What are Good Resources for Baker's Percentage Ranges?

Question: I would like to try to apply the baker percentage concept to create my own baked good recipes (cakes, cookies, muffins, etc.).  However, I can't seem to find any resources that indicate appropriate ranges for each type of recipe.  I have found many resources that explain the baker percentage concept, but none that provide appropriate ranges.  What are some good resources that explain baker percentages for various baked goods?
Answer: You are confusing terms here. Baker's percentages are used for bread and bread only. In pastry baking, ratio is even more important as in bread, but traditionally, nobody calles it "baker's percentages".
The book you want is Ruhlman's Ratio. It gives exactly the information you want for pastry and some other things (noodles, mayonnaise). About the only common ratio he doesn't explain is ice cream. It also has some recipes, but the main focus is on the exact proportions of flour, sugar, fat and liquid you need for each type of baked good.
Comment: Perfect! This is exactly what I was looking for and you explained why I couldn't find it. Thank you.
Comment: Might be a worthwhile review to look at about Ratio: http://www.amazon.com/review/R1XD6BACB02CVE/ref=cm_cr_pr_perm?ie=UTF8&ASIN=1416566112
Answer: Peter Reinhart's The Bread Baker's Apprentice gives baker's percentages for all its recipes.
In addition, if you have a source that gives weights, you can calculate the percentages yourself: flour is always 100%. Each other ingredient is divided by flour weight (then multiply by 100). So, if you have 500g flour, 325g water, that's 325÷500×100=65%. Alternatively, Artisan Bread Baking has a baker's ratio calcultor that'll do the math for you.
King Arthur Flour, Cooks Illustrated, give bread recipes by weight, so you can do the conversion.
Comment: I learned about the concept in BBA. Reinhart throughly explains the ranges for bread. I am trying to find ranges for items like cakes, cookies, muffins, etc.  I was hoping to find a reference that provides ranges of percentages of each ingredient for the items listed above.


What wrong did Satan do?

Question: Satan did not prostrate to hz Adam because he thought fire was superior to mud and someone made from fire should not prostrate before someone who is made from mud. Is this why Satan was expelled or was it was simply because he did not do what Allah said?
Comment: I think the answer of this question http://islam.stackexchange.com/q/34817/13438  also answer yours.
Comment: http://islam.stackexchange.com/questions/2023/what-is-wrong-with-the-devil?rq=1 see this
Answer: Iblees was expelled for disobedience [He refused, and was arrogant so he became of the Kafereen]

When We told the angels to prostrate before Adam, they all obeyed except Iblis (Satan) who abstained out of pride and so he became one of those who deny the truth. [2:34]
Answer: We need to look closer to what happened , first Satan disobeyed God but Adam also did the difference lies in what after , Adam returned to ask for God mercy, But Satan because if its discriminatory thinking and its jalousie did not do what Adam did even though Ibliss(Satan) was one of the most worshipping creatures before Adam's creation , The main lesson that we can extract is that if you want to gain the Paradise worship God and ask for his mercy and forgiveness , also discrimination and arrogance are so dangerous.

What wrong did Satan do?


Power structure of French vs. German federalism

Question: While Germany is a federation of states, France has chosen to devolve some of the power to its regional governments. How has this affected the development of these countries? Has one system fared better than the other?
Answer: The two states of affair are a result of history, so I'm not sure your question can be answered as is.
On the French side, the historical process has been to centralize ever more power in Paris. Initially it was about growing the royal domain and keeping French vassals in check. Power concentration in Paris continued for all practical intents and purposes all the way to 1982. Put another way, all French roads have been leading to Paris until recently, and it's not that big a stretch to suggest that decisions to develop areas outside of Ile-de-France were being taken in Paris.
On the German side, in contrast, the Holy Roman Empire was a hodgepodge of semi-independent states operating under an elected emperor that had little practical authority on its subjects' realms. Besides the rise of Prussia, two key events that led to modern Germany are Napoleon I dismantling the HRE and reorganizing it as a confederation with a much smaller number of larger states, and Bismarck managing to unite the latter states against Napoleon III who he tricked into attacking Germany. Put another way, the future Federal states of Germany have historically enjoyed a very large degree of autonomy throughout their history. It should be no surprise, then, that Germany has no city that concentrates the bulk of its economic activity and economic decision making.
Which of the two is hard to say. But I'd surmise there's little correlation between how the country's administration is organized and how its industry fares. There are many other important factors that kick in, such as the presence of transport networks (rivers, roads, rail) or that of raw materials, education and work ethics of the workforce, capital availability, the presence of business clusters, and so forth. Intuitively, each of these are a whole lot more important.
Superficially you could put forward that a lot of economic activity self-organizes across Germany, whereas it takes an impulse from Paris to try to create, say, a tech cluster in a region like Bretagne. But economic activity in Germany actually is concentrated in a few areas, and it is in these places only that things self-organize. Berlin is to Brandenburg, in this sense, what Paris is to France. Or put another way, the dynamics of centralization vs decentralization and its impact on the economy merely exists, I think, at a different level in Germany than it does in France.
Comment: @Nikhil: Per the beginning of the sentence you're quoting, I'm surmising it and honestly have no idea how much research there has been on the topic or what the economists' consensus on the topic is. I would point out, however, that there are examples of both with fairly strong economies (the US, China) and with fairly weak economies (Spain, Greece).
Comment: Thanks for the enlightening historical perspective. Can you please cite: "there's little correlation between how the country's administration is organized and how its industry fares."?
Answer: How has this affected the development of these countries? Has one system fared better than the other?
This is reflected in a variety of ways. Each has areas where they excel although one would be hard pressed to find a consensus over which was better overall, and there has been convergence of the systems, especially in the post-WWII era.
Economic Development
Historically, the industrial revolution in France was led more heavily by the state and big business than in Germany where private firms and small businesses played a larger role, although both countries had a more state led industrialization path than England.
In Germany, a lot of local infrastructure development (e.g. opera houses) was developed on a competitive basis with different states seeing each other as rivals, while French infrastructure development has tended to involve more "master planning."
Health Care
The French health care system is run by a national bureaucracy. The German health care system, like Obamacare, involves a mandatory health insurance system where health care is administered primarily by private insurance companies. Both have their virtues, but they reflect different levels of comfort with centralization.
Higher Education
As another example, the German university system was heavily tilted towards STEM programs for private industry,  In contrast, the most prestigious university in France is the Ecole national d'administration which trains senior civil servants.
Administrative Law
Political scientists often speak of the French Civil Service as a separate branch of government from the politically appointed executive branch officials of the French Presidency and Prime Minister's office. The French Council of State (which runs the administrative law system and sets top level regulatory policies) is widely viewed as the best run administrative law system in the world. It is also from France that we get the word "Bureaucracy" before their centralization developed modern style bureaucracy earlier than any other country in the world.
But, it was also not politically responsive to have to contact the French equivalent of your Congressman if your neighborhood street light goes out. French governmental provision of services has tended towards the technocratic, while German governmental provision of services has been more political.
Public Sector Unions
The differences between the centralization of the systems has also likely contributed to the pattern of public union action.
France has a long history of national, public sector union strikes that are effective because the centralization of the system makes the entire nation a natural bargaining unit for them.
In contrast, in any federal system, including Germany's, the fact that one state's public sector workers are engaged in labor action does not affect other states. In much the same way, as this answer is written, all of the teachers in West Virginia have been on strike for several days shutting down all public schools in that state, but other U.S. states have barely noticed.
Different Kinds Of Federalism
Federal systems, however, differ a great deal from each other. Germany and Canada, for example, centralize more kinds of legislation (while still decentralizing administration of those laws) than the United States, which in turn, centralizes more kinds of legislation than Switzerland.
As a result, federal states like Germany, with a high level of centralized legislation have not had the same regulatory race to the bottom that has characterized federal countries like the United States, where legislative authority is more decentralized.
Comment: Someone correct me if I'm wrong, but I believe that the central two differences between the United States and Switzerland is the U.S. lacks a national direct democracy component (all 50 states have some form of Direct Democracy) and the United States centralizes immigration where as the Swiss leave that up to the Cantons (US State equivalent) to decide.
Comment: @hszmv A Swiss canton is about the size of a large U.S. county. Some states in the West of the U.S. like California and Colorado have lots of direct democracy, others have very little. The Swiss decentralize much more than immigration allowing more cantonal differences than the U.S. does (the U.S. decentralizes less than it naively appears from the constitution).
Comment: @ohwileke:  I meant Cantons were the equivalent to States in the level of a Federal Government.  I'm not saying all U.S. States offer lots of direct democracy.  Just that they all give some level of it.  As for the U.S. Decentralization, I'm not arguing that Congress is not great at abusing what power it can get and we did have that Civil war which was a turning point in Centralized power.


Why do I feel small stings all over my body in stress?

Question: I've realized I'm expierencing stress (or rather embarassment) quite differently than I used to. Like a year ago (I was 16) I expierenced stress just as a short warming up of my shoulders. For the last year or so, I expierence it more like a lot of very small stings seemingly randomly appearing everywhere all over my body. Is there a name for this condition?
Comment: Sorry, nevermind, I think I have already found what it is - so called shooting pains: http://www.anxietycentre.com/anxiety/symptoms/shooting-pains-anxiety.shtml
Answer: Paresthesia Anxiety Symptoms -- seems like the term/condition you are looking for (though I am not a doctor and am not diagnosing you as such -- I'm just trying to inform you of the term you might be looking for).
In this Wikipedia entry on Paresthesia, it describes the sensation as such:

Paresthesia is an abnormal sensation such as tingling, tickling,
  pricking, numbness or burning of a person's skin with no apparent
  physical cause. The manifestation of a paresthesia may be transient or
  chronic.

It doesn't use the word "stinging" as you do so I'm not sure if this fits the bill, but it does go on to describe how it can be quite sporadic and painful. Other articles also have used the word "stinging" in reference to Parethesia.
This CalmClinic article "4 Ways to Prevent Pins and Needles From Anxiety", does a pretty good job of correlating how stress and anxiety are strongly linked to Parethesia (the stinging, tingling, burning, pins-and-needles sensation). I'm not sure if your stress leads to anxiety and sometimes panic attacks that include hyperventilation, but if so, here is an explanation as to why:

During hyperventilation, the body has too much oxygen and not enough
  carbon dioxide. That imbalance causes every vessel inside the body to
  constrict, while simultaneously reducing the release of calcium into
  the nerves. Both of these cause the nerves to feel "tingly."
Those with
  anxiety are also prone to hyperventilating more as a result of their
  hyperventilation. Hyperventilation can cause symptoms of not getting
  enough air (shortness of breath) which makes people breathe in deeper.
  But that deeper breathing is actually counterproductive, since too
  much oxygen is the cause of hyperventilation. This makes the symptoms
  get worse, and increases the likelihood of tingling.
Hyperventilation
  is one of the main causes of panic attack and severe anxiety symptoms,
  and the pins and needles feeling is undoubtedly one of the most
  troublesome for those unaware of their breathing patterns. Not
  everyone experiences the same sensation either. Some people feel pain,
  while others feel a tickling. Some people may experience different
  sensations at different times.

BUT do keep in mind that there are other reasons for this sensation to develop, even different stress and anxiety reasons (if you're not necessarily hyperventilating):

Other Links Between Anxiety and Pins and Needles Those with anxiety and those that suffer from anxiety attacks are also more prone
  to body consciousness. They become over-sensitive to every sensation
  their body makes, and unintentionally overthink the causes of those
  experiences.Feet, arms, fingers, and legs, all may fall asleep due to
  pressure on the nerves. For a person without anxiety, this experience
  is rarely given a second thought. To a person with anxiety, this
  experience can cause a significant amount of distress – enough to make
  someone worry about their health.In addition, dehydration and other
  less serious diseases may also create a tingling feeling in the limbs
  as well as anxiety. If you have an anxiety disorder, you may be more
  likely to react very strongly to these sensations until you experience
  an anxiety attack.

Hope this helps, but please do consult a doctor.
Comment: http://neurology.health-cares.net/paresthesia.php: This also includes the stinging pain and might also provide some other insights...
Answer: I have a similar experience right now and correlate it to a different challenge. Because if there is one thing I am not, it is being anxious.
I've experienced muscle weakness over de last 4 months which I've now recently realized has been correlated to a lack of vitamin D in my body.
With having had a vitamin D boost from the pharmacy, my health is getting a lot better now and exercising my muscles makes sense again (because they actually grow again).
What I notice is I still have these stings sometimes, even in locations which did not have the most serious muscle weakness. But what I expect is that with enough exercise and eating the right healthy foods, the stings will also go away.
Do you exercise?
Comment: Welcome to Health.SE. Since health is an important topic, the site has a strict policy that **all answers** should be [backed up with reliable references](https://health.meta.stackexchange.com/questions/1/should-we-require-references-to-back-up-all-answers) in order to provide the community with the means to assess the merit of the answer, regardless of the reader's background. *See [this list of reliable sources](https://health.meta.stackexchange.com/questions/112/what-are-reliable-sources)*. If you still have trouble with this, feel free to visit the [help].
Comment: Because you had a problem that "was correlated" to Vit D deficiency, that bears no real relation between your muscle weakness and his prickling sensations. Please emend and corroborate your answer to be relevant, or it stands in danger of deletion.
Comment: I do and I used to take vitamin D as well (prescribed by a neurologist) but then my nutritional therapist told me not to (apart from the fact that it had been prescribed to me together with calcium even though both medications stated you shouldn't take them together with the other one :) Thank you very much, I had exercised less last days due to my business and I've been experiencing more stings, both when I excercised and when I got embarrassed.


Higgs boson and quasiparticles

Question: Do we know exactly the difference between particles and quasiparticles? Is Higgs boson a particle or a quasiparticle? I ask this because if I understood well, Higgs boson created by a spontaneaous breaking symmetry and correspond to a Goldstone mode. Maybe I am wrong in my explication.
Comment: Related: http://physics.stackexchange.com/q/21954/2451
Comment: This is a definite possibility, and the general field is called "technicolor". People don't say "quasiparticle" in this case, but "Goldstone boson", or "pseudo-Nambu-Goldstone boson". The idea generally is implemented by making the Higgs mechanism the pion condensate of a QCD like theory that confines at the Higgs scale.
Answer: A quasiparticle is an elementary collective nonlocal excitation of a quantum medium (such as a crystal); examples are phonons (describing sound waves) or Cooper pairs (describing superconductivity). In contrast, a particle is (in the context of high energy physics) the elementary excitation of a local quantum field; examples are the electron or the photon.
In the standard model, the Higgs is modelled as a local field, hence is a particle, but there are alternative scenarios, where the Higgs is not built into the theory as a field but emerges as a collective excitation and hence is a quasipartice. To distinguish between these scenarios requires experimental input that doesn't yet exist.
Answer: A quasiparticle is a particle-like entity with definite internal structure and size. Quantization rules make such structures more "real" and more strongly conserved than than similar classical constructs would be.
In semiconductors, the entity known as a hole is a good example of a quasiparticle. It behaves very much like a particle carrying positive charge, although in reality it's just an absence of an electron. Holes unavoidably involved many particles to exist, including the atoms of the semiconductor lattice and its electrons.
A notable feature of a quasiparticle is that since it is constructed out of more fundamental particles, they always have definite and non-zero sizes in space. They can never be modeled as true points, as can for example an electron.
The Higgs boson in contrast is proposed to be a fundamental particle that does not require any other particles to exist. It thus is very definitely not a quasiparticle, but is instead a fundamental particle in the same "no visible internal structure" sense of a photon or electron.
The reason all of this can get a bit confusing is that because quasiparticles reflect fundamental quantization and conservation laws, they are in many cases subject to many of the same mechanisms seen for more fundamental particles. That's why you see Nambu–Goldstone bosons invoked in both fundamental physics and in solid state physics. It is a reflection of the generality of the Nambu–Goldstone mechanism, rather than an assertion about the presence or absence of lower-level structure in the particles that are involved.
Pair creation is another example of a rule that applies across both fundamental particles and quasiparticles.
Pair creation is the mechanism by which a sufficiently energetic gamma ray can be converted into a free-space electron and a free-space positron. That process exists fully within fundamental physics, since the gamma photon, electron, and positron all show no evidence of deeper structure at available energy levels.
However, a curiously parallel pair creation process also occurs at much lower energy levels when a photon strikes the right kind of semiconductor lattice. That lower-energy photon also creates a pair of charged quasiparticles and creates. One is a conduction electron, which within a semiconductor involves the local atomic lattice through which so it moves. It is thus best modeled as a quasiparticle that has both structure and size, one that happens to include an electron to give it charge. The other quasiparticle is a hole, which similarly involves the lattice and has no fundamental particle at all behind its version of positive charge.
Similarly, the Nambu–Goldstone mechanism can apply both all-fundamental particle sets, or to all-quasiparticle (or mixed) particle sets.

Higgs boson and quasiparticles


Control Panel shortcuts in ExpressionEngine 3

Question: In EE2, I could click the (+) icon in the top menu to add a shortcut button to the current page. These could be managed in my "Main Menu Manager" in my profile. This was really handy, but I cannot find a similar feature in EE3. Does such a feature exist out of the box, or are there any add-ons available to do this?
Answer: It seems they moved this feature to be in a drop down menu rather than directly in the main UI.  I loved adding links to the top of the old EE, made things quick.  But now they are in the top right corner under your username dropdown.  When you click on your username you'll see a "new link" option, along with any other links you've already added.
You can also manage your links under "My profile->quick links".  With "my profile also under the username drop down in the top right.
Hope that helps.
Comment: I totally agree, makes them less "quick" if you have to hunt them down in a menu. You could probably jump over to the EE forums and throw that in a feature request.
Comment: AHA! Thanks, Chris. I should've been able to find that. Kinda stinks that you can't add links to the visible menus, and that these handy shortcuts are hidden in a dropdown.
Comment: I believe dorothy Dorothy's answer below (using the Menu Manger) is also worth looking at - it allows you to add a row of buttons across the top of the CP and assign them to user groups, which is extremely helpful. No add-on needed!
Answer: You can add short cuts into the control panel using the Menu Manager.

Go to Settings (button in top right hand corner)
Choose "Menu Manager" from the left hand navigation (under General Settings)
Click on "Add Menu Item"
Choose "Single Link"
Give the link a name
Enter the relative path to the addon e.g. cp/addons/settings/freeform
Save
Save Menu Set

I'm not sure how to use the addon dropdown option.  Let me know if you work it out.  I hope that this helps.

And here are the docs from EllisLab
https://docs.expressionengine.com/latest/cp/settings/menu/index.html
Answer: Another thing you may want to look at is Addon Menu. It helps a little. Still similar to clicking your name if you just want Addon Links, but it essentially does it for you.   ;)
https://github.com/amphibian/addon_menu.ee_addon


What are the Pros/Cons of investing in the Bitcoin ETF vs. bitcoins yourself?

Question: Hypothetically, the Winklevoss ETF is approved tomorrow, 3/10/17. The ETF price, which starts at $100/share, will correlate directly with the price of Bitcoin, I assume. What would be some pros/cons of investing in the ETF instead of buying bitcoins myself and storing them in my own wallet? The ETF would be easier to buy/sell than using an exchange plus I wouldn't have to worry about the security of my coins.
Answer: When you say "I won't have to worry about the security of my coins"... I think you've got this backward.
There's nothing more secure than a paper wallet that has been generated offline. Bitcoin was created as a way to avoid the need to trust a third party. If you don't believe that's necessary, then you're just trading it hoping to make USDs, not because you believe in it's intrinsic value.
in other words,
Are you speculating on the price, short term, hoping to make USD?
Get the ETF.
Are you skeptical of the global financial system, and want to hold money outside the reach of any government?
Hold bitcoin.
Comment: the etf won't immediately start trading if it's approved. The effect of the approval on bitcoin's price will have already played out.
Comment: I am skeptical of the global financial system but short term, I am speculating the price. When I say I don't have to worry about the security of my coins I am referring to my personal management of the coins. I do not have to worry about managing them myself although entrusting third-parties is contradictory to the motive of decentralized currency.

Basically, you're saying is I am just speculating short term price I should buy into the ETF (assuming it's approved) instead of bitcoins ?
Answer: <code>           ETF                                     BTC
Fees       expense ratio, trading, and commission  transaction fee
Taxes      IRA/401K protection                     post-tax, and capital gains?
Liquidity  broker hours                            seller/buyer demand
Minimums   one share                               one satoshi + tx fee
</code>
Another way I would compare the two is by thinking of BTC as buying a house,
and ETF as being a member of a condominium. With your home, you control ownership. For a condo you don't get ownership of the real land. In each case, the trade-offs
can be related to its level of risk.
Owning a home is direct personal cost.
You bear the burden, repairs, acts of nature, are your responsibility. Also,
you are making slower, single purchases. With this responsibility, you get control.
In contrast with condos, there
are multiple interests. Part of the attraction is freedom from upkeep, and
there is a sense of security from other partners, shared risk. I know of
members that have multiple properties. It's this shared exposure that makes it so you can hold more quantity. At the same time, there are plenty of challenges with decision by committee, and HOA dues.


Can't boot Windows 7 after installing Ubuntu

Question: I installed Ubuntu yesterday alongside Windows 7 and whenever I start my computer I don't have the option to boot Windows. When the computer starts it goes straight to Ubuntu without giving me an OS selection menu. When it goes to Ubuntu it gives me Ubuntu repair options and Ubuntu normal start option. I still have all of the Windows 7 files on my hard drive, but Windows 7 has no way to boot.
Comment: It just happened to me after installing Lubuntu 14.04 LTS alongside Win7, however after running the software updater in Lubuntu the GRUB OS selector came back. Might be worth a try before you go re-installing everything.
Answer: Run fdisk -l on terminal to check the windows partition.
If you found it, then type update-grub
Then reboot
And you will able be able to choose your selected OS
If permission is denied on running fdisk -l alone, add administrator privileges by entering you password after writing this code into terminal sudo fdisk -l
Comment: Nice! This worked for me, using Ubuntu 16.04 and Windows 7. I had three partitions: 1 for Windows 7, 1 for Ubuntu, and 1 for Ubuntu swap. I installed Windows 7 first on `sda/1`, then installed Ubuntu on `sda/2` (and `sda/3` for the swap). I booted into Ubuntu, ran `fdisk -l` from the terminal: Windows was shown as an NTFS partition. I then ran `sudo update-grub`, and the output showed **Found Windows 7 (loader) on `/dev/sda1`**. I then restarted my computer and Windows 7 showed up in the boot list! Thanks for this answer Muhammad :)
Comment: Worked also for me! I installed Ubuntu 16.04 LTS and I had Win7 installed. Now I can see both options in boot menu. Thank you!
Answer: I had the same problem! After starting the computer the GRUB Boot loader displayed UBUNTU and 2 further entries but not Windows.
After long trying I succeeded by performing the following steps:

Find out on what hard disk and what partition WINDOWS is installed.
This you can do after opening a terminal and type at the prompt
sudo fdisk -l

(this must be done with administative rights, so you will be ask for your password).
You will now get a table of your partitions with device names like
 /dev/sda1, /dev/sda2 ..  and so on.

If you have installed windows it might have type NTFS. This means if the second entry in this table is like this:
Device...Boot.....Start...End......Blocks......Size .........Id.....System
/dev/sda1..*...2048..467118879..467116032..222,8G   ..7.....Linux
/dev/sda2 ..467118080...961144831....494026552..235,6G  7.....HPFS/NTFS/exFAT
/dev/sda3 ..1270138878...1953523711..341692417..7,6G        5.....Extended
/dev/sda5 ..1270138880...1945182207..337521664..7,6G        83....Linux

windows is installed on the second partition of the first hard disk (sda2)
(In my case both operating systems were installed on one hard disk with 2 partitions, on the first I had installed UBUNTU and Windows 7 on the second. )
Press C  for accessing the GRUB command prompt.
At the Grub-Prompt enter the following 3 commands:
Grub>   set root=(hd0,2)
Grub>   chainloader +1
Grub>   boot

Notice: In the command set root = (hd0,2)  after hd type the (zero-based) number of the hard    disk (here 0 ) and after the Comma the Number of the partion (here 2) . If your windows partition is sdb1 you must type set root=(hd1,1) if it is sdb4 type set root=(hd1,4) etc…
Now Windows should boot!
Now you might want to have Windows 7 permanently as a menu item in the GRUB Boatloader menu. This you can get as follows:
menuentry 'Windows 7' {
   set root=(hd0,2)
   chainloader +1
   boot
}

Save the file and close it.
Open a terminal and type on the command prompt:
sudo update-grub

After restarting my computer I got a further entry with windows 7 in the GRUB menu, so I can chose between Ubuntu and Windows.
Comment: where should i save the menuentry?
Comment: I'm getting "bootmgr is missing" is this fixable? I do not have the windows CD (read that it would be required to fix). Is there a way to fix this any other way?
Answer:
First, restart your PC or laptop.
After restarting you see the Grub menu. Select Advanced Options for Ubuntu (with the arrow keys; press Enter to confirm).

In the Advanced Options menu you will see an entry Recovery Menu that you need to select.
Carefully select the grub – Update grub boot loader option.

It will automatically add an entry for Windows 7/8/10 to the boot menu.
To restart, press Ctrl+Alt+Del.
The system will restart and you finally have a option to select Windows 10/8/7. Select Windows and finally you have with your Windows OS.
Comment: I tried it thousand ways and this solution only worked.
Answer: First thing first, you need to repair your WIn7 bootloader, and you can visit this page to learn how to do this. Write down on a piece of paper the required commands for fixing both boot and mbr. You'll be using those codes after getting to the Command Prompt screen.
Next you can download Boot Repair iso image as suggested in the previous answer by 'user3005324'. Choose 64 bit iso image if you have installed Ubuntu 64 bit or choose 32 bit iso image if you have Ubuntu 32 bit. I hope Win7 is the same architecture with Ubuntu, I mean you have either Win7 32 bit and Ubuntu 32 bit, or you have Win7 64 bit and Ubuntu 64 bit.
Burn the iso image, and restart your computer with the new Boot Repair CD in tray. You can write Boot Repair iso image on a USB pendrive with Unetbootin tool if you don't have a regular CD to use. Read instructions on how to use Unetbootin in Linux/Ubuntu, they are located at the middle of this page: http://unetbootin.sourceforge.net/ .
After Boot Repair cd or usb pendrive finish loading, you can press the 'Recommended Repair' option, wait to finish and after you get the message 'success' you can reboot and use Win7 and Ubuntu which will be present both in your start-up boot menu.
Comment: Though it might work, you might want to have a quick look at the solutions below, which might solve your problem more easily (start by updating grub)
Answer: 1> boot into ubuntu live cd and do a simple os-prober in terminal
2> does it show win7?
If yes, you are safe.
Just  follow this link https://help.ubuntu.com/community/Boot-Repair
if not, you are probably screwed.Probable reason to that is windows was installed in LEGACY BIOS and u installed ubuntu in UEFI BIOS (provided your computer supports this new bios version) which means u have to reinstall everything.
But if your computer doesn't support UEFI bios, and both operatng systems are installed  in legacy bios, then the above link should work.
Answer:
Restart your PC.
Choose  "Advanced options for Ubuntu".
Choose recovery mode
Update "grub"
It will automatically load the other operating systems in the boot menu.

Precondition : you should have installed Ubuntu with "install Ubuntu along side with other operating system" option at the time of installation.


Why is Esperanto popular in Iran?

Question: Is there a reason why Esperanto is a lot more popular in Iran, compared to some countries like Arab countries in the Middle East and North Africa?
Answer: Apparently it was promoted after the Iranian revolution in 1979:

Ayatollah Khomeini of Iran called on Muslims to learn Esperanto and praised its use as a medium for better understanding among peoples of different religious backgrounds. After he suggested that Esperanto replace English as an international lingua franca, it began to be used in the seminaries of Qom. An Esperanto translation of the Qur'an was published by the state shortly thereafter. In 1981, its usage became less popular when it became apparent that followers of the Bahá'í Faith were interested in it.

(https://en.wikipedia.org/wiki/Esperanto#Islam)
Comment: It is quite ironic, however, that it was praised for better understanding *among peoples of different religious backgrounds*, and then is dropped when that actually happens...!
Answer: What if Iran's proposal to the League of Nations in 1922 that everybody teach Esperanto in schools had been passed?
Comment: Hello Oliver. your answer to this question is not correct. because you miss first Revolution of Iran (Persian Constitutional Revolution). also you miss Pahlavi period actually they were interested about Esperanto.
Comment: This should really be a separate question; Stackoverflow is not the place for longer discussions, but just for questions and their answers.

Why is Esperanto popular in Iran?


Lugging vs stalling an engine

Question: Does stalling an engine count as lugging it? I know lugging is not good for the engine for various reasons. Does stalling do those to the engine as well?
Thanks
Answer: Think of stalling an engine as lugging it once. While not good for your engine/car, it won't do the same damage which is possible with lugging your engine. Stalling the engine is basically the engine not having the torque to overcome the demand which has been put on it.
As far as lugging damage, check this answer. Lugging an engine can cause real damage.
Comment: How come it lugging once? Since it the fuel is not getting fired at all?        On my bike my rear wheel locked up during braking. And the clutch wasnt pulled in. Does that count as lugging it also? Thanks for your answers
Comment: Stalling is lugging it once because the engine fires just the once at the time of the stall then dies. This might/might not equate on a single cylinder 4-stroke engine. With your bike, you stalled it.
Comment: Okay i understood the first part thanks :) for the second part, it didnt kill the engine though. Just some noises.thanks
Answer: Running at low revs "lugging" is not really damaging provided you have appropriate oil pressure, but I'd question the mileage gained by it, modern ECU's will provide appropriate fuel and may run richer trying to raise these speed when you're trying to accelerate from an already high gear.  Modern engines are far more tolerant than engines of decades past and are not likely to suffer any internal damage.
The only real concern I would have would be additional wear and tear on items such as engine mounts, transmission mounts and your clutch if you're driving a manual car if you are unable to keep the car from bucking at such a low rev.
Stalling isn't really as bad as people would have you believe IMO, more of an inconvenience or embarrassment.  Teaching many people to drive manual transmissions over the years I've never had a stall induced breakdown.
Comment: The damage that lugging does comes from the fuel burning at the wrong time, so it tries to bend the crankshaft rather than turning it. This bad news for the piston since it is facing resistince from the both side. And it is even worse for the cran and connecting rods. And running richer will make it even worse since all those components will get that "wrong" type of force.
Comment: Agree with @Erunanethiel about lugging doing damage. It ***can*** cause damage, not only the piston, rods, crank, drive train, but can break piston rings if you do it enough. Its like taking a jackhammer the the entire works, or in car parlance like putting an impact wrench on it ... a *really big* impact wrench.
Comment: @Erunanethiel I think you're confusing lugging with detonation which is regulated by timing.
Answer: On my bike, with the clutch out I have locked the rear brakes, though the engine didnt stall. Is this lugging it?

Lugging vs stalling an engine


When deciding who to marry, how do you communicate with your potential spouse while remaining within the norm of Islam?

Question: I know that there are certain norms in Islam that has to be followed while meeting people of the other sex. Now in situation when you are to decide whom to marry, how do you go on discussing this issue with the opposite sex so that the meeting remain within the norm of Islam?
Answer: Different muslim cultures have different rules ('urf) for how separated men and women are to be. Shaykh Hamza Yusuf has commented that he has friends in western Saudi where the wife eats with them and they all know each other, and he has friends from eastern Saudi that he's known for 20 years, and has never met their wife. Different strokes.
Still, a male and female are not to be alone together. If by dating you mean old style courting, where the male and female speak politely with a chaperone, this would be allowed by many opinions (but not all! I recall reading in The Reliance of the Traveller that a woman is not to talk to a non-mahram, even to reply to his salaams).
A common thing (or so I've heard) that they do (in Egypt specifically) is when the prospective couple meet (with a chaperone) and decide to take the next step, they do nikah. Islamically, they are now legally married, but for their (cultural) purposes they are just engaged, and they start "dating." In this case, dating would of course be halal, since they're technically married. Then later they have the walima (marriage reception), which they (culturally) consider to be the actual marriage and that's when the wife will actually move in with the husband.
Or so I've heard! And God knows best.
Comment: Heavens, marriage seems to be more of a social obligation than of a religious one. Really, I have no clue on this subject.
Answer: Hmmm a nice question and a nice and suitable background!
Well according to Islam, a man is not allowed to meet a woman in person. But when it is the matter of their marriage such as you are describing. Like they are engaged or are to be engaged to  each other and want to know more about each other.
Then it is allowed for them to talk and know each other. But to keep in mind, they should stay in the limits! They should just know each other such as their nature, their likes dislikes!
And should give their acception or rejection in answer!
However, dating is not allowed! What you might wanted to ask was the meeting of the man and woman, who are to married and want to know more about each other.
There is nothing bad or evil, in a meeting of man and woman. But the purpose should be positive and there shouldn't be any sin involved. Their families should know! A girl before leaving her house should inform her parents and so on. It should not be kept hidden!
Comment: Suitable references, anything... I know what you want to mean; but this is a place where society, norms, cultures muddle up, make a hodgepodge of the things.So, any reliable Hadith something like this http://islam.stackexchange.com/questions/391/marriage-proposal-to-a-girl?rq=1


a way to inform user about a failed paste operation

Question: In my application if the user tries to press CTRL + V to paste something with nothing really in the clipboard .I wish to inform the user about the same meaning a informative message saying that Clipboard empty.I dont want to display nasty and ugly dialog box,instead something sort of a feedback tip which will just display and then fade off.But apart from that,is there anyother idea?
Comment: On Windows and OS X, if you don't have anything on the clipboard, Ctrl-V does nothing and the Paste option is disabled in menus. I agree that this isn't providing feedback as to why the operation failed, but I think that it's common enough that it probably doesn't confuse many people.
Comment: What are you dissatisfied about with your suggested solution?
Comment: @Bobwise Generally speaking people use the shortcut keys while working,very less people will go to edit->Cut (more clicks and more effort) say for example you are writing a big email everytime you have to do cut , in that most people will not prefer going and clicking.
Comment: @edeverett feedback tip might be good solution but then atleast in my application i want to use it for "telling the user about what action she/he has performed" and not for failed actions
Answer: Firstly, consider if feedback is genuinely necessary. The pattern of paste action > nothing happens is so common across so many systems that people are used to it.
However, if you really need to provide feedback, use your suggested solution. Modal dialogs are inappropriate here as they interrupt the workflow for something that is not critical and doesn't prevent the user continuing. Your idea of a feedback tip is good. Take a look at SE's own tooltips and go with something similar. When the feedback is about an 'action the user has performed', use a neutral or success color such as yellow or green (again, SE has a good yellowy-beige for this). When the feedback is an error, such as in this case, use a red background. You may also want to scroll the page to the message, but be careful of this. Scrolling for non-essential messages again disrupts user workflow, so for something like this I recommend popping the message then leaving it.
As for positioning, again take a lead from SE. Position the message above the input field with a small arrow pointing down to the field. That way it's mear the location of the error so is easy for the user to see but doesn't obscure the user's viewport.
Answer: I think that the best way to show non important errors is using a toast. Toast are non intrusive with user actions, shows a small message and fades in a short time.
Comment: I agree, though don't feel 'pasting empty content' warrants any feedback.
Comment: @IAmJulainAcosta i could not agree more with you :)
Answer: The fact that nothing happens when a user hits CTRL+V with an empty clipboard or invalid data is the feedback.
Adding a message won't provide the user with any additional information that they can act on and thus is unnecessary.
Comment: @17of26 I agree.  There's a good flowchart by Google on when to show and not show acknowledgement/notification to user. The principles in this Google article applies in my opinion. In this particular scenario, notification/acknowledgement is not needed in my opinion.  Reference: http://developer.android.com/design/patterns/confirming-acknowledging.html
Comment: I don't think that this is a correct option, because it leaves the user without a feedback of what is actually happening. The error can be that nothing is on clipboard, that the system is unresponsive, and a lot of possible options, that leaving the user without proper feedback are frustrating.

Is related with this question: http://ux.stackexchange.com/questions/11660/why-do-people-clear-the-screen-multiple-times-when-using-a-calculator
Comment: If the system is unresponsive then they're not going to get a message either!
Comment: A CTRL+V paste can only fail in two scenarios that an application would be capable of reporting on:  1) Empty clipboard 2) Non-pasteable data.  In both cases, the resolution is the same - go copy something.  Giving the user an error message doesn't really help them here.
Answer: I would simply trigger the systems default "beep" sound. In Java it is triggered like this, if you want to know what I mean:
<code>Toolkit.getDefaultToolkit().beep();
</code>
Answer: Apart from that the user surely will notice that nothing actually was pasted, the system warning sound could be helpful. Please don't use the error sound, since this isn't a system error - but a warning sound would enforce the feedback to the user, along with your fading message of an empty clipboard.
Comment: I wanted more of a visual display,say for example clipboard is not empty but it has invalid data in that case sound will not help.I agree about fading message but the point is ,what is best place to show it so that it is not obtrusive to the user and yet he is informed about that
Comment: @user52179 How would the system know that the clipboard has invalid data?
Comment: That is something my application is going to take care of
Comment: @user52179 'invalid data' is a very different thing than 'empty paste'. One is data validation, the other is user interaction. If you're asking about invalid data, that really has nothing to do with cutting and pasting. I can type invalid data as easily as paste it.
Answer: I'd start by considering what is the normal interaction here. 'Normal' isn't always 'best' but it's a good place to start especially for a feature that is ubiquitous across nearly all software and all operating systems.
In most cases, pasting empty content does nothing else in terms of alerting the user. I'd stick with that barring any other arguments as to why your app would need to behave differently.


How to make a .xib show up in a custom class

Question: I was wondering how to connect my custom class and my .xib. In Interface Builder I have changed the class of the Files Owner to my custom class. I then created an IBOutlet and connected it to the view of the .xib. I then added an instance of my custom class to my UIViewController. My custom class is a subclass of UIView, so I set the background of it to black and can see it appear on top of my UIViewController. What I can't see is my .xib???? Here is my code for my custom class... (FreeThrow is my custom class... FetView is my .xib)
<code>@interface FreeThrow : UIView {
IBOutlet UIView *mySquareView;
}
@property(nonatomic, retain)IBOutlet UIView *mySquareView;
-(void)createMe;
@end

@implementation FreeThrow
@synthesize mySquareView;
-(void)createMe {
[self addSubview:mySquareView];
[self setBackgroundColor:[UIColor blackColor]]; // I did this to know my UIViewController is showing this class... which it is
}
@end
</code>
Here is my code for what I call from my UIViewController...
<code>freeThrowView = [[FreeThrow alloc] init];
[freeThrowView createMe];
freeThrowView.frame = CGRectMake(8, 42, 335, 230);
[self addSubview:freeThrowView];
</code>
What code do I need to add? What do I need to do? What is the problem? Why is my .xib not showing up.
Answer: Sadly apple doesn't give us a way to truly link a xib to a view via IB alone. You'll have to do it via instantiation. Here are some past answers to similar questions:
How do I associate a nib (.xib) file with a UIView?
Loading .xibs into a UIView


Is it possible to configure Apple's Magic Mouse to be recognised on start up?

Question: This question may apply more roundly to all bluetooth mice but in my case I am dealing with an Apple Magic Mouse. I have followed the set up instructions here; https://wiki.ubuntu.com/Multitouch/AppleMagicMouse
closely. I have even removed the mouse and started from scratch more than once repeating each step described carefully.
Every time the computer is started it does not see the Magic Mouse by default. I need to keep a wired mouse connected to the computer at all times which I use to log in with then connect the Magic Mouse, in a somewhat counter-intuitive exercise! Any help would be greatly appreciated.
The following is an edit made to include responses to points made by others in response to my original question;
I believe I do use GDM as my understanding is it is default in Ubuntu 10.10. The only edit to the boot process I have made is this; http://www.omgubuntu.co.uk/2010/12/new-smooth-intelligent-plymouth-boot-screen-for-ubuntu/ I'm no expert, I think perhaps plymouth loads after gnome display manager? This plymouth theme is the only edit I've made to the boot process so although I'm not 100 percent certain as to what gnome display manager is, my login process is default apart from that. Would gdm affect this issue, eg, should I ensure I do use it or replace it with something else?
My Magic Mouse is second hand, so I have no way of knowing if it is paired to another computer. It quite possibly is but would be either impossible or at least very difficult for me to track down that computer. Does the magic mouse have its own memory and can this affect its ability to connect to my computer?
Thank you again.
Answer: For me this setup works quite well.
Some things you might want to check:

Do you use the gnome display manager?
Have you deconnected the mouse from all other computers it's has ever been paired with? My mouse connected automatically to my friends MacBook until I discovered that it was still paired to it.


Pca on multidimensional data

Question: My data has stock returns over n periods for x stocks and m factor exposures for each stock ( ex: value, momentum) for n periods(output of regressions ) . Can I club this data together and then compute the correlation matrix (x by x matrix) and then run pca
Do I need to standardize each data set separately ( returns and factor exposure)?
Answer: It is matter of choice of model

do you believe that the volatility of each of your stock / factors is stationary?
what is, according to you, the needed number of observation to compute the coef of your covariance matrix with accuracy?

For instance, results on rough volatility suggest that if you want to use you volatility estimate over the next $N$ days, you should use the last $N$ days to estimate it. It is probably a lower number of days than the ones you want to estimate your covariance...
Moreover, for the covariance: do you really want to use days spanning from 6 months before the financial crisis (say early 2008) to one year later (says 2010)? This (relatively short) period is made of very different covariance regime...
Choose your model, can be one different scale for each stock / factor, hence you reduce the returns to their "innovation", and after that you compute the covariance of what you have. If you want more formalized details, I suggest you have a look at Practical Volatility and Correlation Modeling for Financial Market Risk Management, by Torben G. Andersen, Tim Bollerslev, Peter F. Christoffersen, and Francis X. Diebold.
Answer: When running PCA on the correlation matrix, you do not need to standardize the data. Correlation is the same as covariance of the standardized data. You may also want to experiment with other types of factor analysis since model
$$
R = F\beta + \varepsilon,
$$
where idiosyncratic risks $\varepsilon$ are unexplained by any factors, makes more sense. For example, you can try maximum likelihood factor analysis or principal axis factoring. Stata and SPSS are quite convenient for this purpose. R has it as well, of course.

Pca on multidimensional data


When did Guy join the satanic cult?

Question: When did Guy begin to take part in the plan to use Rosemary to give birth to the devil's son? It's weird because at the beginning of the movie he didn't want to buy the department.
Answer: The exact reason reason why he joined the cult isn't shown in the movie.
Guy forms a bond with the Castevets after he and Rosemary go to their apartment for dinner.
Shortly after Guy lands a role in a play when the actor who was originally cast suddenly and inexplicably goes blind.
It can be implied that the cult made the actor go blind through rituals. Another example of this happens when Hutch goes into a coma later on in the film after Rosemary goes to him for help.
Therefore I think the most likely reason is that he was seduced by promises of fame and success from the Castevets and this is why he joined them.
We don't know precisely when he joined but it was some time after the first dinner with the Castevets and when he got that first role. So it was fairly early in the film and before the sex scene with the devil.
Comment: Whoops..I don't know why I read "When" as "Why" :/
Comment: No matter, I thought the same.
Answer: He is talked into it after the first dinner with Roman and Minnie. While Rosemary is in the kitchen washing dishes with Minnie, Roman and Guy smoke and talk unseen in the living room/parlor. When Rosemary joins them they are close together and go silent, with Guy wearing an expression of secrecy and deep anxiety. And great INTEREST for if you remember he makes a point to say Roman was not boring him but he was very interested in what he had to say and could they get together again to talk about it?
I believe this secret conversation between Roman and Guy is where the idea is introduced to him, with Roman having picked up on his "price" so to speak in that he would do anything, even betray his wife in an unspeakable manner, to become rich and famous. In fact he is shown as such a narcissistic self consumed character that he doesn't even help with the murder of hutch and does not go to his funeral.
I think the deal is actually sealed once Guy is shown that it was real on that the actor who got the role he wanted goes blind. Once he is shown that they are the real and not just two crazy old looks delusionally talking about black magic, and that when he did what they told him he is in all the way.
He's what's referred to as a succubus. I know that most would not agree with me, but of all the characters in this movie, it's Guy that is the most evil. He betrayed his wife, allowing her to be raped by Satan, drugged by satanists, suffer in excruciating pain and also had a hand in murdering someone who was supposed to be his friend, all for fame and money, greed and narcissism. The satanists at least believed they were serving a higher purpose and hurt strangers and people they had no ties to. For me, the character of Guy is far more diabolical and truly evil. Zero integrity.
Answer: There are several scenes before Rosemary's impregnation that allude to Guy's reasons to join the cult. When him and Rosemary are being showed the apartment, the landlord asks Guy if he is a doctor. He lies, saying yes, when in reality he is a struggling actor. He was Luther and played a small role in Nobody Loves an Albatross This means that he's a liar, and a mediocre one at that. His role as an Albatross also echos his impending betrayal (albatross' represent burdens and obstacles).
It is clear throughout the first weeks in the apartment that Guy is a self-centered, uber-macho, 60s man, its his role just as his frail wife Rosemary is a home-bodied simpleton (who just happens to read all the time). Guy is mainly interested in material wealth, he's only interested in Roman once he learns of his connections in the theater. Did you know that he knew Forbes-Robertson!? He often adorns Rosemary in cheesy impersonal gifts, such as cliched roses and clothes. When the couple leave the interview, Rosemary begs Guy to buy it for her, like a child. There are several other scenes involving currency and father-like control: Rosemary bets a quarter that she's pregnant, her "three gold stars", the arguement over the pricing of her doctors, and his constant preoccupation with fame.
Wealth in Guy's eyes means control, since he appears wealthy to Rosemary he has control over her. In truth, and to be short, he betrays Rosemary because he believed that she would adhere to her own gender role and be seduced by material wealth and fame. Rosemary has shown signs of that, she marries a man who is much older than her (financially secure?), she has no job of her own, and she reads magazines about high fashion and furniture (I saw it in a magazine) Its through this that Guy assumes that she would be fine with arrangement made with the cult.

When did Guy join the satanic cult?


Why is there Pesach Sheini - The Second Passover?

Question: What is the primary/basic reason why one has a second chance to bring the Korban Pesach (Passover Sacrifice) on Pesach Sheni (a month after Passover)? Other mitzvos, such as hearing the shofar or other special korbanos (sacrifices) do not have a similar way of making up for the missed opportunity.
Answer: The Chinuch (Mitzvah 380) says that celebrating Pesach is so important because it showed the whole world that G-d is in control and powerful, and has the power to renew/create the world ex nihilo. G-d gave us Pesach to celebrate this. Since this lesson is so important, if one missed the opportunity G-d gave him another opportunity to celebrate this.
Answer: Perhaps it is related to the fact that eating the korban pesach is one of two positive mitzvot whose transgression gives karet. The other such mitzvah, milah, can also be made up at a later time.
Answer: Actually, it isn't the only one. The korbanot brought on each festival also come with make-up days (7 or 8 days after the onset of the obligation).
Missed tefillah, which were modeled on korbanot, can be made-up for one period after the cessation of the previous period. For example, if one missed Ma'ariv, it can be made up the following morning up until the end of the Shacharit period.
The mitzvah of Milah is primarily the 8th day after birth, however if one misses it it can be made up afterwards. This is referred to as "Tashlumin" by the Rokeach and others.
The mitzvah of Havdalah can be made up for 3 days after the closing of the Shabbat. If one misses the night Seudat Shabbat, it can be made up the next day.
Fasting, if one couldn't do it, can also be made up on any subsequent day, preferably the very next day. (Today it isn't considered obligatory any more, due to the weakness of our generation).
Many other examples exist as well.
Comment: one could perhaps argue that all those make-ups are an extension of that mitzvah (e.g. one is required to make a separation between shabbos and the weekday - this obligation extends till tuesday night). Pesach Sheni, on the other hand is a separate mitvah. The Chinuch has it as Mitzvah 380 - http://hebrewbooks.org/pdfpager.aspx?req=34302&pgnum=244
Answer: The first reason I can think of is purely historical.
The origin of this holiday is an episode recorded in the Torah (Numbers 9:1-14). On the first anniversary of the Exodus, God commanded the Israelites to once again bring a Korban Pesach. There was a group of people who were inelligible to participate at the time due to recent contact with human remains. They went to Moshe and Aharon and asked why they should be prevented from being part of this Korban along with the rest of the Israelites. God responded by commanding them and people who might have this problem in the future to perform a make-up Pesach one month later.
So, you could say that the reason this holiday in particular has a make-up date is because this incident happened when the recurring holiday was just being founded, which didn't happen with other observances.
Of course, you're left with a few issues:

Why did people make a fuss about this observance and not about others (at least as far as we can see in the Torah)?
Didn't God intend this to be part of the Torah's rules before the incident happened?

I'm sure that plenty has been written about this, some of which I may try to look up later, but here's how I see it conceptually. The Korban Pesach demonstrates the bringer's membership in the Israelite Nation. One clue to this is in Exodus 12:26-27, where the Torah gives an explicit meaning for the observance: It represents God passing over the Israelite homes, which bore the blood of the Korban on their doorposts, when He smote the Egyptians.
Another clue is in the complaint of the people for whom Pesach Sheini was apparently founded. They specifically say "Why should we be prevented from bringing God's Korban ... among the Children of Israel?" Apparently, the tie to the community represented by this Korban was an important part of their concern.
So, I suggest that both these people's motivation and God's was to make sure that this central rite of affiliation was available to every Israelite.
May the Israelites of today once again demonstrate to God that we can't bear to be prevented from bringing the Korban Pesach, and may He respond by once again giving us an avenue for bringing it.
Comment: @nikmasi, the sources are Torah verses. It'd be nice to have some commentaries to help, but I don't think essential to this being a valid answer.
Comment: -1 this is interesting conjecture but needs sources
Answer: On pessach the obligations (מצווה חיובית) of every Jewish person is to eat at least a kesayis of a korban pessach. If the individual is Tamei, he/she cannot be מקים that obligation, and thus cannot fully observe all the pessach obligation
In contrast,. For all other Yamin tovim there is no specific chiyuv to bring and eat a certain korban. On succos, for example, everyone must shake the lulav, which even a tamei person can do. The korban that one would have to bring is an Olas Reiyah (if you were oleh regel to Jerusalem) , which even a tamei person can do by sending it to the bais hamikdash with a shaliach and not entering themselves. Meaning, that being tamei doesn't stand in the way of being מרים all mitzvos that are created by the Yom tov. This is why no second chance is necesssary
Comment: IIRC being Tamei isn't the only valid reason for missing the Korban Pesach triggering the possibility of Pesach Sheni?
Comment: @Yirmeyahu  Being בדרך רחוקה is another one, which to my point , is again something that would prevent the person from eating the korban


default xna 4.0 gametime don´t works well for 2D physics

Question: I am developing a game using Visual Studio 2010 and XNA 4.0,
after advancing to some extent with the project (a platform based 2d platformer msdn starter kit) I got to test it on different computers with different hardware (CPU, graphics, etc.) and I found that the speed of movement object of the game is quite different, I implemented the PSK physics msdn that are based on time,
<code>            /// <summary>
            /// Updates the player's velocity and position based on input, gravity, etc.
            /// </summary>
            public void ApplyPhysics(GameTime gameTime)
            {
                    float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
                    Vector2 previousPosition = Position;
                    // Base velocity is a combination of horizontal movement control and
                    // acceleration downward due to gravity.
                    velocity.X += movement * MoveAcceleration * elapsed;
                    velocity.Y = MathHelper.Clamp(velocity.Y + GravityAcceleration * elapsed, -MaxFallSpeed, MaxFallSpeed);
                    velocity.Y = DoJump(velocity.Y, gameTime);

                    // Apply pseudo-drag horizontally.
                    if (IsOnGround)
                            velocity.X *= GroundDragFactor;
                    else
                            velocity.X *= GroundDragFactor;
                            //velocity.X *= AirDragFactor;
                    // Prevent the player from running faster than his top speed.
                    velocity.X = MathHelper.Clamp(velocity.X, -MaxMoveSpeed, MaxMoveSpeed);
                    // Apply velocity.
                    Position += velocity *elapsed;
                    Position = new Vector2((float)Math.Round(Position.X), (float)Math.Round(Position.Y));

                    // If the player is now colliding with the level, separate them.
                    HandleCollisions(gameTime);
                    // If the collision stopped us from moving, reset the velocity to zero.
                    if (Position.X == previousPosition.X)
                            velocity.X = 0;
                    if (Position.Y == previousPosition.Y)
                    {
                            velocity.Y = 0;
                            jumpTime = 0.0f;
                    }
            }
</code>
tested eg with a PC (PC1) 2.13GHz Intel Core 2 6400 / ATI Radeon HD 4670
and another one: (pc2) 3.00GHz Intel Pentium D / Intel 82945G Express Chipset Family
by displacement difference (moving x axis at supossed (position = velocity * gametime.ElapsedGameTime.TotalSeconds) constant velocity, for example) is 3 seconds in a total of 20 (example: moving pc1 player sprite 6000 pixels in the x-axis at 20 seconds and pc 2 runs the same distance in 17 ).
Tested on a 3rd PC: i72700k / Gigabyte GTX 560 TI
the results are even worse, after some time after starting the game gets like 3 times slower and showing the number of pixels in each frame moved in a debug window in the game (counting updatespersecond with counter variable for updates cuantity and gametime for counting a second show 63fps), it appears as if the number is always constant ( refreshments lose the Update method?).
In this pc if I put the game in fullscreen during the course of the game, the effect of "go slow" is immediate and restore window mode sometimes yield returns to "normal" and sometimes not.
Eventually I began to try a new project to test whether the movement is constant in different pc loading only one sprite and its position value in screen printing.
Occur The same.
I even tried moving a constant amount of pixels explicitly (position + = 5) and different speeds in different pc quantities of pixels moved in x time.
I have the game loop as the default (fixedTimeStep=true;SynchronizeWithVerticalRetrace=true;).
I've also tried turning off and creating another timestep as discussed in different post (eg http://gafferongames.com/game-physics/fix-your-timestep/
but i can´t achieve the desired result, move the same number of pixels in X seconds on different computers with windows.
All pc used for tests use windows 7 enterprise pc1 == x86 the others are x64.
The weirdest thing is that I find information about people describing the same problem and that I wear long nights of searches.
Thanks for your help.
Comment: That's an interesting problem, I've never seen timing differences between different hardware sets for my XNA programs. I don't see anything off-hand that you may be doing wrong.
Answer: Problem "solved" the pixel amount difference between computers is because i have a fixedtimestep disabled and one of the tested computers monitor refresh rate is 75hz
If the monitor run at 75hz, in xna with isfixedtimestep=false and vsync actived the game run update 75 times per second.
When the two and more tested pcs are configured at 60hz in all of them works well and at same movement velocity.
Comment: If you want to understand more about how XNA handles timing, you may wish to read this:  http://blogs.msdn.com/b/shawnhar/archive/2007/07/25/understanding-gametime.aspx


When an iPhone app is updated and the minimum required iOS increases, what happens for customers who still have the lower iOS?

Question: For example, I'm a developer, and my app is released with a minimum iOS of 3.0 required.  If I release an update requiring iOS 5.0, what happens?
Can existing customers running 3.0 attempt to update?  What error message (if any) do they receive when attempting this?
Will customers running 3.0 get the 'Update' notification in their app store app?
Answer: When the user tries to install the update, the app store will alert the user saying something like "you must have iOS5 to install this update.". The user will still be able to use the current version they they have, though.
Comment: This is correct. Apple wants people to upgrade to the latest version of the OS so that they can benefit from the new features and the better security so they have a better experience and tell their friends about how much they enjoy the product.
Comment: Yes, the user will still see that there is an update for that app.  However, the App Store won't let the user download the app without the user updating their firmware version.
Comment: Thanks.  Do you know if they'll still receive the update indicator in their App Store app (even if they can't update)?
Comment: Thanks, I was waiting for someone else to confirm your answer first.  I've up-voted it as useful in the mean time.
Comment: @ruddfawcett Accepted.  Another way to get more rep is to up-vote the questions you've answered.  This gives them more visibility, hence more people to rate your answer.  ;)
Comment: Does anyone know if there is official Apple documentation about this?
Answer: Nothing. The app doesn't create any problem until it is deleted. To be re-installed, it requires update, after being deleted once.
Answer: As a user, I've found that iTunes downloads the latest app regardless of what iOS the user is using on their device.
iTunes downloads the latest app and deletes (or asks to delete) older app versions from the user's iTunes library – an unwary user will click Yes to deleting the older version, and will be happy to get the latest version.
It is only when the user tries to install this latest version on their device (after removing the older app from their device) that iTunes will then raise the alarm that it is not compatible with their device.
The user is then left without the older version or the update.
It is Apple's hope that the user has backed up their iTunes library prior to downloading updates to their apps. This is a different procedure than just using iTunes to back up their devices, which only backs up the Data on the users' devices and not their apps purchased (downloaded) through iTunes.
If the user doesn't have a backup, Apple does not maintain older versions of apps. So the user has no means of retrieving older versions from the App Store.


What makes airplanes pitch up during landing?

Question: So what exactly pitches the plane upward with the rear end down? Do flaps help lower the nose when deployed 80%-100% down with such low speeds?
Comment: The elevator is used to pitch up the aircraft just prior to touch down. That is a flap at the rear at the airplane that deflects upwards and thus pushes the tail down and the nose up.
Comment: It's not real clear whether you are asking about pitch torque generated by flaps, or about how flap deployment affects the angle-of-attack that correlates to a given airspeed, or about how the pilot controls the pitch attitude and executes the landing flare.  Looks like various answers have addressed various ones of these; probably too late to edit now as you may invalidate an existing answer.
Answer: The change in pitch during the landing is called the flare and it is controlled by the pilot (or autopilot for an autoland) using the elevators (i.e. pulling on the yoke). From the Boeing 737 NG FCTM (6.10 Landing):

When the threshold passes under the airplane nose and out of sight, shift the visual
  sighting point to the far end of the runway. Shifting the visual sighting point assists
  in controlling the pitch attitude during the flare. Maintaining a constant airspeed
  and descent rate assists in determining the flare point. Initiate the flare when the
  main gear is approximately 20 feet above the runway by increasing pitch attitude
  approximately 2° - 3°. This slows the rate of descent.
After the flare is initiated, smoothly retard the thrust levers to idle, and make small
  pitch attitude adjustments to maintain the desired descent rate to the runway.
  Ideally, main gear touchdown should occur simultaneously with thrust levers
  reaching idle. A smooth thrust reduction to idle also assists in controlling the
  natural nose-down pitch change associated with thrust reduction. Hold sufficient
  back pressure on the control column to keep the pitch attitude constant. A
  touchdown attitude as depicted in the figure below is normal with an airspeed of
  approximately VREF plus any gust correction.

The flaps are set much earlier during the approach phase. They are not changed any more during the landing phase.
Answer: Flaps help to increase the lift at low speed, allowing the aircraft to fly at a lower than cruise speed speed.
The pitch up is caused by the elevator on the rear wing.
Answer: For landing an airplane has to slow down. When looking at the lift equation,
$$L=\frac{1}{2}c_L(\alpha)\rho v^2A$$
We find that, to get constant lift $L$ with lower speed $v$ we need to increase either $c_L(\alpha)$ or wing surface area $A$ (we can't change the air density $\rho$).
Note the explicit dependency of the lift coefficient on the angle of attack $\alpha$. We can increase the angle of attack by pitching up, which is why planes generally have a nose high attitude on landing.
Flaps change either the lift coefficient for constant $\alpha$, the wing surface area, or both. This helps to reduce the required angle of attack, so the the pitch attitude may be reduced as well.
Answer: I don't know if your question relates to the approach phase or the flare. The later as explained above has to do with the elevator, the former i.e for the approach phase you will notice that airliners and even more so fighter jets come on the approach indeed with a high noze up attitude. That has to do with swept wings. Swept wings allow an aircraft to fly faster by retarding the speed at wich the wings will become supersonic. That's all fine, but the problem with that is (amongst other ones): it will reduce the lift generated by the wing therefore forcing the aircraft to fly at a higher angle of attack during the approach. Hence the noze up attitude of the plane during that phase.


I don't get notifications when I comment on pages I "Like". Why is that?

Question: Let's say I "Like" a specific page on Facebook and make a comment about it. I don't get notifications if someone either "Likes" my comment or writes a comment after mine. Why is this?
Answer: I don't think that's ever been a feature, has it?
As far as I know, you don't get notifications for subsequent comments to content you've commented on on pages (exception being when one of your friends likes your comment)
Comment: At one time it was, I remember I got notifications and emails for each one. At times, it was annoying but it good to see the back and forth banter. Now, it's totally done away with?
Answer: Could anyone intentionally have you reported on facebook (spam, hate speech, etc.) to cause it?.  That "was" a feature of Facebook´s social plugin. Can't find an explanation on facebook documentation about why it was removed (by the end of 2012). I used to receive notifications for every someone else's reply or "like" to my comments or posts on a news web page, no matter if others were friends or not.  Now, I only get notifications on replies.
Answer: If you like a fan page, you won't get notifications like you used to. This is because Facebook has pushed the page owners to "promote their posts" with money. In other words, the fan page owner must now pay Facebook a certain amount of money to reach a guaranteed amount of its followers. Without paying, the post will only reach about 10 percent of the people that liked the page.
Answer: When you comment on a post, click on the dropbox in the upper right corner of the post its self(Where Edit/Delete Post usually is), then click follow post. You will be notified of any comments made on that post.


What is the best way to sell sealed LEGO sets?

Question: My kids have inherited a massive LEGO collection. 90%+ is in mint condition, still sealed. There are thousands of sealed boxes - currently kept in storage. There are plenty of open sets that the boys will keep, but the bulk we are looking to sell. What is the best way to do this? Any advice would be appreciated. A large amount of sets are Star Wars.
Comment: I vote to keep this one open, since TJM is asking mainly about new and sealed sets in perfect condition. This excludes all efforts to check for completeness etc.
Comment: I've edited both this question and the linked possible duplicate to make it clear that this question is for NIB sets and the other is for open sets.
Comment: Possible duplicate of [What is the best way to sell complete LEGO sets?](https://bricks.stackexchange.com/questions/9339/what-is-the-best-way-to-sell-complete-lego-sets)
Comment: That sounds good to me.  It seemed like a dupe at first glance, but it was challenging finding the other "one".
Answer: If you really have that much (hundreds or more sets to move), you have some options:
Set up a Ebay store:
    Up front cost: None
    Profit: ~80% of net (Ebay takes a cut, Taxes, shipping materials)
    The slow burn option. You will eventually get rid of everything, but it will take some time, and many trips to the post office.
Go rent a table at a local Lego convention:
    Up front cost: probably a few hundred bucks
    Profit: After the booth /table cost, all the money is pretty much yours.
    This will get rid of stuff fast if you go to a sizable convention and you price reasonably. People buy a lot of lego at Lego conventions. You will have to plan this in advance, since tables might require being reserved months in advance.
Find a reliable Lego collector to sell it for you:
    I had a good friend who is an active member of the local Lego community do this for a family who acquired a huge vintage Lego collection. I think he took about a 20% cut and had most of it sold off in a few months. The upside of this approach is that you don't have to do anything but count the money you make. Make sure you get someone who knows what they are doing though. Older collectors are good choices, since they know a lot of the history of sets and themes.
I don't know how good sites liek Bricklink are for selling sets. It is a fantastic place to buy sell loose parts, but I don't know how quickly sets move there.


Is it possible to use two dictionaries at the same time in swype?

Question: I type in two languages regularly - depends on who I communicate with, in perhaps 60:40 or 70:30 ratio. Sometimes I even use words from both languages in the same text. Both languages are supported by Swype. But I can only select one of them at one time, so when I need to type in the other language I have to change the settings, which is quite inconvenient. Can I merge two dictionaries or activate both of them at the same time?
Comment: you can long-press on the letter Q to quickly change language on Swype
Comment: It's still inconvenient, multiple dictionaries active at the same time would be a neat feature.
Comment: wow you're right.. you can post that as an answer imo.
Comment: agreed. Still this is better than having to change the Settings.
Comment: I also recommend suggesting this to the Swype people.
Answer: you can long-press on the letter Q to quickly change language on Swype
Answer: You could also try to just add the words you use most of the time, even it is from a different language.
That is what I do. When I'm using one language, and I need a word that is available in the other language, I just type it and add it to my personal dictionary. Over time I will have two dictionaries who will probably both have the words I use the most.
Answer: Swype from swype symbol to q to quickly change between two most recently used languages.
Easy language change on the keyboard
Answer: Another Stackoverflow question about using multiple keyboards on Android: https://stackoverflow.com/questions/20197421/adding-a-second-dictionary-to-the-spell-check-in-android-4-3/44033793#44033793
Here is how for example to have a French keyboard with French dictionary + French keyboard with English dictionary
Go to Android settings > Language & Input > Gboard (Google default keyboard).
Then in Languages, you can tick all the keyboards you want. In my case, French (France) and English (UK).
This will give you the usual AZERTY French keyboard and the usual QWERTY English keyboard.
If you want the English dictionary with a French AZERTY keyboard, you can go to Preferences > Personalised input styles and create a new keyboard Language: English (UK) Layout: AZERTY, then in the Languages menu, you will have a new keyboard in the list, English (UK) (AZERTY). Tick it.
You now have 3 keyboards in your list: French (France), English (UK) and English (UK) (AZERTY).
While using the keyboard, you can then switch from one keyboard to another either with the special button or by holding the Space bar. The Space bar also shows the current language being used.
Using multiple dictionaries at the same time: In Text correction, there is an option called "multilingual suggestions", this will use several dictionaries at the same time, recognising as valid all words from the selected languages. If active, the Space bar will show something like FR-EN, to indicate that several languages are active at the same time. I personally don't like it.


Help Identifying Italian track frame

Question: Hi I would like to know the maker of this bike I brought back from my stay in Italy. It has been repainted, It isn't the original fork, and the serial located on the top of th bb is :1148591
Any clue ? Thank you.
Comment: This frame is older than 80's. Check the cottered cranks, shallow angles and long chainstays. The fork has drilling for brake and fender eyelets, both of which don't belong on a track bike. The frame doesn't have eyelets, unfortunately the photos don't show if the seatstay bridge has been drilled.
Comment: @Criggie Thanks for the response. I'm sorry you're right, it's the original paint. I meant the fork has been repainted, I noticed a green layer underneath and the guy who sold me the bike told me he replaced it, also the tint of the blue is slightly different.
Comment: Why do you think the fork is not original?  Its got the 80's rake and looks correct.  There's a brake mounting bolt there, but no caliper.
Comment: Also, the amount of paint skuffing suggests any repaint was long ago.  What makes you think it was repainted?
Comment: @ojs I could upload the picture but yes the seatstay bridge is drilled
Answer: This could be pretty much anything, you might want to find a specialist in lugworks. Many Italian frame makers had very unique lugging to determine their bikes from the rest. I used to know a few by heart back in the days when I was restoring old racers for Single Speed Co but I'm afraid that skill has fallen back now. Having unique lugs was especially important on older bikes.
I can't see on the photos what is happening between rear dropouts, it could be an old track frame but some older bikes never had the horizontal dropouts so it could just be an old frame designed as a single speed bike. It definitely looks older than 80's and even 70's are still questionable.
How is the weight on this?
Comment: The lugwork isn't the puzzling part. What's puzzling is the seatpost clamp **in front of** the seatpost instead of behind it, in combination with the lugwork. I know of a manufacturer known for their lugwork who also had a striped seat tube like that, but they've had their clamps behind the seatpost since at least the 1950s.
Comment: That is indeed very interesting. Sadly I won't be able to help with this but it is a very interesting frame you have there.

Help Identifying Italian track frame


Logic behind hikers yielding to horses?

Question: Here in California, a lot of trails have signs with a triangular diagram, showing that cyclists should yield to hikers, and both cyclists and hikers should yield to people on horses. I don't have a problem with yielding to horses, but what is the logic behind this? Not to startle the horse? Not to get your feet stepped on? In general, what is the polite way for hikers to behave toward people on horseback?
Comment: It's a safety concern, horses are animals-they spook. You put the rider at risk of getting bucked off or put yourself in the position of getting kicked if you spook a horse. I've ridden with guys that have horses that spook at every stump, low hanging branch, or shadow they encounter. Horses are big, if you get in their way they might think you're trying to pick a fight, a fight you will ultimately lose.
Answer: Generally "X gives way to Y" rules can be found not just on trails but on open water (steam gives way to sail) and in rivers and channels, even on city sidewalks. They seem to be based on these (potentially contradictory) reasons:

slower movers should allow faster movers to pass them and carry on away (after catching up from behind)
more nimble entities should nip aside where there isn't room for both entities
those that cannot move in certain directions (sideways is hard for horses; sailboats can't turn arbitrarily) should be allowed to keep on going while the other entity does the difficult/impossible move instead
those that can't go in some areas of the pathway (on the soft ground, into the trees, up a fence, in the shallow water) can have the right of way and the other entity can go to the margin or something to enable passing (in either direction)

In the case of horses and people, I see every one of these rules supporting that the person should get out of the way. Sure, in "steam gives way to sail" some of these are contradicted, because the rules point in different directions and they have to be reconciled somehow. But I don't see any logical reason why a larger, faster entity that can't do some of the things people can should be yielding to the slower yet more nimble human, who can do things like climbing a wall or fence to get out of the way.
Now, all that said, if this list determined the rules cyclists would be between people and horses, so horses would have priority always, then bikes, then people, and people would be ducking off the trail or climbing a fence to let bikes go by. But that's not the rule on your signs, so it's possible my logic doesn't apply.
Comment: The point of putting cyclists last might be getting them to pay attention. While it's hard to get startled by a horse, cyclist can come down paths no wider than a person with relatively little sound at pretty breakneck speeds. Hikers might be carrying heavy loads or have reached a certain age and be unable to duck out of the way quick enough even if constantly aware of the possibility. By making it the cyclists responsibility they have to mind their environment and if needed slow down as a precaution.
Answer: In the Grand Canyon, it's because it's easier for a human to get off the trail than it is for a mule.  I suspect the same reasoning applies in most places.
Answer: The safe and courteous way to handle an encounter with stock (horses, donkeys, etc.) is to step off the trail to the downhill side, and also to talk to the riders.  This helps the animals know you are a human and not a predator, and it moves you clear of their path should they spook.  Horses are prey animals and may be sensitive to potential threats from above them, and may also be confused by people wearing large backpacks.  (They also tend to bolt uphill when spooked.)  Allow them all to pass, keeping in mind that less-experienced or problem horses are likely to be placed last in line.  I also suggest giving the rear of any horse a wide berth.  They can't see what you're doing back there, and you don't want to risk a kick.
Generally speaking, right-of-way rules tend to favor the least maneuverable.  In this case the 1,000 pound quadruped wins, not just from a maneuverability standpoint but also due to unpredictability (it might spook, bite, kick, or otherwise ignore its rider).  In terms of the priority of cyclists vs. hikers, there is occasional animosity between the two groups that may have affected the rules, similar to how many ski resorts heavily restricted snowboarding when it was first starting out.

Trail Etiquette and Safety
Comment: interesting info about uphill/downhill. I was told on a safari once that leopards, cheetah etc are very bad at running up hills, while antelope etc are better. Perhaps this also applies to mountain lions and horses?
Comment: @KateGregory for Horses it depends on the breed, once in an uphill race I took my friend on a corner by taking the outside, her heavy cob struggled but my leaner Welsh Section B took the longer (and steeper in this situation) corner better and I overtook.
Answer: It's a similar situation here in the UK. We have routes which are designated as Bridleways which Horse-riders, Cyclists and Pedestrians can use but not motorised vehicles.
I would imagine that the yielding to horses is because some horses can get spooked easily and it is safer all round to keep relatively still and let the horse and rider to pass.
Answer: Having had horses myself, here in England, part of the reason you give way if you hear a horse coming on a Bridleway is because (and I say this having been in the situation) there is no speed limit for horses on Bridleways (some might have a trot sign but not always), if you're cantering or galloping along which you have every right to do it's harder for us to stop and wait than it is for people to step over. Horses at speed are dangerous to horse, rider and spectator. We giveway to bikers in my area for the same reason, they ring their bell, we move over. Same to joggers. My area in general seems to have an etiquette of slowest mover stops.
I admit that is also incredibly rude to gallop past someone, but there is some historic value to that with UK hunts. Dog and Riders trump people and cars when any form of UK Hunt is being undergone.
On roads, horses are inherently skittish, but not always. Anything from a plastic bag to a lorry's air brake may but not necessarily will set a horse off, which is why in the UK horses on the road trump cars, cars must slow down and pass slowly, emergency vehicles turn off sirens etc. I once even had armed forces slow their march for us as we rode through their land.
Regardless, in the UK as well the rider must make themselves clearly known - high vis is required to walk on our roads, and in general this means you should on a bridleway as well. Part of hacking etiquette around where I am from. In some locations where walkers are common you might also need a license to hack, I've had this in public woodland.
In my experience as both horse rider and hiker, it's best for the hiker to step over and wait, and for the rider, whether of horse or of bike, to slow down (if possible) and say thank you ... you will be surprised how many people don't. For the most part around Buckinghamshire, simply being a walker / biker / outdoors person will put you in a sort of polite and thankful outdoors social circle. Many walkers, and various riders, will say 'Good morning / Afternoon' or 'Hello' to you as you pass, and for the most part they remember to say 'Thank you' as well.

what is the polite way for hikers to behave toward people on horseback?

As for that, you answered it yourself really, be polite. That's all I ever expected as a rider, and it's all I do now as a hiker.

Logic behind hikers yielding to horses?


How does decalcifying work, and is it something I need?

Question: We recently had to replace our water heater because of lack of hot water, age (12 years to the day almost) and sediment build up (it was higher than the lower element; we purchased the home 7 months ago). While the plumber was here (we had extreme difficulty getting the elements out to initially change that we opted to call in a professional) he told us that our pipes are most likely in need of decalcifying, which is a product they sell for just over $2000. We are not handy people, nor do we know a lot about plumbing which is why I am asking lots of questions to get some answers before going forward with such a large purchase. Can anyone tell me about this process, if it is needed, if it is something we can sit, etc etc.
Answer: There is no relationship between tank sediment and pipe calcification. Unless he was able to show you how your pipes are actually constricted, such as where they connect to the water heater, there is no way anyone can know there is such a problem.
Unless you were shown obvious evidence of build up, this sounds like a complete scam to me from what little information you've provided. I would never call these people again.
AFAIK, calcium build up only occurs where very hard water is exposed to air, it does not build up inside of pipes. You may recall seeing elaborate calcium formations near commercial hot springs built up over decades by spraying hard water out of a small pipe. Despite the huge build up outside, the pipe continues to flow without evidence of obstruction after decades of use.