be caching, so give it a day before reporting)
Comment: @Deduplicator I made a dummy-edit to fix it, though the same applies to the answers - I won't edit them though, so you can report a bug if it doesn't change...
Answer: In general, I would recommend to black-list all the non-programming tags. As Non-Programming questions are off-topic for SO, ie, yahoo hotmail microsoft apple facebooktwitterorkutmyspace blackberrynokia  etc.
For these more specific tags should be included to post. So it is easy to filter out.
Here is more detailed answer.

Things like "Microsoft" and "Apple" are users tagging things incorrectly. The company name is meant to be a part of the tag, like "Microsoft Power Point" would be microsoft-powerpoint, but users type it with a space as "microsoft powerpoint" and it suddenly becomes two tags microsoft and powerpoint. The brand is part of the product name. Though we oftentimes just crop off the brand name because it makes the tag longer and it's not really useful.
The microsoft and apple tags are not useful at all. Microsoft and Apple both have a zillion different products under them, which makes these tags extremely ambiguous at best.
These tags should both be burned to death.
Comment: [tag:facebook], [tag:twitter], [tag:myspace]... is fine. It is about the specific product. (if you ask a question tagged [tag:twitter], I assume that it involves the twitter API). [tag:microsoft] and [tag:apple] are both vendors with a lot of products, so it is not clear about WHAT product this question is, so we need an other tag, which make them both useless. For [tag:nokia] - I don't know enough.
Comment: twitter is a vendor... [Here is list of libraries twitter is maintaining. so its can not twitter-api when u say twitter](https://dev.twitter.com/docs/twitter-libraries)
Comment: Another good example is of a Twitter tag is "twitter-bootstrap".
Comment: The `microsoft` tag has just reappeared. I untagged the 3 questions that were tagged with it seems I'm not trusted to (vote to) delete the tag itself.
Comment: As a reminder to new users who haven't reached the "edit without approval" threshold -- please DO NOT make edit suggestions purely to remove these tags - it requires many more people's effort to then APPROVE those edits.
Answer: Some questions might be about the company themselves, which is when that tag would be appropriate.  If you look at their tag wikis, they are about the corporations, and specifically state to be careful using them.
Comment: I can't think about a valid reason why a question about Microsoft/Apple is appropiate. Maybe you have an example?
Comment: asking about corporation is off-topic.
Comment: I opine that the tag should be [tag:microsoft-mvp] or similar.
Comment: I took the liberty to fix that, since [tag:mvp] is _definitely_ the wrong tag there (also @Colin'tHart)
Comment: I'll try to come up with an example, but there are certainly plenty of historical questions that those tags could be applied to correctly.  ___"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."___
Comment: Here's one that's ok: http://stackoverflow.com/q/926500/13295
Comment: Yeh, that's probably a good call.


How do you deal with off axis mic sounds?

Question: I'm working on a feature film production and trying to figure out how to deal with off axis mic recordings.  Any help?
Answer: If you are talking about isolating the dialog or pfx - removing room sound from the recording:
Ive been trying out NML RevCon-RR recently.  There is another called DyVision Reverb Remover.
If its a pfx (production effect like someone touching, moving, dropping, etc) on set and the boom mic was not pointed at it --- I wouldnt worry about it.  Foley or SFX guys will cover it.  The sound editors will mute out the production track and replace it with a foley/sfx recording and then the mixer will worldize (place it in the room with reverb etc) upon mix stage. If its an ok sound, or a good layer - then the editors will sweeten it, or fill in the missing sonic characteristics. Im probably just spouting stuff you are familiar with by now.
Best solution is to rag on the production team and let them know theres badly recorded sound - JUST KIDDING
Let me know if those plug-ins help!
-C3Sound
Comment: I'll have to check those out.  I was talking about isolating dialogue.
Comment: Where can I get DyVision Reverb Remover? I know, look on the internet and find it. But maybe you know of a place where I can down load it for free.
Answer: I'm also not super clear about what you're asking.  What I'm doing right now (or should be doing instead of surfing SSD) is an EQ automation pass on my dialog tracks.  I have everything automation enabled on my EQ and have set it to write mode.  I go through sentence by sentence and word by word and try to make everything sound consistent.  When I'm done the EQ dances.
If there's a bit of dialog that's off mic and not just off axis then that's another matter.  In the past, there wasn't much that could be done about this other than ADR, or finding another take.  Now there are plugins which claim to be able to remove reverb.  I haven't tried them myself but remain skeptical.
If you're asking about PFX then C3Sound is right.  They should all be split out onto separate tracks and either left as is, sweetened or replaced.
If you're wondering what to do about noises that can't be easily split out well...so am I.  I just asked that very question and hopefully answers will be pouring in soon.  :)
Answer: Can someone define off-axis mic sounds?  I thought it was a mic that wasn't pointed towards the speaker and my imagination was putting together phasing tricks in order to align the audio.
Now that I remember though, off-axis mic sounds are just sounds that aren't supposed to be in the recordings and that is an easy fix or hard fix but its knowledge that I have.
Comment: Off-axis usually refers to what you said first, sounds recorded with the mic at an angle.  In the case of production dialog, it's up to the boom op to keep the mic pointed straight at the talent.  If for one reason or another the mic is not on axis, the frequency content of the voice will be different and will have to be fixed in post with EQ automation.  I would call sounds elsewhere in the room off-mic.
Comment: ohhh ok, very clear now
Answer: To me, off axis and off mic are the same: sounds that are outside the pickup pattern of the mic and therefore weaker in certain frequencies, regardless of whether they're signal or noise.
C3Sound has some good ideas for improving on this.
If you're talking about undesired sounds over dialogue, it's better to fix this with editing/ADR than processing. Going through alternate takes is a good first step, then spotting and recording ADR.
"Audio Post Production for Film and Video" by Jay Rose has a pretty cool chapter on dialogue editing.


Are US Senate/House rules legally enforcible?

Question: Suppose, for example, that the Senate is considering the passage of a law. A Senator has decided to open a filibuster. After a half hour, the majority leader tires of hearing this Senator speak. He motions for an end to the filibuster, but is only able to get 51% of the vote. According to Senate rules, I believe, you need a 2/3 vote to end a filibuster. Over said Senator's objections, the majority leader begins the voting process and the bill gets 51% yeas.
Comment: Such a thing could very plausibly happen. The Senate has already used a very similar procedure to confirm judges by majority vote instead of the 3/5 needed to end a filibuster. Take a look at https://en.m.wikipedia.org/wiki/Nuclear_option for more information.
Answer: Generally not. Federal court uses a principle known as the enrolled bill rule -- in deference to the coequal status of the three branches of government, the "enrolled bill" (the thing printed on fancy paper that actually went to the President for signature) is irrebuttable evidence that the law was properly passed. The courts cannot deal with inquiries into whether legislative process was followed; it's the legislature's job to decide what the right process is. They can't even look into whether the same text passed both houses -- as a matter of law, the enrolled bill is conclusive evidence that it did.
Senate rules are enforceable in the Senate. But the Senate is the body in charge of enforcing them, not the courts.
Comment: "They can't even look into whether the same text passed both houses -- as a matter of law, the enrolled bill is conclusive evidence that it did." But according to the Constitution, a law must pass BOTH houses before being sent to the President. So if the Senate decides to skip the House and send the bill off to the President, and the President signs the bill, then the bill CANNOT become law. You'd think the judge would throw out the bill in its entirety if someone can prove that the House didn't pass the bill.
Answer:
The senate can change their rules at any time by a majority vote.
60 (3/5) votes are required to end a filibuster (with the exceptions of federal judge nominees (1/2) and rule change motions (2/3)).

So, for your hypothetical to occur, there needs to be an intermediate step where a majority agrees to change the rules to allow a simple majority to cloture the filibuster.
Generally speaking, the senate has resisted changing the 60-vote filibuster rule (with the above mentioned exceptions) because the supermajority requirement protects the interests of the minority party.
Every senator understands they can be in the minority depending upon the outcome of the next election every two years. (Even though each senator is elected every six years, elections are held for 1/3 of the senate every two years.)
Therefore, the filibuster rule protects the interests of all the senators. Which is why they haven't eliminated it and are unlikely to change it for the passage of any particular bill. Although, theoretically, it could happen.
Comment: Special case: cloture on a motion to change Senate rules requires 2/3, not 3/5.
Comment: I've never seen "cloture" used as a verb before.  Do you have any reference supporting it?
Comment: @phoog: http://dictionary.reference.com/browse/cloture
Comment: Belated thanks for the reference.  I'd still prefer _to close,_ however. :-)


IQ test question

Question: How would you solve these? I would pick option 1, second row for the first one but I can't seem to find a comprehensive explanation for it.
Comment: I've _definitely_ seen that second IQ question (or something like that) somewhere on this site (or maybe somewhere else).
Answer: For the first one I would think

The 3rd option

Because

The first row has triangles (3 sides) and a total of 3 dots.
The second row has squares (4 sides) and a total of 4 dots.
The last row hos a 5 sided shape and 4 dots so far, so the answer should be the same shape and have 1 dot. There are only one option that fits this.
Answer: #1, I would choose

  /\
 |  |
 |__|°

because

 each pattern in the 3rd column has one dot, outside the shape.
 or, alternatively, because the major diagonals of the grid have dot counts 1,2,3 from top to bottom.

#2, I would choose

 _____
|   ° |
|     |
|_____|

because

 each row of patterns shows a time sequence of the ball bouncing around the inside of the square.

Of course, as is the norm for these types of puzzles, there will be a multitude of interpretations that work to explain almost any of the possible answers.
Comment: Blegh, imo these "iq tests" are more like "guess what I'm thinking" questions, in which increase in difficulty is an increase in broadness...
Comment: Another reason for thinking your answer to 1 is correct: the triangle row has three balls and a triangle has three sides; the square row has four balls and a square has four sides; with the single ball house, the house row has five balls, the same number of sides as the house. Bah humbug on these questions.
Comment: for the first one, the left column would seem to be a counterargument to your argument about the right column.
Comment: Not really. Each column could have its own rule; for example, the left column's rule may be "always one dot outside the shape", and the middle column's rule could be "any dots are inside the shape".  The fun/annoyance of these is that with so few examples that your explanation needs to fit, with relatively little effort you can make almost anything into a pattern.  As it is, each row arguably has its own rule anyway - row 1, shape=triangle. row 2, shape=diamond. row 3, shape=house.  so there's no reason why columns can't also have a unique rule each.
Comment: If there is a "best answer", though, it will be one in which the whole 3x3 grid follows a pattern.  In other words, either all columns have the same rule, or the rules for the columns (if indeed they have rules when taken in isolation) evolve in some natural way from left to right.
Comment: ^vote for the dynamic interpretation of #2

IQ test question


How do I avoid wrinkles in dress pants placed on a hanger?

Question: I am constantly using dress pants for work or other events. I iron these pants in advance, and sometimes, they ended up with a wrinkle because of the hanger's curvature. Is there any type of hack that I can use, so I can hang the pants in a way that the curvature of the hanger does not create a wrinkle?
Comment: Uh, use an un-bent hanger?
Comment: Could you post a picture of the hanger?
Answer: Option 1: Use pants hangars
Not a hack, but they make hangers designed for this. Assuming your closet is tall enough, you can just let them hang down fully without the fold. If you don't want to buy one, you can fashion one yourself out of a regular hangar and a couple clothespins. The idea is to just clip the waist to the hangar.
Option 2: Duct tape
The main reason you get a crease is because the hangar is too thin, and it's creating a fold. You can thicken it by wrapping it in something. Sure you could use cloth or something else, but duct tape is normally on hand (at least in my experience). Try to wrap it as smoothly as possible. If you can get the hangar bar to a half-inch or more diameter, you shouldn't have much of a problem with wrinkles.
Answer: Cut a piece of pipe insulation the length of the horizontal bar on the bottom of the hanger. Since the pipe insulation is already slit along the length the insulation, it will slip right onto the bar and stays on the bar without any further taping required.
Answer: As already pointed out a thicker hanger is better, many dry cleaners use metal hangars but place a folded piece of card over the bottom wire to make them effectively wider.
The other trick is rather than folding both legs together over the wire place one leg over the wire from one side and the other leg from the other side. This allows the trowsers to be hung a little lower as the top leg secures the bottom so you do not have to have the weight 50:50 and can align the bar at knee hight - where you tend to get a crease when walking, etc.


Copy contents of text file in document library to SQL table

Question: After I upload a text file to a document library I would like to copy it's contents to a SQL table.  How can I extract the contents before or after it gets in to the document library using workflow?  I've run out of ideas.
Answer: You can hook into different event receivers that are triggered by item/document creation, updating and deletion.
These events fire before (synchronously) and after (asynchronously) the document is created, eg. ItemUpdating, ItemUpdated.
Be aware that adding documents will trigger both creation and update events, depending on checkin policies, and since provisioning of documents are split up in adding the binary document and adding meta data.
Read more here:
http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spitemeventreceiver(office.12).aspx


How to Start from a Blank Slate with SIM

Question: So whenever I start a new project using the SIM or even a manual installation, I find myself having to remove a bunch of Sitecore Sample data from the Sitecore Master database.  Is there a way to automatically remove this data?  So that you can start from a blank install each time.
Comment: What are the sample items are you removing?
Comment: The Sample Sitecore items: Sample Home, Sample Layouts, Sample Workflow, Sample Renderings/Sublayouts, Placeholder Setting, all the Templates that drive those Items.  Basically the goal is a blank slate of Sitecore so I can setup the structure I need from there.
Answer: There are no steps in SIM to clean the default items from the install of Sitecore. You can create a package containing a Post Deploy Step that will delete any items you wish though and add this as a Custom Package in SIM.
Create the following Post Deploy Step:
using Sitecore.Configuration;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Install.Framework;
using Sitecore.Web;
using System.Collections.Specialized;

namespace Sitecore.CleanSlate
{
    public class PostStepDelete : IPostStep
    {
        public void Run(ITaskOutput output, NameValueCollection metaData)
        {
            var parameters = WebUtil.ParseParameters(metaData["Attributes"], '|');

            Database db = Factory.GetDatabase(parameters["database"]);
            string[] items = parameters["items"].Split(',');

            foreach (var i in items)
            {
                Item item = db.GetItem(i);
                if (item != null)
                {
                    Log.Info("Post Install Delete : " + item.Paths.FullPath, this);
                    item.Delete();
                }
            }
        }
    }
}

Then create a package using the Package Designer.

From the ribbon, select Files statically and add the DLL containing the Post Deploy step
From the System section, enter the details of the Post Deploy step, e.g. Sitecore.CleanSlate.PostStepDelete, Sitecore.CleanSlate
Add the database and items to delete as attributes, e.g.

database : master
items : {110D559F-DEA5-42EA-9C1C-8A5DF7E70EF9},{4D8A1C4D-1351-4DD1-A502-0660F01FEDC7},{14030E9F-CE92-49C6-AD87-7D49B50E42EA},{1936B96E-DA1F-4A3A-8AAF-8C46268E2D84},{9EB73C4C-1AF7-47C7-85B8-93E08176D4D2},{CE4ADCFB-7990-4980-83FB-A00C1E3673DB},{885B8314-7D8C-4CBB-8000-01421EA8F406},{8AE1C245-A4FA-46AE-9B35-4FBC15F63169},{73BAECEB-744D-4D4A-A7A5-7A935638643F},{A5BC37E7-ED96-4C1E-8590-A26E64DB55EA}

Generate the package zip

When installing Sitecore using SIM, on the Custom Packages step Add Package and select the zip that was generated earlier and then continue the install as normal.

This is not a SIM specific package, installing it via the Sitecore Installation Wizard will also produce the same result.
What does this delete?
The package has been tested with Sitecore 8.1.3 and 8.2 but it should work with most versions of Sitecore since the item guids should be the same across all versions but please verify if you're on a different version.
The guids specified as the items in the attributes relate to the following items:
{110D559F-DEA5-42EA-9C1C-8A5DF7E70EF9}    // /sitecore/content/Home
{4D8A1C4D-1351-4DD1-A502-0660F01FEDC7}    // /sitecore/media library/Default Website
{14030E9F-CE92-49C6-AD87-7D49B50E42EA}    // /sitecore/layout/Layouts/Sample Layout
{1936B96E-DA1F-4A3A-8AAF-8C46268E2D84}    // /sitecore/layout/Renderings/Sample
{9EB73C4C-1AF7-47C7-85B8-93E08176D4D2}    // /sitecore/layout/Sublayouts/Sample Datasource Sublayout
{CE4ADCFB-7990-4980-83FB-A00C1E3673DB}    // /sitecore/layout/Sublayouts/Sample Inner Sublayout
{885B8314-7D8C-4CBB-8000-01421EA8F406}    // /sitecore/layout/Sublayouts/Sample Sublayout
{8AE1C245-A4FA-46AE-9B35-4FBC15F63169}    // /sitecore/layout/Placeholder Settings/content
{73BAECEB-744D-4D4A-A7A5-7A935638643F}    // /sitecore/templates/Sample
{A5BC37E7-ED96-4C1E-8590-A26E64DB55EA}    // /sitecore/system/Workflows/Sample Workflow

Add or remove items as required.
Package Download
You can download the package containing the above from here:
https://github.com/jammykam/Sitecore.CleanSlate/tree/master/Module
If you wish to edit the list of items, then open Sitecore.CleanSlate-1.0.0.zip package using an archive tool like 7zip, extract Sitecore CleanSlate.zip\package.zip\metadata\items file, edit using a text editor and then replace the modified file into the archive.
Comment: This in my opinion is the most elegant solution.  Because if there's a situation where I don't want a blank slate, I can choose to note install that package.
Answer: Option 1
SIM uses a zip archive of the Sitecore root folder, so a simple way to do this would be to take the version of Sitecore you want to setup, install that with the basic options.
Next open up Sitecore and delete all the sample content you do not want. Open SQL Server Management Studio and detach the Core & Master databases.
Finally, locate the original zip file containing the Sitecore root folder for your version and unzip it. It will contain 3 folders:
\Data
\Databases
\Website

The Databases folder contains the detached MDF and LDF files, so add your updated database files and then re-zip the archive with the same name.
Now when you install that version, it will be using the updated databases with the sample data removed.
Option 2
Make Sitecore PowerShell Extensions part of the default options for installing and write a script that will remove all the sample data.
To remove an item you can get it by ID and call the Remove-Item cmdlet:
Get-Item master: -ID "{your-guid-here}" | Remove-Item

So get all the paths or ID's of the sample items and create a script to remove them all, run that script once the install is complete.
Answer: I'd suggest your "blank slate" need not be so blank at all. So I'm guessing here; but after cleaning out the items and templates you mention, wouldn't you normally proceed to set up a set of folders and items - which remain much the same for any solution?
Even if you don't; I would propose you solve what you're trying to achieve here using Unicorn. Basic principle would be this:

Install your vanilla version using SIM
Set up Unicorn for the solution, call the configuration something like "Clean"
Add all of the target areas e.g. \sitecore\templates\sample and so on to Uncicorn configuration
Initialise Unicorn (Serialize All).
Proceed to delete and remove all the sample items

Now you have a root Unicorn folder, with your "Clean" configuration root folder, and all of the empty root folders of the configuration. Zip that up or copy it somewhere along with your "Clean" config. Next time, all you need to do is drop Unicorn into your solution with your config, run "sync" and voila.
Now for just "cleaning out" sample stuff, this method is likely a bit overkill. But assuming that:

You use Unicorn for your projects
You have additional steps you always take, after cleaning out sample items

Then just expand upon the steps above. You'll end up having a Unicorn configuration, your preferred "startup items" all set up. Saves a lot of initial time.


A step in zeta function regularization

Question: I'm just wondering about the mathematical step
$$\sum_{n=1}^\infty n\exp[-\epsilon n\sqrt x]=\frac1{\epsilon^2 x}-\frac1{12}+\mathcal O(\epsilon).$$
Why is this equality so? I see that
$$\sum_{n=1}^\infty n\exp[-\epsilon n\sqrt x]=-\frac1{\sqrt x}\frac{\partial}{\partial\epsilon}\frac{1}{1-\exp[-\epsilon\sqrt x]}\simeq-\frac1{\sqrt x}\frac{\partial}{\partial\epsilon}\frac{1}{\epsilon\sqrt x}=\frac1{\epsilon^2x}.$$
But how about the $-\frac1{12}$?
Answer: \begin{align*}
\sum_{n=1}^\infty n\exp[-\epsilon n\sqrt x]
&=-\frac1{\sqrt x}\frac{\partial}{\partial \epsilon}\frac{1}{1-\exp[-\epsilon\sqrt x]}\\
&=\frac{\exp[-\epsilon\sqrt x]}{(1-\exp[-\epsilon\sqrt x])^2}\\
&=\frac{1}{\exp[\epsilon\sqrt x]-2+\exp[-\epsilon\sqrt x]}\\
&\simeq\frac{1}{\frac2{2!}(\epsilon\sqrt x)^2+\frac{2}{4!}(\epsilon\sqrt x)^4}\\
&=\frac{1}{\epsilon^2 x}\frac1{1+\frac1{12}\epsilon^2 x}\\
&\simeq\frac{1}{\epsilon^2 x}(1-\frac1{12}\epsilon^2 x)\\
&=\frac1{\epsilon^2 x}-\frac1{12}.
\end{align*}
Answer: The geometric series formula tells us
$$
\sum_{n=1}^{\infty} e^{-\epsilon n\sqrt{x}} = \frac{e^{-\epsilon \sqrt{x}}}{1-e^{-\epsilon\sqrt{x}}}.
$$
The derivative with respect to $\epsilon$ of the left hand side gives $-\sqrt{x}$ times your sum. Therefore your sum is equal to
$$
-\frac{1}{\sqrt{x}}\frac{\partial}{\partial\epsilon}\frac{e^{-\epsilon \sqrt{x}}}{1-e^{-\epsilon\sqrt{x}}}
$$
which I believe is equal to
$$
\frac{1}{4\sinh^2(\epsilon\sqrt{x}/2)}.
$$
At small $\epsilon$ this diverges like $\frac{1}{x\epsilon^2}$.
Multiply it by $\epsilon^2$ to get something that is finite as $\epsilon\to 0$, do a Taylor series in $\epsilon$, and then divide back by $\epsilon^2$.
Doing that: Let
$$
f(\epsilon) = \frac{\epsilon^2}{4\sinh^2(\epsilon\sqrt{x}/2)}
$$
$f(\epsilon)$ is $\epsilon^2$ times the sum you want to compute. Since the denominator goes to zero proportionally to $\epsilon^2$ for small $\epsilon$ (by the small angle approximation for $\sinh$), $f(\epsilon)$ is finite in the limit $\epsilon\to 0$. In fact, with the definition that $f(0)$ is equal to $\lim_{\epsilon\to 0}f(\epsilon)$, $f$ is analytic at $\epsilon=0$. So let's do a Taylor series for $f(\epsilon)$, expanding it in increasing powers of $\epsilon$:
$$
f(\epsilon) = f(0) + \frac{1}{2}\epsilon^2 f''(\epsilon)|_{\epsilon=0} + O(\epsilon^4)
$$
(There are no odd powers since $f$ is even under $\epsilon\to - \epsilon$.)
The value of $f(0)$ is
$$
f(0) = \lim_{\epsilon\to 0} \frac{\epsilon^2}{4\sinh^2(\epsilon\sqrt{x}/2)} = \frac{1}{x}
$$
by the small angle approximation or L'Hopital's rule, whichever you prefer. The second derivative of $f$ is (according to Mathematica)
$$
f''(\epsilon) = \frac{-2+2\epsilon^2 x + (2+\epsilon^2x)\cosh(\epsilon\sqrt{x})-4\epsilon\sqrt{x}\sinh(\epsilon\sqrt{x})}{8\sinh^{4}(\epsilon\sqrt{x}/2)}
$$
This looks like it diverges as $1/\epsilon^4$, but you can check that the numerator is in fact fourth order in $\epsilon$ as well:
$$
-2+2\epsilon^2 x + (2+\epsilon^2x)\cosh(\epsilon\sqrt{x})-4\epsilon\sqrt{x}\sinh(\epsilon\sqrt{x}) = -\frac{x^2}{12}\epsilon^4 + \frac{x^3}{90}\epsilon^6 + O(\epsilon^8)
$$
so the second derivative is finite at $\epsilon=0$ (If it wasn't, I would have been lying when I said $f$ was analytic) and given by
$$
f''(0) = \lim_{\epsilon\to 0} f''(\epsilon) \\
= \lim_{\epsilon\to 0} \frac{-\frac{x^2}{12}\epsilon^4}{8\sinh^{4}(\epsilon\sqrt{x}/2)}\\
=\lim_{\epsilon\to 0} \frac{-\frac{x^2}{12}\epsilon^4}{\frac{1}2 \epsilon^4x^2}\\
=-\frac{1}{6}
$$
So the Taylor series for $f$ is
$$
f(\epsilon) = \frac{1}x - \frac{1}{12}\epsilon^2 + O(\epsilon^4)
$$
Remember that $f(\epsilon)$ was $\epsilon^2$ times your divergent sum. So the expansion in powers of $\epsilon$ of your divergent sum is
$$
\frac{f(\epsilon)}{\epsilon^2} = \frac{1}{\epsilon^2 x} - \frac{1}{12} + O(\epsilon^2)
$$
"Thus" the dimension of spacetime for bosonic strings is $26$.
Comment: Thank you! I'm mostly wondering about where the -1/12 comes from actually. Could you please expand on that?
Comment: Sure: see my edit

A step in zeta function regularization


How to dress for biking 3 miles to work in 40°F (3°C) and below so not to sweat to much but still keep warm

Question: I bike to work. It's about 3 miles. I live in Minnesota. It is getting cold. When it is like 40 and below I bundle up but I sweat  and then I am hot so I lose a layer and then freeze. Should I wear like a windbreaker or that under armor stuff? I get to work and my body can not tell if its freezing or sweating.
Comment: Hi William. Your question has a few answers, but to me it's not clear. You are riding 3 mi (5 km), in temperatures 40°F (~4.5°C) and lower. What isn't stated is how fast you are riding (it makes a *big* difference), and whether you expect to be riding in rain or snow. Apparently the [climate of Minnesota](http://en.wikipedia.org/wiki/Climate_of_Minnesota) varies according to how close you to are the lakes, so it would help to know where you are.
Comment: I used to commute to work 10 miles each way (25 when I took a "short cut" some mornings).  This in southern MN (near Rochester).  Down to 45-50 I'd generally wear T-shirt and running shorts.  Below that I'd slip on a pair of sweatpants and a sweatshirt -- easily removed (and shoved in my pannier) when I warmed up and needed to be cooler.  For temps below 30 or so I had wind pants & jacket.  Would commute down to about zero.  (I don't commute any more after I changed jobs and it became less convenient.)
Comment: A little on the terrain here will help us.  For me I'm doing jeans, flannel shirt, and light gloves.  I'm still chilly when I leave, but I do a lot of climbing so I still end up sweating by the end.  I get a few good downhills to cool off on but start climbing up again.  On the way home though all this is required not to freeze to death on the downhill.  At 5 miles it would take longer to stop and adjust clothes (beyond unbuttoning shirt) than the whole ride itself.
Comment: As others have said, gloves are important when you get below about 40F.  Start out with plain riding gloves, then polypropylene "glove liners" under the riding gloves when temps get to 40, then something like lightweight ski gloves when the temp is below 15F or so.  (And I have a pair of the polypro glove liners in the pockets of every jacket I own.  They're cheap, light, incredibly warm for the weight, and extremely handy to have in many situations off the bike.)
Answer: It depends a lot on you. I live in Illinois and I'll go out in a T-shirt and shorts in the 40's for bike rides.
But if you want some additional warmth in the around 40F and 3 miles, I'd say maybe some thin gloves (I have a set of Underarmour coldgear running gloves which are useful for longer rides in the 30s) and a hoodie - you might be cold for the first 2-3 minutes but then you'll feel fine. If you find that a hoodie leaves you cold for the whole ride, maybe add a wind breaker with some ventilating holes.
In general, you shouldn't dress enough to feel warm when you're getting on the bike. You'll generate some extra heat, so in most cases, the right amount of clothing will make you feel a bit cold for the first few minutes.
A ski jacket is way too much bundling for riding in 40 degree weather (given that its probably overkill for even just standing outside).
Comment: The bit about "don't dress so that you're warm when you get on the bike" is crucial. That's the fast road to overheating.
Answer: I find that at warmish cold temperatures like the 30s-40sF, the most important thing is to keep my hands and ears warm; the rest of my body takes care of itself after a few minutes of riding. (I am assuming your normal garb does not leave exposed skin other than hands and head/neck. If it does, well, fix that first.)
Have a good pair of wind-stopping gloves; experiment with glove liners if the gloves aren't enough. A fleece earband keeps my ears and forehead warm and doesn't get in the way of my helmet, but if that's not enough or your nose complains, try a hoodie, stocking cap, or balaclava.
You may find that keeping the wind from stripping heat away is plenty enough for the rest of your body, in which case a standard rain jacket or nylon windstopper will do the job. If it doesn't, try a hoodie or put on a fleece vest or jacket under the rain jacket. (A water-resistant jacket with fleece lining is essentially this; Land's End carries such, among others.)
Other minor considerations: Sleeves that are snug at the wrist (e.g. stretchy knit cuffs or buttoned cuffs) keep the wind from sneaking up your forearm. Crew or longer socks do the same for your ankles and calves, or failing that, a cycling cuff-band.
Comment: Keeping the hands warm is must, it will make you uncomfortable and affects your reactions.  The rest of this answer is good as well.  I generally don't require ear coverage at this temperature, but I do long pants (jeans), t-shirt with a flannel over, and gloves (thin leather driving gloves).  I do get too warm though, but 300-400 feet of climbing in 3 miles will do that.  If it rains though, I just get wet.  I'm only out for 30 minutes and hill climbing.
Comment: I have ears that stick out a bit. ;) Round about the low 40sF cold ears start getting distracting for me. YMMV!
Answer: I've found that "soft shell" garments work really well in that temperature range as long as it's not raining. Soft shell fabrics are jack of all trades. They are much more breathable than your typical nylon shell, they are more windproof than a microfleece and with a good DWR they are reasonably good at repelling light rain and snow.
My favorite fabric of this type is Schoeller Dryskin, but it's kind of pricy. Polartec Powershell also works pretty well.
IMHO, you want to avoid anything that claims to be waterproof/breathable. Even the best versions of these kinds of fabrics are not breathable enough for moderate exercise. WB fabrics (i.e. goretex) have their use, but they are vastly oversold.
Answer: My commute has always been about that distance, and when temperatures reach around freezing point, I simply wear a ski jacket which has ventilation shafts under the armpits. Opening these helps me a lot from sweating, and you can easily adjust them. Also thin (e.g. running) gloves can help: they break the cold wind, but allow you to transpire.
And finally, like in warm weather: don't rush too much.
Answer: 5 degrees celsiusis is chilly and the main enemy is wind.
Those are the areas of the body, that generate a excessive heat:

torso
head
thigh

Those are the areas, mostly affected by wind:

knees
palms
front part of the body: breasts, neck, face

I would wear:

no backpack
knee pads, thin gloves
wool shirt with long sleeves
helmet

In colder weather (below freezing) I would add:

wind breaker
winter gloves
ski mask
long trousers

At below -20C I would add:

ski jacket ;p
Comment: In English, corpse typically refers to a dead body. Tights=legs?
Comment: Used to be you could get a "helmet liner" that was a lightweight fleece or polypro cap that fits inside the helmet and attaches to the straps.  Good to have below 15F or so.  Haven't seen then of late, though.
Comment: They still exist - look for skull caps, or you can find ones built into certain helmets like those made by Bern.
Comment: Something like [this](http://www.dx.com/p/santic-c9006-outdoor-cycling-cs-nylon-spandex-face-mask-black-269343#.VDzCRBZY4Q0)? The throat needs to be protected as well.


Fixed Point of a affine non-expansive Operator

Question: For a complete normed Space $V$ let $T:V\rightarrow V$ a linear continous map and $x_0 \in V$. Given $\lVert T^4 \lVert <1$, i.e $\lVert T^4x\lVert<\lVert x\lVert \ \ \forall x\in V$, show that the equation $Tx-x=x_0$ has a unique solution.
It's quite easy to show that the solutions is unique: Let $x,y$ be solution to the equation. Hence $T(x-y)=x-y$ and $T^4(x-y)=x-y$, which implies $\lVert T^4\lVert \geq 1$.
But how to show the existence? The Problem is equivalent to the fixed point problem $Ux=Tx-x_0=x$ of the affine Operator $U$. But I don't know if $U$ is a contraction.
I'd be greatfull for advice
Answer: $x=(T-I)^{-1}x_0$.
You just need to know that $1$ is not in the spectrum of $T$.  The spectral radius of $T$ is $\lim\limits_{n\to\infty}\|T^n\|^{1/n}$, and
$$\lim\limits_{n\to\infty}\|T^n\|^{1/n}=\lim_{n\to\infty}\|T^{4n}\|^{1/(4n)}\leq \lim_{n\to\infty}(\|T^4\|^n)^{1/(4n)}=\|T^4\|^{1/4}<1.$$


Mailmerge token syntax

Question: Please could someone tell me what is wrong with the following
Dear contact.nickname Thank you.
I know that brackets need to be used.
Answer: Yes you need brackets: the curly { } kind
When composing a mail mesage - hit the Insert token button on the right - select the one you want - and it will insert it in the text (where your cursor was located) - including the { }
Answer: Note that nickname is an optional field for each contact.
If you use "Dear {contact.nick_name}," then contacts who do not have a nickname defined will end up with "Dear ,".
I suggest using {contact.first_name} instead.
If you really want to use nicknames, you could create hooks to define a new token, e.g. contact.nick_or_first_name, and populate it with nickname if it is not null, or else first name.
Comment: Thank you very much. The problem was the absence of the underscore between nick and name. I had been mislead by the inconsistent display names. What I have been doing is using the token 'email greeting' This enables me to use a nick name when the prefered salutation is not first name. I encountered the syntax problem when customising the email greeting.
Answer: If you are on a screen that offers 'tokens' in top right, eg on 'send email' or 'new mailing' etc then you can just type in 'nick' and it will offer you the relevant token(s) and then you will get the spelling correct automatically.
Answer: I used a custom token (based on Coleman's blog post) to look and see if there is a nickname. If not it will default to first name.
https://civicrm.org/blog/colemanw/create-your-own-tokens-for-fun-and-profit
So I can use the nick_name token without worry it would be a blank field.

Mailmerge token syntax


Changing PS fluid on 2006 Honda Pilot

Question: I have a 2006 Honda Pilot in need of power steering fluid change. I do not know the type of power steering fluid in there currently. I've purchased a synthetic. Is it OK to mix power steering fluids if I don't know the type currently in there? Can I use synthetic in a 2006?  I'm a novice so go easy on the responses. Thank you.
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Comment: This previous post applies to yours as well
https://mechanics.stackexchange.com/questions/40533/genuine-honda-power-steering-fluid-do-i-have-to-use-this
Comment: Please tell us which specific synthetic product you are hoping to use.
Answer: Honda has specific power steering fluid. You don't have to go to a Honda dealership to get some, but you do need to use the specific fluid. I don't know the differences between generic fluid, or even the synthetic fluid you've bought. I don't know what's going to happen to your power steering system if you use the synthetic fluid. I just know it's not specified for your system. If you Google for Honda Power Steering Fluid you should be able to find all kinds of examples. This goes for both Honda and Acura power steering systems.
Comment: @Msauce If you use the non-Honda spec fluid, your pump will likely squeal. It depends on the quality of the fluid. The use of incorrect fluid is the primary reason for Honda/Acura pump failures.
Answer: So long as the colour of the two liquids are the same, you're usually okay, though this is a massive minefield of opinion-based blasting of theoretical perfect practices versus realistic outcomes.
Mixing two different power steering fluids is a bad idea, though in some cases where well experienced mechanics do it, it's often to do with the age and state of the system; Some mechanics can know whether a specific blend of the two would be beneficial and safe to use.
Should be fine in your era of vehicle. A cool note about your car, by the way, is that in the UK, it's called a Honda CR-V. Looking online at the spec sheets, synthetic should be suitable.
Some cars use a different type, though I'm not so certain how many different types there are, despite being a mechanic for a while, lol. Just make sure to cycle the fluid through the whole system; Top off the PAS bottle and turn the wheel lock to lock a couple of times and check the level again. Repeat again; if you see drop for that second time, you may or may not have a relatively serious leak.  If it's just a change, make sure that you buy more fluid than you'll need; Try and get out any of the old fluid you can from the filler bottle and fill with new fluid. Open the valve at the PAS (not sure how it's set up on those cars) and then cycle fluid through, checking it's got enough in the filler bottle and keep cycling it through until it's coming out with the fresh fluid.
Good luck!
Comment: The CR-V uses the same subframe as the Civic, it's a lifted car. The Pilot is closer to a traditional truck but has a spaceframe. It has strengthening rails to supprort light truck work.
Comment: Also, you should never make judgements on color. Easiest example is brake fluid, they're all clear, but they have very different boiling points and properties. Use the wrong fluid (the right color, clear) and you're gonna have a massive brake failure when it over heats and blows a hose.
Comment: @yollooool - In the States, the [CR-V is a small crossover SUV](https://www.caranddriver.com/honda/cr-v) while [the Pilot could be considered a mid-sized SUV](https://www.caranddriver.com/honda/pilot).
Comment: In the US the Pilot and CR-V are two different trucks.
Comment: Hmmm, that's interesting. I guess the Pilot is either a higher-/lower-spec version of the CR-V or vica-versa.
Comment: Im pretty sure the frames are different too the body is different for sure.

Changing PS fluid on 2006 Honda Pilot


Why does TAS increase as altitude increases and why does my C-152 POH seem to contradict this?

Question: I remember learning and memorizing that TAS increases as altitude increases, however I don't understand why. Especially since my C-152's PoH seems to indicate the opposite in the cruise performance section. Can someone please explain what I'm misunderstanding here?
Comment: "I remember learning and memorizing that TAS increases as altitude increases, however I don't understand why."-- do you mean when IAS is held constant, or what?  When the throttle position is constant?  When the horsepower output is constant?  In questions like this, it is always important to say what the constraint is, i.e. what variable(s) are being held constant.
Comment: . . . and AlexK I think you raised a very good question regarding the POH values of TAS reducing. If something looks wrong, don't wish it away, try and figure it out.
Comment: Welcome to Av.SE!
Answer: Imagine that IAS measures the number of air particles hitting your aircraft per second. As you get higher the air is thinner — there are progressively fewer air particles around the higher you go so to get the same number of particles hitting you per second (ergo the same IAS) you need to move faster through the air - your TAS increases.
Comment: @PeterKämpf to clarify, at no point did I address the specifics of calculating dynamic pressure with altitude. Pedagogically, I am explaining only in simple terms to try and target the estimated level of understanding required to aid the questioner's mental model. I have supposed them to be a new or student pilot without the requisite training to jump directly to the maths, if it turns out to be incorrect I apologise for the disservice!
Comment: You have explained the difference between IAS and TAS, but you haven't explained why TAS is higher at high altitude.
Comment: Roger. I added that the air gets thinner as you go up.
Comment: With that explanation speed should change with the inverse of density when in fact it changes with the square root of that inverse. I think there is still room for improvement. Hint: The [Newtonian impact theory](https://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html) only works for very high Mach numbers.
Answer: To the extent that 75% cruise power available is constant with increasing altitude, it's simply that TAS goes up because the constant HP has less and less resistance to work against as the air thins out, while you are able to maintain 75% cruise power by opening throttle more. On a non-turbocharged engine, that is possible up to the point at which the engine is maxed out making cruise power (75%), somewhere around 8000 feet give or take (where the available manifold pressure at wide open throttle drops to about 22").
At this point the engine is wide open throttle just to make 75% power and is maxed out there. As you go above 8000 ft with wide open throttle, by the time you get to 10000 ft it can produce only 68 thrust HP (per the chart, in standard conditions) with wide open throttle and maximum TAS drops to 103 kt.
If the engine had turbocharging, it would be able to maintain 75 HP (75% of 100) to some much higher altitude and you could climb to say, 15000 ft, still making 75 HP in the even thinner air thanks to the turbo, and your TAS would be up to something like, say, 115 kt (you would also need a constant speed prop to exploit that power, but that's another issue).
Answer: True air speed (TAS) does indeed increase with altitude. The reason is because with increasing altitude the air density decreases. The Indicated air speed (IAS) which is measured by the pitot is a function of the dynamic pressure (Q) acting on the aircraft. The equation for the dynamic pressure is:
Q = 1/2 * rho * V^2
where:
Q = dynamic pressure.
rho = density.
V = True air speed.
According to the equation, if we want to keep the IAS or Q constant in a climb, the TAS should increase, because there is a decrease in density (rho) with altitude. So, there is absolutely nothing wrong with what you have learnt, because it is correct in the sense TAS increases with altitude.
So, why is your POH contradictory. Let us look at it, shall we? I will use the data given at 2000 ft and 12000 ft, under standard temperature to explain what is happening.

If we look at the table we can see that at 2000 ft, if you cruise at 2300 RPM, the engine is able to produce 66 Brake horsepower. The result is a TAS of 96 knots. But at 12000 ft the same engine is only able to produce 54 Brake horsepower at the same 2300 RPM. The reason why the TAS dropped to 92 knots is because your engine is unable to generate enough power at higher altitudes due to the reduced air density (C-152 has a normally aspirated engine). Hence, the aircraft is unable to fly at a higher TAS. If you want to increase your TAS you could increase the RPM to 2450 (more air rammed inside the cylinders) and get a TAS of 100 knots, but that will cost you more fuel.
It is expected that you will climb at the speed for best rate of climb (Vy). Once you reach your cruise altitude, you will push the nose down to level off, pull the power back to the desired RPM and trim it. If you climbed to 12000 ft and set 2300 RPM and trim the aircraft, the IAS that is shown in your air speed indicator will result in the tabled value of 92 knots. The value of IAS is not mentioned in cruise performance is because TAS is what determines your aircraft navigation performance and fuel consumption.
Comment: Flying at 12,000' at 2450 rpm will NOT cost you more fuel because 100 KTAS @ 5 GPH is better than flying at 2000' at 2300 rpm with only 96 KTAS @ 5.4 GPH.
Comment: I was comparing the power at 12000 ft. You burn more at 2450 than at 2300.
Comment: Let's remember that the performance chart are the result of extrapolation, interpolation and rounding, likely on a new airplane with a new engine. The climb charts show how rounding can give contradictory results. It generally takes longer to climb the next 1000 feet than the previous. But occasionally, like from 3000 to 4000, it takes less time than the previous 1000. Just because two entries both say "X" doesn't meant they are both EXACTLY the same. Also, the ride up to 12,000 in a flight school's 1980 152 near TBO is going to take a lot more than the 34 minutes and 3.4 gallons predicted.
Answer: Although, it is a backwards way of thinking about it, consider that the True AirSpeed is not changing with altitude for an aircraft keeping a constant speed. In actuality, the Indicated AirSpeed is what is changing. This is due to the IAS being measured by using Ram Air Pressure inside of the pitot tube. The RAP is directly related to the density of the air. The higher the air density, the higher the RAP at the same speed.
More gas molecule mass in the air is entering the pitot at any given time at lower density altitudes (higher air density). Think of it this way. A single bb would have less impact than 100 shot gun pellets fired at the same muzzle velocity.
Your pitot static system is actually measuring the impact of the air molecules and converting that into IAS. In order to fly at a constant IAS at a higher altitude, you have to increase your TAS because the air is less dense (fewer air molecules).
Comment: You have explained the difference between IAS and TAS, but you haven't explained why TAS is higher at high altitude
Comment: @MikeSowsun - Because TAS is not higher at higher altitudes. IAS is lower at higher altitudes for the same aircraft speed. But, IAS is measurable with the ASI. Whereas TAS is calculated. Also, IAS is more useful in determining aircraft performance (V speeds, etc). Unfortunately, that is the best way I can explain it. If I can up with something better, I will revisit this.
Comment: There is a free lunch. It is the reason airliners cruise at high altitude. The free lunch is LESS drag due to LESS air density which means more speed for the same fuel burn.  The gain in airspeed due to reduced drag magically makes up for less propeller inefficiency.
Answer: Inflight, the IAS is measured via the pitot/static system and is displayed on your ASI, the primary airspeed display instrument. TAS cannot be directly measured by a probe or transducer, it has to be calculated by using the IAS as a starting reference.
IAS: The pitot pressure is static pressure + the pressure on account of air molecules impinging on the pitot probe from the direction of flight. If the air density reduces, as it does with altitude, in order to fly a given IAS, it requires the airplane to fly faster through the thinner air for the pitot to experience the same pressure and indicate the same IAS. This faster speed is your TAS. Aerodynamic forces such as lift, drag, propeller torque/thrust etc. all depend on the flow of air molecules over the wings and body of the airplane and stall speeds, maneuvering speeds and limit speeds all relate therefore to the IAS.
TAS: is a calculated speed, as there is no instrumentation to physically measure it - in it's simplest form it is arrived at by plugging the IAS into a formula and based on the International Standard Atmosphere. TAS is useful for planning and actual navigation as it is your true speed in relation to the ground in nil winds.
Atmospheric Air Density as per ISA: As per the Standard atmosphere around 6600ft the density of air is about half of what it is at Mean Sea Level, at 12000ft around a quarter, and around 18000ft it is a tenth of the sea level density and so on.
You memorized "TAS increases as altitude increases" but the statement is incomplete in that it gives no info on the reference speed you are flying on your ASI. So a more complete statement is "IAS being constant, TAS increases as altitude increases".
POH 'Contradiction': Your C-152 POH Cruise Performance table seems to indicate a reducing TAS as altitude increases. This is because the page does not indicate the IAS to be flown, instead it gives you an RPM setting for level flight and the resultant TAS (and inflight we accept the resultant IAS). Take 2100rpm, the TAS is:
86KTAS at 2000ft
85KTAS at 4000ft
84KTAS at 6000ft
83KTAS at 8000ft
82KTAS at 10000ft
81KTAS at 12000ft
Seems to reduce with altitude, but calculating the IAS equivalent to the TAS and Alt at ISA using the 'aerotoolbox' webpage gives:
86KTAS at 2000ft = 83KIAS
85KTAS at 4000ft = 80KIAS
84KTAS at 6000ft = 77KIAS
83KTAS at 8000ft = 74KIAS
82KTAS at 10000ft = 71KIAS
81KTAS at 12000ft = 67KIAS

Here are values of TAS for fixed IAS, good for any airplane, and clearly showing the TAS increasing with altitude:
77KIAS
= 79KTAS at 2000ft
= 87KTAS at 8000ft
= 93KTAS at 12000ft

In the cockpit you can either fly a speed on the ASI (adjusting the RPM to suit) or you can fly the manufacturers recommended RPM and accept the resultant speed on the ASI.
As per the POH page, you input altitude and RPM (with mixture leaned) and the table gives you the Power, TAS, and Fuel consumption. The chart gives you this data for an airplane weight of 1670lbs and various RPM settings of the engine at even thousands of feet altitude ranging from 2,000 to 12,000 ft. (And for ISA, ISA-20degC, ISA+20degC.)
An input of altitude - RPM - OAT/ISAdev gives the TAS and fuel consumption per hour. These are the parameters you need alongwith forecast winds to make out a navigation and fuel flight plan. TAS and Wind gives Groundspeed/leg times and Heading to steer, and further with Fuel cons/hr it gives you the fuel for trip etc. The fact that the table outputs no IAS is of no particular disadvantage in the cockpit.
The data could have been shown by using a fixed IAS strategy, replacing the RPM settings with different IAS values in which case you would input altitude, IAS, Temp/dev the chart would output an RPM, TAS and Fuel consumption.
Comment: You have explained the difference between IAS and TAS,  but you haven't explained why TAS is higher at high altitude.
Comment: 1. That was already explained by other posts, but i should add it, you're right. 2.  The attempt was to explain why his POH shows lower TAS with higher altitudes which seems to contradict the fact of TAS increasing with altitude. I shall make the answer more explicit. @AlexK may comment if he's read my answer.
Answer: For a given power setting, True Airspeed increases with altitude because there is less drag due to the air being less dense. Aircraft are more efficient at high altitude because of this simple fact. Providing the engine can produce enough power, any aircraft will fly faster and further, without burning more fuel, if you fly at a higher altitude.
Your C-152 chart shows this quite clearly.
2000' 59% power = 91 KTAS @ 4.8 GPH
12,000' 59% power = 97 KTAS @ 4.8 GPH
Comment: The air is less dense so the propellor i less efficient and produces less thrust, the wing produces less lift etc.
Comment: So there is no "free lunch" here. Take that 150 into space where there is zero air resistance and connect the carb to an air cylinder so it still runs. The prop will turn but produce no thrust so TAS will be zero. At 2000' the prop is turning at 2200 RPM to produce the 91KTAS on 5.4GPH. At 12,000' the prop is turning at 2400 RPM to produce the 97KTAS on 5.4GPH. The engine isn't getting enough air to turn the prop any faster so the only reason the GPH is the same is the mixture is leaned out. Also, since the wing is less efficient with altitude, pitch must be increased so induced drag increases


Problems with chess anxiety?

Question: I've been dealing with this for a while and the game can just sometimes be overwhelming. I really don't know how to calm myself and it might be effecting my play. I've been told maybe its because I don't do enough physical exercise but I'm quite fit so I know its definitely a psychological/mental issue. Maybe its my ego that can't take losing? After all I did put quite a considerable amount of effort and time in this game so it hurts to lose against someone you know who hasn't done the same even if its only once out of lets say a hundred games. Chess I think is probably bad for my health, I honestly start to feel hatred or anger towards my opponent sometimes such as if they play it like blitz chess or something. Maybe Its about time I just quit chess all together, that option has really slowly grown more appealing to be honest. Has anyone experienced something like this?
Comment: This question might prove very difficult for the community to answer. It may be an idea to talk to a sports psychologist. One thing I do know though is that if you are too results-oriented while playing, it will affect your game negatively. Try to remember that everybody loses all the time, no matter how good they are. It's part of being human. If you play, try to play to have a good time, and try to stay as objective as possible regarding the position. Don't think about your opponent's dedication when you play. In the end it's completely irrelevant. Only the current position matters.
Comment: I used to be playing chess lots at chess clubs and wanting a rematch to make up for careless mistakes. I didn't like what chess was doing to my brain so I stopped altogether. Later, I went back once and this time, I worry only about thinking a tiny bit ahead. When I blundered my queen in one of those games, I didn't get a bad feeling because it was so much later than the time I stopped playing chess.
Comment: I don't know what can be done. I think that eventually, there's going to be a really good research technique that combines so many problems into one. Then you will probably get an answer to this question redirecting you to an expert in the right topic.
Answer: I really don't know how to calm myself and it might be effecting my play
Many people feel this way, e.g. becoming excited after winning material, or becoming upset when we slip from dynamic equality to a losing position.
To paraphrase IM Josh Waitzkin, who has a tutorial called The Psychology of Competition in the Chessmaster program:

Change your biochemistry to bring you back to the moment, e.g. take a break from the game, wash your face, or jog up a flight of stairs
Don't feel positively or negatively about previous positions. Stay objective and focus on just the position in front of you, rather than the preceding events. This is what a computer does

Chess I think is probably bad for my health
I'm not a doctor and I can't advise you on your health. If you feel that it is impacting your health, see your doctor. After all, your health is more important than playing chess.
Maybe its about time I just quit chess all together
Before you consider quitting chess, I would advise that you try a different, slower time control. I dislike blitz because I just don't have the time to play at the level that I would like to do.
Also, you may want to consider what it is that motivates you to play chess. Is it:

The competitive element?
The feeling of self improvement?
The artistry of the game?
Social engagement?
Something else?

If you don't feel motivated to play, then there is no need to force yourself into it.
Summary

What you feel is very common. Try to train yourself to remain objective when playing chess
If you feel the game is impacting your health, see a doctor
Reassess what you want from chess. If it isn't providing what you need, consider trying a different hobby
Answer: I can certainly feel your pain. I too have "chess anxiety", and performance anxiety ("stage fright") generally. For me, on some self-reflection, I saw that some of it came from an "inflated opinion" of my own ability, and there are possible hints of that in your "considerable amount of effort and time" comment too. In many ways it seems that "chess cannot be that hard", and yet it certainly is. If you can come to terms with these natural psychological-denial- and ego-type issues, it could help. For example, can you envision the next time you drop a piece (and it will happen sometimes right?) just laughing it off as "silly me" and playing on? Your opponent may just as easily drop a piece (later) too -- in a way non-master chess is much like the blind beating the blind with their canes.
One time in frustration I played some don't-matter online games with the goal of losing. And was amazed at how many mates my opponents were missing. That was an eye-opener.
Another problem for me with gameplay was the clock vs. my perfectionism. I got much better results, and more satisfaction even when losing, by re-orienting toward faster-but-good/sufficient/reasonable moves over my usual best-move obsession. (One problem with the latter for me was it often blinded me to the fact that I was under an attack and needed a good defensive move rather than an offensive one. I.e. situational blindness.)
Hope some of this helps. Good luck and enjoy the game.
P.S. I agree with the suggestion to investigate "sports psychology", even though I haven't myself. Even if only reading a book on it...

Problems with chess anxiety?


In video editing, how to fade scenes out, with next starting immediately after?

Question: So this is my first using the video editor so I'm not really sure how to do this. With my animation, I want to add an effect where 1 scene would start to fade out and the one after it would start immediately after the first starts fading. I thought the cross effect would work but it justs makes the first one start fading and the second just stays frozen until its time to start. I would move the stripes around to test it but I have this synced with music so there's not much there I can do.
Comment: Is the desired effect to have a scene fade out to black, then fade from black into a new scene or are you wanting a scene fade out to reveal a different one? Please add images of your current strips on the VSE to understand what you want to do.
Answer: How-to
To acheive this effect, use the Gamma Cross Effect Strip.

To begin overlap your videos, so it looks like this(it does not matter which channel the videos are on).
Next, select which video you want to fade out with the RMB(usually the first video). Then, using SHIFT RMB select the next video.
Finally press SHIFT A and navigate to Effect Strips... and click on Gamma Cross. The cross duration should be the length of the overlapping videos. You cannot change the length of the gamma cross directly, you must increase or decrease how much the videos overlap.

Reasoning
If the videos are directly next to each other, but not overlapping, you can't have the second video start right away because how can the second video start if the first video is still going and they are not overlapping?

Reference : https://www.blender.org/manual/editors/sequencer/strips/types/effects/cross.html
Reference Video: https://www.youtube.com/watch?v=T_PRXTZoHtI&list=PLjyuVPBuorqIhlqZtoIvnAVQ3x18sNev4&index=14
Audio Reference Video: https://www.youtube.com/watch?v=beWj_mw0M-I
AudioAs for the audio do as RobinsSea suggested in his answer, insert keyframes along the timeline concerning the audio level of the videos. To do this select the audio track and navigate to the properties panel "N". Make sure your timeline is where you want the audio to begin fading out! Over in the properties panel go to the volume area and hover your mouse over the volume. Then press "i" to insert keyframe. Do the same to complete the fade out, just set the volume to 0 and the timeline where you wish to end.
Happy Blendering!
Comment: Could you also show the fading of the volume out and in? I think that your answer is very valid, however it seems to be lacking the audio part of the question :)
Answer: I have found you can do a video cross-fade using keyframes together with opacity settings for two overlapping video clips... I tend to use a black colour as base. This technique is a wee bit quicker than (although perhaps not quite as visible or flexible as) Gamma-Cross. You would do the audio cross-fade the same way, inserting a keyframe and setting volume at 1.0 where you want the fade to begin, go to the end of the clip and set volume to 0.0 and insert a keyframe there. In the second clip, start volume at 0.0 (set keyframe), then go to the end of the first clip and set volume of the second clip to 1.0 (set another keyframe). Hope this all makes sense.


Is there an algorithm to help figure out how many machines should host a website?

Question: Something that might incorporate desired average response time and average request rate as a factor?
Comment: No, there isn't.
Answer: I wouldn't say there is an algorithm, at least that I know of since it would be too complicated.
The amount of servers you need is a wide range and depends on what your website does, how much traffic it gets, how important your site is and how much reliability you need.
Small low size sites with no server side code can handle very large amounts of traffic and your likely to run out of bandwidth before the server is overwhelmed.
If your site is very complex, large number of processing items and other or requires 100% up time you many need many servers.
Answer: Jeff is right, the number of variables here is too large to pin this down.  If you run a web service that converts video to MP3 the CPU is going to be gone really fast.  If you run a site that streams video or music, the bandwidth will saturate.  Then you have what language did you write it in, how good were your coders.....
Answer: Sure - and it will be different for every website and all its components : the hardware of the servers (assuming they're all identical of course), the speed of all the network links (external and internal, if it's DB-heavy.)
So, for your code, you could ramp-up activity from one to lots against a single server with something like LoadRunner and get a graph of request rate (simultaneous users) and response times. Make an equation from that data that fits the line or curve.
Now add a second server and do the exact same testing. See if the equation is the same. Now double the user count and see if the graph continues on the same equation, or if it's different.
Continue doing this and you have your algorithm. However, at some point, you will stop being able to add web servers to improve response times. You have found a bottleneck that isn't your number of webservers. Determine what that is and fix it.
Aha - now you have changed another variable besides number of requests. Re-do all your work. Also re-do all your work every time you change the code, or add indexes to your DB, or improve your hardware, or even put more cache in your SAN (for example.)
Also - for users, keep in mind that there are different types of activity - think of Amazon. Do some users just browse a lot, do some users spend a lot of time in reviews or in the message boards, do some load up shopping carts and then checkout? You have to measure the type of user activity from your production system, to make classes of users to use in your testing, in ratios that hopefully mimic what the production load looks like.
Answer: Such modeling systems exist, but they are expensive.  Take a look at  Hyperformix and Opnet as solution sets for your question.   One thing to keep in mind is that all models contain some degree to assumptions and at some point in the future you will need to run an actual performance test of your model/proposed model to see if those assumptions are correct and that the system scales as predicted.   More often than not the actual performance test results in new information which is used to update the model to make it a better predictor of actual application performance.


What are applications of Coin Change problem?

Question: I've read so many about the Coin Change problem, debates about wheather it is solvable using Greedy, Dynamic Programming and so on.
Nevertheless I cannot find an application of this problem.
What are applications of Coin Change problem?
Answer: This is going to sound very silly but, I once had to implement the coin change solution for the purpose of... distributing change!
The application was a soda pop vending machine that could accept bills and coins and dispense coins.
The spec required the use of a least coin pay, plus an alternative algorithm should one of the coin tubes be empty and thus unable to dispense coins of that denomination.
The classic example was buying a 60 cent soda pop with a dollar (I know, pop was cheap back then ;-). This leaves 40 cents change, or in the US, 1 quarter, 1 dime, and 1 nickel for least coin pay. If the nickel tube were empty though, the machine would dispense 4 dimes.
I know to is not quite the lofty heights of academia, but it was an actual application of the problem's solution. On a further note, more modern coin changer mechanisms implement their own coin management so for those more capable peripherals, we would just let the coin mech figure out if change could be made.
If not, the customer would get the dreaded NO CHANGE error message and the money would be returned.
Answer: Coin change problem is actually a very good example to illustrate the difference between greedy strategy and dynamic programming. For example, this problem with certain inputs can be solved using greedy algorithm and with certain inputs cannot be solved (optimally) using the greedy algorithm. However, dynamic programming version can solve all cases.
A simple example can be as follows. Let's say that you have N tons stuff, to be delivered from one place to another place. You can use airplane (capacity 100 tons), big truck (capacity 15 tons), medium truck (capacity 10 tons), etc. How do you manage to send your N tons of stuff with the minimum number of facilities?
There are an infinite number of applications that you can find.


How to minimize scope creep?

Question: Scope creep can easily transform a good project into a distressed one.  What are the methods for minimizing continuous expansion of project requirements?
Comment: @Drew that's perfectly fine.
Comment: Is it just me, or did you answer your own question?
Answer: I've been dealing a lot with a scope creep over the last 2 years. I created a list of things that is a must to keep in mind in order to minimize the negative impact on the project.
At first - you should realize that scope creep will happen!
You should:

know the requirements;
know the client's expectations;
have balls to say "No". Saying "Yes" to placate the customer can cause a sufficient scope creep. As a result - a good project might become a distressed project;
always question the necessity for the change. Make sure that there is a decent justification for a change. Define change control process in advance;
determine how the scope change will affect the schedule, cost and resources. See whether some of the milestone dates can or can't be shifted;
get user involvement early. A good idea might be to make customer research interviews before having an actual product;
know who has "signature authority". You should manage closely this kind of stakeholders;
avoid gold plating and perfectionism. Change your mindset from making everything "perfect" to "just enough";
be aware of penalty clauses for late delivery. By pushing through scope changes that will elongate the schedule, the PM could avoid penalty clauses.
Answer: Focus on customer value.
Just because the client thinks of a new function doesn't mean the one you are writing right now has lost its value.
I try to follow these guidelines:
- Slow down. Do not jump to the new scopy things. The original scope was analysed and considered carefully. The new scope probably just popped up. No way all the requirements and implications are known. Give the idea time to mature. While you work at the original scope.
- Once you're out of 'jump-at-it' mode, capture the new scope in requirements, userstories, etcetera.
- Check how it fits in and if your original scope already provides part of this new scope.  And while you are at it; ask for a businesscase for the new scope. How is the client going to earn the money back?
Many ideas fail this stage as they are already possible, or are not really close enough to the hearth to actually write down the specs.
For ideas that survive, I still like to get the program running in Operation first. Check out 'minimal viable product'.
When your program is in actual operation, you will have meaningful discussions: Do we add on the things we thought of originally (original scope)? Or would you rather have us build that new idea first?
Which idea adds the most value at this point?
When you do this right, the word 'scope creep' looses its meaning.
Answer: The best way to minimize scope creep is careful planning and a structured change management process. By having a clear project plan and schedule and not letting change uncontrolled from the very beginning, is the best way to avoid scope creep. You can make adjustments to the project plan, but you'll have to assess how it will affect your budget, schedule and scope. A must in every project is also to document the scope in a scope statement, this document will help you justify your measures to your client and serves as proof at the end of the project that you have fulfilled the requirements in the contract.
Answer: Firstly, you shouldn't try to minimize expanding requirements.  Change will occur and should occur and there should be no pressure to inhibit that.  What is needed is a change control process, one that can process change both prospectively and retroactively, the latter being used only minimally.  Therefore, when requirements change or new ones are identified, you process the change quickly, incorporate the new scope into the project, get time and money, and keep working.
Change is good.  It makes the product for the customer more valuable and, in the case for sellers, increases revenue.
Answer: In terms of acceptance criteria for change requests, the process needs to facilitate shared accountability and customer focus. For example:

The general wisdom for avoiding scope creep goes something like this:

Require the scope change requester to complete a form, or otherwise formally describe the change.
Log the form (like you do everything else).
Determine the impact of the requested change.
Review the change with the client / business owner / project team, and approve or reject the request.
Update project documents and notify the team of any changes.

My trick is to basically move step 3 up as a component of step 1, and include a short questionnaire about the impact of the suggested change right there on the initial request form. I also ask for the change to be mapped — quantifiably, if possible — to one of the key metrics / business goals laid out in the project's business requirements.

References

Fight Scope Creep with this Change Request trick
Answer: IMHO,
Possible causes of scope creep and their indicators
Loosely defined projects - If the project is not properly defined along with its success, the team will not have anything to make their stand on.
Possible Indicators:
You keep getting references to other apps/sites - I feel that in most cases, "idea" is overrated. The majority of new-entrepreneurs are simply trying to create someone else's success. They will not have defined vision in their own head regarding what they are trying to achieve as a result they will always be diverging away from a track that they set out to achieve in the first place.
You get complained at - A LOT - They are just trying to re-create someone else's success and they will always find their achievement behind their expectations without actually knowing what they are trying to solve. They are just sensing an opportunity without properly defining the problem and success.
Possible solution - Have a good customer facing unit (does not necessarily have to a separate entity but a group that can include people working in different capacity). Agile encourages changes and discourages contracts but that does not mean you are obiliged to give someone a full-fledged machine learning-Financial health-assessment tool when they initially set out to achieve a financial log book. It will be the unit's responsibility to keep client focused and the goal should always be to have a defined projects. You may need good negotiations and organizational skills for this to achieve. However, if you have already made the mistake of not defining the project, try to correct it in whatever capacity you can as of now. In most cases trying to define the project after it has been developed over a significant period will be incapable of producing desired effects and it will probably be for the best for both parties to seek oppurtunities elsewhere.
Solution does not work for the problem - A lot of project managers sometimes rely heavily on the client for requirement. When someone comes in with a project idea they are presumably trying to fix a certain problem. There needs to be a requirement analysis and proper vision regarding how the team will approach the solution. It is unfair on the client's part for a team to expect solutions from the client and clearly this never comes good. It's like going to a doctor and the patient advising how he should approach the treatment.
Broadly speaking say for eg. I want to build a software for my cafe. The problem is subjective and the statement has multiple meanings.
I could be trying to fix the problem with my employees and their payroll management OR
I could be trying to build a software that helps me optimize my inventory management OR
I could be trying to build a software that helps my customers place their orders online.
So the solutions, design and user experience will vary on what I am actually trying to achieve. How the results will be presented in a meaningful way could be completely different for any of the set mentioned above. So the requirement analysis has to be approached subjectively and conclusions properly defined to create a vision/directives that the team will follow. Obviously this goes without saying that it should be participative in nature, considering the most important aspects of keeping stakeholders happy and working team motivated.
Possible indicators:
You keep revisiting the same feature - Client knows that the solution does not work for the problem and keeps coming back with solution that they think might work but it actually does not.
A sort of a change-cycle repeats with every sprint - Client could unknowingly be trying to align you back to the solution that actually works for them.
Possible solution - Chances are, the client knows what his problem is and he knows the solution you provided does not address his or her core problem. They will try to come up with a solution which again may or may not work. To put things into perspective, say I am trying to track my finances, then I would probably want data visualisations with KPI's, the client may not even know what KPI is. As a solutions provider, it is upto us to actually propose ideas that can actually solve their problem. After all this is what innovation is all about. The team should at all times remain motivated to achieve success which needs to be defined. If the team understands the problem and if their solutions are aligned then both scope creep and scope change will not be expensive.
Properly define project and it's success. This is the most important thing, regardless of your organisation's philosophical bend, the organisation must have unified and unequivocal process of actually defining project and it's success criteria.

How to minimize scope creep?


The phenomenon of Négatité

Question: I am a novice to JP Sartre's philosophy of existentialism and I came across the notion that in Being and Nothingness,The Origin of Negation where he claims that "nothingness is at the origin of negation".
I do however have difficulty understanding this notion.  I understand that négatité, being a phenomenon, brought into being only by being-for-itself, can only happen because of the unbound freedom we possess, and that our existence precedes our essence.  Is this why nothingness is at the origin of negation?
Any help would be appreciated.
Comment: The claim - very debatable, if Sartre's point of view on philosophical discourse is not fully adopted - is that *negation* is not defined only as "lack of" some "positive" quality or fact. Negation is "real": it is grounded into *nothingness* that in turn has ontological status.
Comment: You can see the comment into Sebastian Gardner, [Sartre's Being and Nothingness : A Reader's Guide](https://books.google.it/books?id=klrUAwAAQBAJ&pg=PA65) (2009), page 65.
Comment: Pierre's absence is an instance of what Sartre calls a *négatité*, a 'negated' - a 'negativised' state of affairs, incorporating and constituted by negation. Négatités presuppose expectations and other human orientations but, once again, are transcendent objects of positional consciousness - not experiences but what certain experiences are of; Pierre's absence is 'a real event concerning this café', 'an objective fact'. 1/2
Comment: The concept of *nothingness* (Ie *néant*), in distinction from *negation* (*négation*), now enters, as referring to the ontological kind
and status of that which constitutes the negativity of *négatités*:
nothingness is a 'component of the real' or 'the structure
of the real'. 2/2
Comment: We can easily find some relevant linguistic examples. Consider the statement : "I have not eaten even an apple today". It is fully "negative", but it is hard to find its "positive" counterpart. At the same time, we grasp its meaning quite easily. But, from this linguistic fact, to conclude with a full-blown ontology...
Comment: @MauroALLEGRANZA I still don't understand why nothingness would be the origin of negation.  Could you elaborate a bit more?
Comment: @MauroALLEGRANZA Page 65 is blocked from view for me, could you briefly describe what it says?
Answer: Nothing(ness) definitionally is being not Being. It therefore not is, ontologically. It is just that "not", the refusal to be this or that concrete X. Sartre often characterizes for-itself and its activity (choosing, i.e. running from a fact towards a possibility) as "being by mode of non-being".
Nothingness should not be understood as something which is absent here still potentially is present somewhere else (real or imaginary - no matter). Nothing is what is nowhere. Or, rather, it is here as the pure negation/attenuation of any state of identity in "i is X"; that bold "is" is what gets negated. Nothingness emerge (due to human Consciousness making choices) as holes bored through on the body of Being, to attenuate self-identity of things.
Because, for a thing (phenomenon) to have any sense/meaning it must be weakened in its sameness with what it is - for the sake of tying with some chosen possibility. For example, a red ball appears meaningfully "red" to us because its redness is being rejected in exchange of some potentiality in the red quality of the ball. Venus de Milo "has no arms" to us meaningfully only because it could have arms, i.e. be what it is not; however, that "could have arms" is firstly not another state or being, it is the possibility which exists by mode of nothing because it does not change the Venus de Milo to another identity, it just attenuates its present identity by loosening. Only due to that attenuation (negation) of the statue's being without arms it can appear meaningfully as having no arms.
There is nothing (no anything) that separates the Venus as it appears from its identity of Venus armless, yet it is not equal to it. Simultaneously, there is that same nothing that separates it from the possibility of armness, yet having arms is not any guaranteed, even not under consideration. (Nothingness does separates by no miles or millimeters, and it does link by no bridges or molecules.)
Consciousness opens things as phenomena (appearances). That is, it acts as negation and brings nothingness to things. It attenuates a thing's being what it is, due to which the thing can appear what it is. To appear means to be X with potentialities, while being is just to be X - the state of closed and dense identity where no meaning could arise and even the statement "i is X" can't linger as intelligible. Sartre's concept of Nothing/Negation is sharply dialectic, it owes to Hegel.
Comment: May I also speak of this negative in another context, the context of Hegel? The cold, hard finite, the IS, we may think of as positive Being. This Being (the status quo) is confining, even suffocating. The negative step is the step to freedom!  It negates the present IS, smashes it, transcends it, frees the possibilities contained in the status quo. The swing of Hegels logic: First: Being, then Nothing (the space for freedom).
Comment: I mentioned earlier two good answers on Sartre by ttnphns, and of course this is one of them!  I neglected earlier to upvote both of them because my mind was in the air, so I corrected that tonight and upvoted both answers.
Comment: Hegel: even nature frees itself and realizes its possibilities through a series of negations.  "The bud disappears and the blossom breaks through, and we may say that the former is refuted (negated) by the latter..."
Comment: Thank you for your comments. Your second one demonstrates even sartrian Being accurately, to me.
Answer:
[why is that] nothingness is at the origin of negation

According to the IEP

The power of negation is an intrinsic feature of the intentionality of consciousness... in... this power of negation... I operate a nihilation of that which is given... Sartre says that 'the name (...) [of]
  this possibility which every human being has to secrete a nothingness
  which isolates it (...) is freedom' (BN, 24-25).

So yes, the answer of why it can occur is "freedom".
Obviously, this answer is quite short.
Comment: My comment was no more than a comment. I wasn't in disagreement. I just wanted to say that nothingness/negation are tied with freedom, as you correctly pointed out, still, I don't think it is didactically effective to _explain_ their origin from freedom since freedom is a wider term.
Comment: I would only object that it is freedom which is possible through the "mechanics" of nothingness/negation, rather then vice versa. Othervise we have first to define and explain what is "freedom" (for Sartre). Without relying on nothingness/negation concepts it would be quite difficult to do. More, the freedom is a wider concept because it includes also spontaneous self-projection, or choice.
Comment: @ttnphns would that depend on the definition of 'why' in the question? i'm not sure, i only answered through google (as you may see), so am more that willing to bow to your greater knowledge

The phenomenon of Négatité


How to Peel Potatoes

Question: Whenever I have to peel potatoes, I spend much of the time fighting the slippery, just-washed potatoes and keeping them from shooting out of my hands...what's a good way to peel potatoes more efficiently/easily?
Comment: Without scraping your knuckles ;--)
Comment: Check out this: http://cooking.stackexchange.com/questions/6137/fruit-peeling-techniques/6146#6146
Answer: I noticed the term "just washed" in the question.
My suggestion is -- don't wash them before peeling.  Wash them after peeling.
Water is what makes them slippery -- if anything, dirt adds traction as you're peeling.
(and I tend to do one end, then the length of it, slowly rotating, then the other end ... no idea if that's faster or less slippery ... but for carrots, I always do the fatter end first, as I find it'd harder hold a peeled skinny side while peeling the fatter end)
Comment: This is fine for potatoes that come more or less clean. For potatoes that come with soil clinging to them, the idea of the blade against the soil sets my teeth on edge (and will probably blunt the peeler quickly too).
Comment: Good advice.  If you plan to peel them at all, then there's really no sense in washing them with the peel still on.  And washing with the peel *off* helps get rid of any loose bits of peel you may have missed.
Answer: I know this might sound crazy, but is your potato peeler old or dull?  Sometimes a nice new peeler does the trick. Also, I'll sometimes hold the potato with a paper towel if it's slipping in my hands.
Answer: This may sound like a silly answer, but it actually isn't: just do it faster. I've worked in professional kitchens, a lot of the time on prep shifts, and although there are lots of great tricks for prepping vegetables, the single thing that helps the most is to simply concentrate and move your hands faster. Build up your speed slowly so you don't cut yourself. And of course be sure you have a very sharp peeler. But mainly, work on slowly increasing your tempo until your hands are a veritable blur, and it won't seem like such a chore anymore.
Comment: Or you could just put them into a potato peeling machine and it's done in a fraction of a second. pop, vhvhhvhvhhh, done
Answer: If the potatoes really are shooting out of your hands, you might try something as simple as loosening your grip. When I peel potatoes, I don't even squeeze with the hand in which I'm holding it. Generally, putting a lot of pressure on anything when working with knives or other sharp implements can be risky.
Answer: A different idea, don't peel them at all.  I can't think of a dish where I wouldn't rather have the earthy, crispy, chewy skin of a potato.  Just run them under water and lightly brush the dirt off, cut out any eyes, and be on your way.  This is somewhat of a non-answer, but it's how I approach most tedious cooking tasks.
Comment: I also prefer leaving the skin on, and generally prepare them exactly how you described.
Answer: You might have good luck with holding the potato similar to how a football is held for a field goal kicker - place one end on the table and hold the other end with the fingers of your left hand (if you're right handed), essentially sitting the potato vertically, and peel down from top to bottom.  You'll still have to pick it up to get the ends, but you should be able to get 90% of the potato done this way.  To keep the potato from slipping off the counter, rest it on a paper towel.
Mary Ann from Gilligan's Island presents and even easier method in this video.  Basically, you score the potato all the way around, put it in boiling water   for 15 minutes, then drop it into an ice bath...and the skin will just come off.  Very cool!  Of course, you'll want to reserve this method for potatoes that are going to be mashed or otherwise need to be softened for one reason or another.
If you don't mind buying a device specifically for this there are some pretty cool potato peelers on the market, but it might not be very cost effective unless you eat a lot of potatoes!
Answer: Also, you can hold the potato with a towel, or if you have one, one of those "jar openers" that is just the round silicon grip improver.  Those work great!

How to Peel Potatoes


Having four sites to jump between is ridiculous

Question: We need a trilogy site where each of the four sites in the trilogy is in a tab.
Comment: What's a trilogy tab?
Comment: They are linked at the bottom, which is silly. It means hitting the "End" key to find the link and switch.
Comment: I sympathize with the viewpoint...it has gotten complex to work out which question goes where, and it is a (mild) nuisance having to switch between the various sites.  One option would be links to the sister sites on each page - top, bottom or at the side (under or near the ads and stats)
Comment: Open each site in a browser tag?
Comment: One site to rule them all... and in the darkness bind them?
Comment: When I go to Google News, I see all the news. But I can go to "sports" or "business" or "weather" if I like and see only those stories. That's like what I want from the trilogy. I could see all the recent things going on, or I could filter down to one category.
Comment: Try 26 sites, then ;-P. (Of course, we have got stackexchange.com itself, now, which helps.)
Answer: Why not make your own mashup site? You might just make some money off of it!
Another option is consolidating most of your interests to RSS feeds on something like Google Reader. That is what I do.
Comment: That's a good idea.
Comment: [Already done it](http://220.127.116.11/joshuakehn/codebase/homestead/). :)
Answer: Answered on the blog:
https://blog.stackoverflow.com/2009/07/why-cant-you-have-just-one-site/
Comment: When the bad guys are wrecking havoc in your town, do you call the Justice League or do you call an individual superhero, and he refers you to another one because it's a border-case of whether he's the right hero to handle it?
Answer: Maybe Yahoo Pipes could help with this. You can input multiple feeds, filter and re-read it afterwards. I'm at least going to try that.
I still think that the most annoying thing of following all three web-sites is checking up on your answers. Just the feature of your profile on one site would list your responses and status on all the other linked accounts would work wonders for me.
I mean, the accounts are already linked, why not provide a common notification platform for all sites?
Answer: This is the sort of thing I'd hoped would get accomplished by a desktop app, but we're still lacking an API for that.
Answer: This has been asked numerous times and there has already been a couple posts already about using a Greasemonkey script to allow you to add in some of the information at the top of the site where your current rep information is.
Comment: But that's not a solution, that's a workaround.
Comment: Thor K.H most people don't believe there needs to be a work-around. I am on the fence on the issue. Sure it would be nice to be able to have a central location to have all my SO-family related information in one space, but I also am quite adept at using bookmarks (and Greasemonkey) so that it doesn't bother me.
Answer: If only he added another site that could combine all of them in aggregate...what I really would like is just a way to not have more hurdles in order to log in (I already have an openid login, I'm on Serverfault, but someone decided my question belonged on SuperUser, so then I had to track down the password to get into the beta site, then find the question after logging into that one...
I think it would be nice to navigate the sites more transparently so that there is less resistance and less hassle. There are questions that are related enough that they border between topics found on SU and SF, for example. As a sysadmin I have to deal with user issues. Sometimes those issues could be found by home users or sysadmins in labs and workplaces, so then you're going to have duplicates and it's harder to move from site to site to find what you want...
It seems as if the whole team has this picture in their head of some kind of self-organizing emergent wiki, which would be great, but just so long as the users aren't getting agitated because they have to triple log in to find an answer (as I just got directed from SF to SU but had to go to meta then back to SU and go through logging in and associating my profile to do...AGH!)
The team will do what they want in the end and that's fine and dandy. I love the sites. I'm just wishing there was an easy way to have them accept my login as a portal and easily slide among the sites and content with a filtering system of some sort, like "make serverfault my primary portal" as the default and the others with their own themes show visually where I am and I can aggregate information without keeping track of what I'm logged into and have to log out of each time.
Comment: Yeah, right now meta and stackoverflow and superuser are remembering me, but somehow I got logged off from serverfault (went too long between visits?) and I haven't bothered to log in for a week to see if I have any more responses over there. Logging in is just enough of a hassle that if I don't know if anything's waiting for me there I won't do it.
Comment: Or like forgetting that I put this up a week ago and just thought of logging in here to find if anything's changed?

It would be nice to aggregate replies in one place, like making the user profile-centric and not site-centric! I don't mind various statistics kept separately in rep and whatnot, but jumping site to site drives me batty.
Answer: Use iGoogle. Create a tab for each site. Within each tab:

subscribe to the Newest questions feed
subscribe Most Popular
subscribe to your favorite tags. (i.e. python, c++, ms-access, whathaveyou.)
Answer: They don't need a trilogy site to combine the other four sites; they just need one site, period (which they have, called Stack Overflow), and have people tag things appropriately. Separating things into different domains, creating duplicate user accounts with different reputation levels and potentially different logins, and fragmenting the community needlessly was a bad idea. Don't focus on making workarounds to the real problem; they should just consolidate it all back into SO.
Comment: Completely disagree.
Comment: Completely disagree with your disagreement.