Is grease good or bad for guitar strings?

Question: I was once told that playing a guitar with greasy fingers was actually good for the strings. However, this seems a bit counter-intuitive. Is there any truth behind this claim?
Answer: Disclaimer: I'm not an expert in this, yet try to make an attempt to summarize what I know on this subject.
What does Grease consist of?
Grease consists mainly of dirt, dust and sweat.
Dirt and dust consist of human skin cells, plant pollen, human and animal hairs, textile fibers, paper fibers, minerals from outdoor soil, and many other materials which may be found in the local environment. Most of these are soft so for these it's rather a concern about how they make your string look...
Sweat consiss mostly out of water (H²O), some urea (A water-soluble organic compound, CO(NH²)², formed by the metabolism of proteins.) and a bit of salt (NaCl). Water isn't harmful at all, urea isn't either (unless you somehow manage to nitrate in which case it comes highly explosive). So our main concern should be the salt in terms of the life span of your strings, as it is a corrosive material...
Let's see how these affect different types of guitar strings.
Nylon Strings
Here, your main concern is how your strings would look, as dirt/dust/sweat can stay on your strings.
Nylon strings are corrosion-resistant and doesn't have a problem with salt.
For example, imagine a guitar that has been in your basement for a very long time, if you blow at the strings a lot of dust will come of. Unless you properly stored it inside a bag... :)
Metal Strings
What applies for the nylon strings also applies here.
But an extra concern here is that salt is a corrosive material against metal, so technically, cleaning your guitar after practicing and performance can help to increase the lifetime of your strings.
Is it worth cleaning my guitar strings? How do I do it?
I would say, yes, because they will look less dirty and more shiny. And for metal strings you have the added benefit that the lifetime could be longer, so it's certainly something you could consider doing.
Wikihow has a nice guide explaining this, alongside tips and warnings; a summary:

Lay the guitar on its back, resting the head stock on small box or similar, to stop the machine heads going out of tune.
Grab a sheet of towel/cloth and fold it in half length wise. Fold it length wise again so you have a long rectangular piece. Do the same thing to the other sheet. This one will be the "Oiling Rag".
Slide the dry sheet under the guitar strings just near the bridge, then fold it over so the other half covers the top of the strings.
Now, slide this piece along the length of the strings, right up to the nut. Apply some downward pressure to clean the top part, and pull up on the paper to clean the underside of the strings too. (This is just as important as the top) Even if the head gets lifted off it's mount, it still helps.
If you notice a little bit of muck and dirt on the towel, then you're doing fine. It won't always be like that, but this step helps set the strings for the oiling.
Optional, as doing it unproperly is bad for the wood: Apply some WD40 to one side of the other piece of paper towel and wrap it around the strings the same way as the first piece. Run this piece along the length of the strings using the same process as before.
When that's finished, the strings should look noticeably shiny (and be very oily) and smooth to touch.
Comment: Good comprehensive answer.
Answer: Definitely bad. Grease is sticky, ideal for lubricating things which need high viscosity.
it holds particles of grit, dust, anything, and can hold moisture in.
Guitar strings should be kept smooth, away from moisture or anything which could corrode or rust them, and you don't want grease or grit on your fretboard.
So stick to a wipe with a dry cloth, Fast Fret and your strings will last much longer.
Answer: Oil prevents metal from oxidizing.  Salts are corrosive.  Sweat is both!
Overall, I'm pretty sure the salt wins out.  My guitar strings always do worse when I don't keep them clean, and I've always been told that they should be cleaned after playing.
I wouldn't recommend oiling your guitar strings either, though.  It'll get into the wood and make it gross, as well as altering the feel and sound of the strings.  It's best just to keep them clean.
Answer: The question is a bit vague as to what good and bad mean, the answers here are talking about lifespan, but it is also worth considering that as strings get dirtier it changes the sound (note - I'm an electric guitar player, things may be a little different for acoustic/classical, but I expect they'll be similar). Try comparing a brand new set of strings to an older set and you'll hear that the new clean ones have more jangly top end. Most people seem to prefer the sound of new strings, so keeping em clean would be a good thing. Me, I prefer older strings myself, so a good bit of skank makes me happy :) That said, grungier strings don't intonate so well either. Ho hum.


How much did The Lord of the Rings cost when it was first published in 1954/1955?

Question: What was the original price (first edition/first printing by Allen & Unwin, London) of The Lord of the Rings books when they were first sold in 1954/1955?
Comment: In which country? The UK? And are you referring to the three volumes together? I think the third volume was published in 1955.
Comment: If you still care about this question, could you please edit it to make it more specific? Don't be intimidated by the "on hold" status. If you clarify the above points, the question should get reopened again.
Comment: @ChristopheStrobbe I suppose that I could have been more clear. I meant in the United Kingdom, and the first volume of the trilogy. I did get the answer that I was looking for, however. Thank you for responding to my question.
Answer: Tolkien himself reflected on the original prices of his works, which was twenty-one shillings (one Guinea) each.
The price seems to have been high for the times but set because that was the lowest amount for expenses to be paid.

Very many thanks for remembering the ageing Professor, and bracing him up with your letter. I know  21/-  is  a  frightful  price,  but  don't  forget  that  I  have  to  sell  an  awful  lot  before  the  ghastly expenses are paid off. The fact that I get not a halfpenny until that is done, does not matter so much, as this: if enough are sold I may be able to publish more. So add to your great kindness in inducing such as you can to beg borrow or steal a guinea rather than a copy!
Letter 136, To Rayner Unwin, 24 March 1953

Tolkien wanted the publications to be a bit more fancy but that would have cost more money...

Pictures are far too expensive, even if I had sufficient skill to do them and cut out artist's fees. I tried, but alas! can only draw v. imperfectly what I can, and not what I see. The wrapper is all that survived of three separate designs I made, one for each pan. Part I was to have been all black with red and gold letters, and the three opposing rings: Narya (red), Vilya (blue), Nenya (white). . . . .1 But  it  was  reduced;  and  the  lovely  (I  thought)  facsimiles  of  the  3  burned  pages  of  the  Book  of Mazarbul also vanished – so that folk could have the thing at the trifling cost of 21/-!
Letter 151, To Hugh Brogan, 18 September 1954
Comment: You might want to add in this image from the [first edition copy of FOTR](https://www.peterharrington.co.uk/blog/identifying-collecting-tolkien-first-editions/); http://dev5.peterharrington.redfishgroup.co.uk/blog/wp-content/uploads/2012/01/69597_3_Tolkien-602x700.jpg
Comment: @Valorum Since that image is copyrighted, I would only link to it instead of adding it to the answer.
Answer: The website The Tolkien Bookshelf specialises in rare books by or about Tolkien. It has images of many older and original editions, for example:

The Lord of the Rings, 1st UK Edition, 1st Impressions with Original Dustjackets (London: Allen & Unwin, 1954) and
The Lord of the Rings, Comprised of The Fellowship of the Ring, The Two Towers, and the Return of the King, 1st UK Edition, 1st Impressions, with Custom Clamshell Case (London: Allen & Unwin, 1954).

When you look carefully at the images of the dust jackets, you can see that they all have the same price: 21 s net. This means that the three volumes together would have cost 63 shillings (net).
Now 20 s = 1 £, but how much is that in today's money? The Currency converter: 1270–2017 of the National Archives can help: you select the closest year (1955) and set 1£ and 1s for the price of a single volume. According to the converter, this amounts to £25.06 in 2017 (for a single volume).


Migrating to other SE sites?

Question: Is it possible for users with 3000 reputation to vote to migrate a question to another SE site? If not, is it possible for ♦ moderators to do so?
Answer: For 3k users: Partially.
Users are only allowed to vote to migrate to sites that have shown a need for it. In our case, the only site users can vote to migrate to (besides our own meta) is Stack Overflow:

We haven't migrated enough posts anywhere else to warrant adding migration paths for them, but that can always be reconsidered in the future.

For ♦ mods: Yes.
On the rare occasion where you do see an off-topic post that belongs on another site, vote to close as off-topic and flag for mod attention. Mods can migrate the post to any SE site (including betas). If we start to see a pattern of migrating to the same site frequently, we'll try to get a migration path there so 3k users can handle it directly
Comment: ++ maybe featured tag this question too so people see it. I think they need a different UI though. For now I'd just like migrate to the trilogy sites.
Comment: @xeno If it comes up again I'll feature it. And yeah, I imagine they'll come up with a new way to handle the migration options. I think they're only going to add migration options for somewhat similar sites (so we won't have a migration option for Cooking or Bicycles, since it's unlikely people will post those questions here), and I picture it looking something like [this](http://mrozekma.com/so-mock-se-close.png) (totally made up though, it may be nothing like that)
Comment: @MichaelMrozek I think this feature should be available to 3k users, too. Recently I tried to flag a post for being off-topic, but could not specify, which site I think it should be migrated to, because I could only suggest the meta page and SO.
Comment: @polym I don't really control that. There are suggestions on the [main meta](http://meta.stackexchange.com/) for ways to improve it, but they're pretty reluctant to just let everyone migrate wherever they want. The best method for now is to just flag for mod attention and say which site it should be migrated to

Migrating to other SE sites?


Silly question about functors

Question: This question is probably trivial but I'm confused anyway.
Say I have a function $f$ between two sets, then it is in the definition of a function that for one $x$ in $X$ the value $f(x)$ is unique. Hence a function is not well-defined if $x$ is mapped to two different values. The word "unique" is usually in the definition.
The definitions of a functor $F:C \to D$ between two categories $C$ and $D$ usually just say that an object $X$ in $C$ is assigned to an object $FX$ in $D$ and the same for morphisms. I guess its silly to allow an assignmnt where $FX$ is not unique right? What if $FX$ is unique up to (canonical) isomorphism or something like that?
Answer: A functor $\mathcal{C} \to \mathcal{D}$ by definition is a pair of functions $\operatorname{ob} \mathcal{C} \to \operatorname{ob} \mathcal{D}$, $\operatorname{mor} \mathcal{C} \to \operatorname{mor} \mathcal{D}$ satisfying various axioms, which I'm sure you know. In particular, if $X$ is an object in $\mathcal{C}$ then there is a unique object $Y$ in $\mathcal{D}$ such that $Y = F X$. There really is no scope for confusion here.
If you want a notion of "functor" where the "value" is only unique up to isomorphism, then perhaps you should look at anafunctors: an anafunctor $\mathcal{C} \to \mathcal{D}$ is a triple $(\mathcal{F}, P, Q)$, where $P : \mathcal{F} \to \mathcal{C}$ is a fully faithful functor that is (strictly) surjective on objects, and $Q : \mathcal{F} \to \mathcal{D}$ is any functor. The "value" of $(\mathcal{F}, P, Q)$ evaluated at an object $X$ in $\mathcal{C}$ is defined to be any object $Y$ in $\mathcal{D}$ for which there exists an object $Z$ in $\mathcal{F}$ such that $P Z = X$ and $Q Z = Y$. Note that if $Z'$ were another such object, then the fact that $P$ is an equivalence of categories and $P Z = P Z'$ implies there is a unique morphism $e : Z \to Z'$ in $\mathcal{F}$ such that $P e = \textrm{id}_X$; of course, $e$ is an isomorphism whose inverse is the unique morphism $e' : Z' \to Z$ such that $P e' = \textrm{id}_X$, so $Q e : Q Z \to Q Z'$ is an isomorphism. Thus the isomorphism type of the "value" is uniquely determined.
Comment: Thanks, I'll look it up. It definitively helped me out.
Answer: No, $FX$ really is unique. A functor $F : \mathcal{C} \to \mathcal{D}$ assigns to each object $X \in \mathcal{C}$ a unique object $FX \in \mathcal{D}$.
Answer: The value of a functor $F$, call it $F(X)$, should be uniquely determined. Usually this requirement should not cause any problems.
Sometimes you might find two functors that essentially do the same thing. For example, let the functor $F$ on sets be the identity functor and let $G(X)=\{\{x\}:x \in X\}$. In this case, $G$ is different from $F$, but not in an interesting way. $F$ and $G$ isomorphic functors, which means for all $X$, $F(X) \equiv G(X)$ "naturally".
Here's another situation. Consider the category $Bij$ of finite sets where morphisms are bijections. Let functor $F$ assign to a set $X$ a set of possible linear orderings on $X$ (there are $n!$ ways you can order $X$) and let $G(X)$ be the set of all bijections on $X$ (there are also $n!$ bijections). Even though $F(X) \equiv G(X)$ for all $X$, there is no longer a "canonical" way to pair orders and bijections; $F$ and $G$ are not naturally isomorphic.
Comment: Actually, $F$ and $G$ are not naturally isomorphic more because the automorphisms of $X$ act on $F X$ and $G X$ in very different ways. (The "transport of structure" action on $F X$ is transitive, whereas the conjugation action on $G X$ is not.)

Silly question about functors


what platform choose for mysql

Question: which platform (operation system) better to choose for best MySql performance? windows or linux?
coonections pool for websites use or not?
Answer: If you have a choice I recommend putting it on a Linux box. The reason being that the Linux version is developed first and then ported. Whenever possible I like to install software on its "native" platform. I just seem to have less trouble that way.
Answer: It's essentially whatever your Ops team and hardware vendor can support, but one word of warning:
DO NOT run MySQL on a 32-bit system. Never. You will run out of address space then have a world of pain migrating.
Connection pooling isn't that bad, but you may get just as good performance without it, and it adds significant risk of bugs - connections can get left in a bad (or funny) state which breaks subsequent requests, often quite subtly. I would recommend not using pooling or persistent connections (e.g. on Apache).
On the other hand if you have a long-running daemon process, IT may want to hold connections open for its own use, as nobody "else" will use them.
Answer: If you'll be using a dedicated server, go for Linux - much easier to disable all the other stuff you won't need for a MySQL server; also, easier to tweak all kinds of parameters (TCP/IP stack comes to mind).
Answer: In general I suggest Linux. However if all your sysadmins only know windows, then forcing linux on them is a bad idea. However if you are the sysadmin team, and you don't mid either, go with Linux.
Answer: +1 for Linux, however. This all boils down to the system administrator you have available, if he does not know Linux, then what?
If your SA has never touched Linux, I would not recommend going to that platform. Hosting Linux on a production environment if you're a windows guy, is not like playing around with Ubuntu at home.

what platform choose for mysql


Distribution with Hadoop installed

Question: Is there any Gnu/Linux distribution that provides by default an Hadoop installation?
Answer: Not sure of a stand-alone Linux distribution but you can get a VM with pre-installed Hadoop here:
http://hortonworks.com/download/
http://developer.yahoo.com/hadoop/tutorial/module3.html
Comment: http://ydn.zenfs.com/site/hadoop/hadoop-vm-appliance-0-18-0_v1.zip
Answer: There is no GNO or linux distribution with hadoop.
What can be done is to use a pre-configured sandboxes from cloudera and hortonworks.
Second, what would be even more good if u set-up a standalone on your local. Although this is pretty tiring may be , as it might take a lot of your time.
But from my experience it gives a better understanding of the ecosystem.
There are several tutorials available to to that. just search bogotobogo on google. I liked this tutorial.
Also once hadoop deployment is done successfully, do try your hands on Spark. Its fun and great learning once you see its processing power.
All the best!!
Answer: There is no "distribution" per se but you can give the ambari project a try. It's an apache project that is a set of automated scripts and related plumbing to install and monitor a Hadoop installation. You even get a web based gui with it that you can use to monitor your install and restart:stop services etc. It'll even let you do a clustered install. Try it.

Distribution with Hadoop installed


How can I adjust my Facebook settings so I see when friends make new friends?

Question: In the past, my Facebook wall showed me when a friend had made a new FB friend, and also told me who that friend was. Now, my wall does not show when any of my friends make a new friend. This only shows up on my ticker, which I never check.
Answer: You can add them to the list Close friends. Every action of them will be shown, including adding new friends or following someone.
No one know your Close friends list, neither those in this list.
But you will be able to see such notifications only if your friends allows to share it with their friends.
Answer: If you have a list of friends you want to see this information about - add them into a list from here + click on Create List. One option is the to add them to a list called Close Friends, as Shinigamae suggested. I prefer a custom list, since Close Friends will notify you on any post they make and will probably make you feed centered around these people (it's a Facebook list).
After doing this friend-adding activity you can just navigate to your lists (with the same link from before), pick a list and see all their activity (not just which friend they have added).


Couldn't dual boot Vista and Centos 5.4

Question: Today I have installed Centos 5.4 with dual boot with Vista. Everything was fine, but after testing Centos 5.4, when I tried to load Vista, it did not load. After selecting vista from grub menu, it shows the following message:

rootnoverify (hd0, 1)
chainloader +1

No bootmgr found

I googled and try to fix the boot but failed, Then I restart my machine, boot with vista cd and in rescue option, restore my bootmgr by typing bootrec /fixmbr
What happened after that, I can load at vista now, but no grub menu shows :P It seems the Centos went totally invisible. I am using dual booting Ubuntu 9.10 and vista in my laptop and its working fine and with no error from the beginning. But installed Centos for one of my project needs and I need it running asap. So I am feeling very helpless. Please help me anyone out there. I know there are many people knows how to fix it. Please help me..
Thanks in advance.
Answer: When you restored the Vista boot manager, you lost Grub. You'll need to recover Grub as described in this answer.

Couldn't dual boot Vista and Centos 5.4


Special relativity version of Feynman's "Space-Time Approach to Non-Relativistic Quantum Mechanics"

Question: I'm looking for an article that sets up the framework described by Feynman in Space-Time Approach to Non-Relativistic Quantum Mechanics, but in Special Relativity.
Answer: Dear mtrencseni,
the special relativistic counterpart of the 1948 Feynman paper you mentioned is the 1949 Feynman paper
http://web.ihep.su/dbserv/compas/src/feynman49b/eng.pdf
called "Spacetime Approach to Quantum Electrodynamics". Note that I used the same Russian server haha. Well, more precisely, Quantum Electrodynamics is one important example of a quantum field theory but the general methods in the Feynman paper were only updated in their "technical details" when people needed to get the similar description for any quantum field theory.
If you were expecting that the special relativistic version of the 1948 paper would still be essentially the same thing, with some $p^2/2m$ replaced by $mc^2/\sqrt{1-v^2/c^2}$, you must feel disappointed. But in fact, it is a reason for a huge happiness.
The fact is that when special relativity is added to the quantum mechanical framework, one immediately encounters many effects that force us to use a fundamentally different classical starting point - field theory instead of quantum mechanics. Why?
Well, if you work with quantum mechanics - whether in an operator framework or in the path-integral approach - it doesn't respect the Lorentz symmetry. To respect the Lorentz symmetry, you need to switch from the non-relativistic one-particle Schrödinger equation to something like the Klein-Gordon equation or the Dirac equation. Both of them have a path-integral description as well although it is a bit subtle.
Take the latter - the Dirac equation - because it's relevant for the same electron that used to be described by the non-relativistic Schrödinger equation. One can show that because of relativity, the equation inevitably predicts solutions with negative energy. While $E=p^2/2m$ only has non-negative values of energy, the condition $E^2-p^2 c^2-m^2 c^4$ has both positive and negative values of $E$ as solutions. You can't avoid it - the squaring of $E$ is a fundamental feature of special relativity.
And indeed, the Dirac equation may be showed to have negative-energy solutions as well. If particles could have arbitrarily low energies, there would be an instability. You could get any energy from an electron, while the electron would be falling to arbitrarily low, negative energy levels.
Nature avoids it because it tries to find the lowest-energy state, dissipate all the excess energy, and call the lowest-energy state "the vacuum" or "the ground state". That's the only way to guarantee that it will be stable. So Nature actually fills all these negative-energy states - it has no choice. There is this "Dirac sea" of negative-energy electrons everywhere. By the Pauli exclusion principle, there can be at most one electron in each state. So the vacuum has 0 electrons in positive energy states and 1 electron in each negative energy state.
If there is a hole missing in this sea of negative-energy electron states, it will look like minus one electron with negative energy, i.e. it will be a positively charged particle, the positron, with a positive energy and positive charge. That's how Dirac predicted antimatter that was abruptly found. He got his Nobel prize for that.
Moreover, in relativity, you will find out that the pair creation of particles is inevitable. The number of particles can't be conserved. In some sense, it's because particles can move back and forth in spacetime - and the particle moving backwards in time is an antiparticle.
For all these reasons, you need to study quantum field theory if you want to combine special relativity with quantum mechanics. By quantizing a classical field, you get a system that looks like a system of particles once again. The number of particles coming from the quantum fields turns out to be integer (in the non-interacting limit) because of the same reason why the energy of a quantum harmonic oscillator is equally spaced. You will be able to recover the mechanics in the non-relativistic limit. But you won't be able to get rid of the phenomena that are implied by the fields - such as the pair creation and pair annihilation. They're real and important.
Relativistic non-field quantum mechanics is kind of inconsistent - or at least, it's not a viable approach to describe the real world. So you will only spend a very limited time with this concept - and you should eventually move to quantum field theory. This is true regardless of the formalism - Schrödinger's equation for the wave function, Heisenberg's equations for the operators, or Feynman's path integral approach. What I say about the fields is a physical insight and physical insights are independent of conventions and the choice of the mathematical machinery.
Best wishes
Lubos
Comment: I'm not sure the relativistic non-field QM is inconsistent, it just clashes with the Born interpretation (of course it can't be completely accurate since at high energies the number of particles is not constant). QFT has serious problems, so some of this is the pot calling the kettle black, eh? Relativistic particle QM agrees with experiment at low energies and clashes some with the usual framework of QM we all got used to....QFT agrees with experiment better but has foundational problems.  I think it is a myth that QFT has solved the problems with Rel. QM so now we can just forget about it.
Answer: Feynman published another approach to the path inegral method applied to the single particle Klein-Gordon equation in Appendix A of: Feynman, R. P., "Mathematical Formulation of the Quantum Theory of Electromagnetic Interaction", Physical Review 80, 3 (1950), pp. 440--457. In this appendix he replaces the Klein-Gordon equation with a Schrodinger-like equation with a fifth "time" variable.  This trick was first utilized by Stueckelberg and also quite early by Fock.  It allows for a positive definite probability density, and a localizable relativistic Schrodinger position operator.  It puts time and position on the same footing and allows a manifestly covariant description.  Many other researchers have studied this type of equation more recently. In some modern variations of this type of theory the mass can go off-shell, even classically.
Answer: What is described above is something called the "world-line approach" to quantum field
theory, which is similar in spirit to the non-relativistic "sum over particle paths" picture of the Feynman/Hibbs book. See for instance

Christian Schubert,
  "Perturbative quantum field theory in the string inspired formalism",
  Phys.Rept.355 (2001) 73-234,
hep-th/0101036.

As Luboš already pointed out, you do need to put in particle creation/annihilation more
or less by hand, but the method can nevertheless be a useful computational alternative to
standard quantum field theory methods (especially when dealing with non-trivial vacua, e.g. in the background of electromagnetic fields).
Answer: The method introduced here by Feynman is the Path Integral approach to quantum mechanics. When trying to include special relativity, you also need to move from quantum mechanics to quantum field theory. The path integral approach is then also referred to as Functional Integration.
There are many, many books on the subject since it's now considered a standard tool in quantum theory.
Some references are:
A book by the man himself:
Feynman, Hibbs and Steiber
The tome on path integrals is:
Kleinert
Some books treating Functional Integration and QFT are:
Nair
Peskin and Schroeder
...and pretty much every other modern day QFT book.
Answer: For the full framework, as MisterO explained, any modern textbook on QFT will do (I personally like Tony Zee's book (Quantum Field Theory In A Nutshell) most.
At the end of the paper that you refer to, Feynman remarks "There are other ways of obtaining the Dirac equation which offer some promise of giving a clearer physical interpretation to that important and beautiful equation." I think he refers here to his checkerboard model that he never published (although years later he included it in the book he co-authored with Hibbs. So, as a stepping stone to the full framework, you might want to investigate this Feynman Checkerboard model (there is a lot of material on this toy model on the Internet). And of course the very accessible book QED by Feynman (which, however, is really directed to a lay audience and does not explore the relativistic aspects) can also be helpful to grok the basics of QFT.


Does WiFi broadcast traffic from a station go through the access point?

Question: Let's say I've got two devices connected to my Access Point, a laptop and a tablet. If the laptop sends unicast traffic to the tablet, I understand that it must go through the AP.
However, how is broadcast traffic from the laptop handled? Does this traffic too go through the AP, or is it sent from the laptop to the tablet directly?
Answer:
Does WiFi broadcast traffic from a station go through the access point?

In infrastructure mode, clients typically only send traffic to the AP (ignoring exceptions such as 802.11z capable clients). As such, clients don't typically broadcast traffic, even when the traffic is broadcast. Rather it is unicast to the AP which in turn broadcasts the frame.

However, how is broadcast traffic from the laptop handled? Does this traffic too go through the AP, or is it sent from the laptop to the tablet directly?

Since any single client on a wireless network is not assured to be able to reach every other client, clients send their broadcast traffic to the AP as a unicast (which uses higher data rates, as I will get to in a minute). Since to be connected to the wireless network each client must be able to exchange frames with the AP, only the AP has any level of assurance that traffic it sends can be received by all clients.
So when the AP receives traffic to be broadcast, it performs the role of broadcasting the frame to the network, including both the wired and wireless side of the network. On the wireless side, the AP will use the lowest base/basic/required data rate that all associated clients can support. This helps to ensure that each client will receive the broadcast.
However, some wireless systems can perform a broadcast-to-unicast conversion which makes the AP send a unicast frame to each client instead of a single broadcast frame. There are a couple of reasons that this may be implemented. First, unicast frames are often sent at a much higher data rate, so it may actually take less "airtime" to send multiple fast  unicast frames rather than one slow broadcast frame (for example, 10 frames at 200+ Mbps vs one frame at 6 Mbps).
Second, broadcast frames are not acknowledged by the clients, so there is no way to determine if the clients actually received it. With unicast frames, each client will send an ACK for received frames and if the ACK is not received the AP will retransmit the frame.
Answer: In infrastructure mode (using a WAP) everything runs through the WAP. For example, your two hosts will be in range of the WAP, but may not be in range of each other. Also, one of the devices may be at such a distance from the WAP as to need a lower rate, which is why broadcast and multicast traffic on Wi-Fi is sent at the lowest rate of the WAP.
Comment: Could you tell me the point of the Group Transient Key if the broadcast traffic goes through the AP?Why can't the device wanting to broadcast just encrypt the traffic with it's Pairwise Transient Key and send it to the AP, and the AP retransmit it to each of the end points using their respective Pairwise Transient Keys?
Comment: You are now asking a different question that should be asked as a different question, rather than in a comment.
Comment: here it is https://networkengineering.stackexchange.com/q/54236/46547


Trumpet and braces

Question: I am a sophmore and I play trumpet. I am a decent player in symphonic band first chair for 2 yr and a half so i am deciding to audition for honors band. It is only next week to audition for it. I've been working hard to be in honors but there is a problem. I have braces and my braces will come off the month after the auditions and the month before honors band. I don't know if I should audition with braces though it will come off or wait until next year. I just don't know how I will sound without my braces playing my trumpet. What should I do?
Answer: What you do is not worry too much about hypothetical future problems.  You're currently a 'decent player'.   Good.  Play the audition, with the braces, get the place in honors band.  Don't even mention the braces in the audition.  What are you trying to do, give them reasons NOT to choose you?   IF removing the braces messes up your playing, deal with it then.
But it won't. I play trombone.  I had a brace.  It came off, I continued playing and barely noticed the difference. So will you.
Trumpet players need confidence!
Comment: I must look up what 'sophomore' means one day!
Comment: Thank you so much for your help Laurence! I'm going to let my my band director know I want to audition.
Comment: It's the second year of a four year 'high school' in the US.  Or the first year of a three year "senior high" (these used to be more common). You might see Middle School (6-8th grades) and High Schools (9-12th grades) in most school districts today.  The term is also used in four year college programs.  The total progression being Freshman, Sophomore, Junior, Senior.
Answer: A few things to consider. Everyone handles braces (and removal of braces) differently. There also a lot of different types of braces being used now which can effect how much they interfere with your playing with them on, and in some cases after they are removed as well.
It's been many years since I had my braces removed, but I still remember the difficulties of playing trumpet with them and afterward. The type I had back then had much more pronounced wires and thickness than designs used today, but in general I think the problem is quite similar. That said, I think the strangest feeling of all was immediately after getting them off. Something changes suddenly like that, you will feel strange the first week or so when you try and put the mouthpiece on the embouchure and find it's not where you thought it was anymore.
You seem conscientious and devoted to it though, so my advice would be to not worry (or even entertain) the idea of failing. Audition for the group (assuming you haven't already) then practice (carefully at first, while you are readjusting to not having them on) and I'm sure you will do fine.

Trumpet and braces


Generating a new SITE_KEY

Question: One of my clients' webhosts posted the SITE_KEY of their site on a publicly accessible webpage.  How do I generate a new SITE_KEY with the same random process that generated the original?
Comment: Next: [What will happen when I change the SITE_KEY?](http://civicrm.stackexchange.com/questions/3250/what-are-the-implications-of-changing-the-site-key)
Answer: Any source of unknown data should be fine - I'd use a command like this just because it's quicker:
head -n 1000 /dev/urandom | md5sum

Comment: NB: "it's quicker" isn't great criteria for cryptographic RNG - but I do think this will give you a very hard to predict key
Answer: There is no requirement to generate the SITE_KEY in the same way. (In fact, the algorithm changed in v4.6.3.) Rather, follow these requirements:

Stick to alphanumerics
Provide decent entropy (I think 90 bits would be decent, but there's no downside to going higher)

For some better ways to generate a SITE_KEY:

On Debian/Ubuntu-based systems, run: sudo apt-get install makepasswd && makepasswd  --chars=32 (~190 bits)
Use mkpasswd.php from civicrm-buildkit, eg: mkpasswd.php 32 (~190 bits)
Do something closer to v4.6's algorithm: php -r 'echo md5(rand() . mt_rand() . rand() . uniqid("", TRUE) . "www.example.org") . "\n";' (~128 bits)

Random Tip: If you use an authenticated SMTP service for mail delivery and you change the SITE_KEY, then you may need to re-enter the SMTP password.

Generating a new SITE_KEY


Are Old and Middle English questions really on-topic?

Question: I asked a question recently (Send, sent; end, *ent?), which hasn't yet received a straight answer. It leads me to wonder if questions about Old and Middle English are actually on-topic for this site; while it's certainly acceptable for answers to draw on historical English to substantiate speculation or elucidate etymology, should questions about non-Modern English be considered off-topic? After all, Old English is a very different language from English as we now know it—is it different enough to warrant separation?
Comment: If the question seems to go beyond the scope of this site, you might want to see if it would be welcome on [Linguistics.se](http://linguistics.stackexchange.com/).
Comment: What about **[Early Modern English](http://en.wikipedia.org/wiki/Early_Modern_English)**? Should we define a cut-off date? Somewhere around the fifteenth of sixteenth century? Maybe the seventeenth? `And in like wise as she said so they
departed, that neither the king nor none of his council were ware of
their departing.`
Answer:
questions about Old and Middle English are on-topic (there is past discussion on the topic)
but that doesn't guarantee that anybody here will have an answer to in OE or ME question
whether they are on-topic currently or not, I don't think they should be considered and made off-topic.
as suggested linguistics.SE is an appropriate alternative that might get the answers you seek.
yes, OE is quite different from Modern English and they are mutually unintelligible.
but Modern English is closer to OE than any other.
why bother with concerns of separation? just ask it here and it will be welcome (but consider ling.SE as an alternative).
Comment: Edited. Unfortunately for the claim that there was previous discussion, I can't find any supporting evidence yet by searching ELU. I search more, but that claim is provisional then.
Answer: While I would get worried if most of the questions on EL&U are about Old or Middle English, it is also true that EL&U is described using the following sentence:

The English Language and Usage Stack Exchange is for linguists, etymologists, and (serious) English language enthusiasts.

The description doesn't talk of Old English, Middle English, or Modern English. What limits the questions asked on EL&U is the other sentence reported in the FAQ:

You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.

This means, for example, that I should not read Beowulf just to be able to ask questions on EL&U.
We should also consider that some Old English (or Middle English) words are still used nowadays in specific contexts, or in some dialects; for example, thou and thee are reported by the NOAD to be dialectal words for you.
Clearly, when it is possible to answer the question simply reading a dictionary, then the question should be probably closed as "general reference" (which was just added only recently, considering that the public beta phase of EL&U started on August 2010).
I don't think questions on Old English are a problem: Looking at the questions asked until now on EL&U, the questions are about the quotidian usage of the language.
Answer: I'm posting my position as an answer because I don't agree with the only other one.
Like OP, I'm happy for Old and Middle English to be referenced in answers where the etymology and history of words are relevant. But I don't want questions asking what some expression in Beowulf or the Canterbury Tales means. To me, questions about Old/Middle English are off-topic.
The language of those times isn't exactly dead in the same way as Latin, but it's largely unintelligible to Modern English speakers. EL&U is all about how we speak and write today and tomorrow. If people specifically want to learn about earlier forms, they need their own site (unless linguistics.se wants such stuff, which I doubt).
Comment: Yeah, Linguistics isn't necessarily the best forum for the sort of question I have in mind. Thing is, I don't think there's nearly enough desire out there for an Old English SE site either, so I guess perhaps OE and ME questions remain in a necessary grey area.
Comment: @Jon: I don't have a problem with your *send/sent* question. I've no doubt there are one or more actual *reasons* why some verb forms changed in ways that others didn't. But most likely it's complex, not generally agreed, and/or unknown/little known. Almost certainly that information is of little practical use to speakers of modern English, so it doesn't bother me that the question hasn't been as fully answered as it might be. EL&U is just a Q&A forum, not a heavy-duty academic research site.
Comment: Good point. OE is a bit deader than Latin.
Comment: I'm with FF. I suppose I could live with it as long as such questions use their `Middle-English` and `Old-English` tags, but IMHO they are so far removed from modern English that they are different languages. However, the question in ...er... question only got into Old English as a way of postulating how modern English got the way it is. That seems completely on topic to me.
Comment: @Mari-LouA, ivanhoescott: I think the issue here turns on exactly how one defines On/Off Topic. I said *"**To me,** [blah blah]"* in my answer because I *personally* don't want to see ELU devote significant attention to elements of English so obsolete they're largely unknown and irrelevant to current usage. Not everyone agrees with my position (I have 4 downvotes as well as 7 upvotes here). I knew that would be the case when I posted the answer, as implied by its first sentence. We have *opinions* on such matters - no-one is objectively "RIGHT/WRONG".
Comment: @Jon Purdy: why do you feel Linguistics wouldn't be a good fit for these questions?  A question about OE/ME literature, I would agree isn't linguistics; but your *send/sent* question seems absolutely on-topic as linguistics to me!
Comment: @FumbleFingers "EL&U is all about how we speak and write today and tomorrow."
The **Help** does not say say so:
English Language & Usage Stack Exchange is a question and answer site
for **linguists**, etymologists, and serious English language enthusiasts.
Comment: @ivanhoescott FF says **I'm happy for Old and Middle English to be referenced in answers where the etymology and history of words are relevant.** Three years ago he was not excluding any questions concerning OEng, and MEng.
Comment: @ivanhoescott I was sympathetic to your "uneasiness" about asking "Old/Middle English" questions on ELU, and certainly you were not asking about the meaning of the Hamlet text but you are now attacking FF  when you clearly stated that your Meta question was unrelated to him. I think it's a great pity that  questions about the great English literary works seem to be largely ignored by the community. If we limit ourselves by saying that low view counts are indicative to the *interestingness* of a question, we might as well do away with 85% (and I'm being generous) of all questions.
Comment: @Mari-LouA I'm not personally atacking FF. I'm just saying a logically obvious matter.
A linguistic question on English is very on-topic.
And linguistics does study archaic languages.
Comment: @ivanhoescott you've left three comments. The last one was clearly meant to sting "I think you have a wrong idea about this forum." You're talking to a user who's been on EL&U for over three years! In that amount of time, he's got a pretty good idea, and FF is free to express his opinion, too.
Comment: @FumbleFingers Do you agree with that this is a question and answer site for **linguists**, etymologists,
and serious English language enthusiasts?


In ancient Egypt what did the Ba and the Ka represent?

Question: In ancient Egypt what did the Ba and the Ka represent? They were parts of the soul but why two parts?
Answer: The ka is like the spirit; its the element that makes something alive. In contrast, the ba is more like the personality of a person.

The Ka was the life force, astral double or spiritual twin ... the Ba was the impersonal life force of the soul, the essence of one's individuality and unique characteristics.
 - Ruiz, Ana. The spirit of ancient Egypt. Algora Publishing, 2001.

There were in fact five parts to the Egyptian view of the soul, not just two.
Comment: And this spirit of life *and* a soul view predominates in Christian theology today. The so called [tripartite view of man](http://en.wikipedia.org/wiki/Tripartite_%28theology%29), where the third part is the body.
Answer: KA being life force, from the Sun (Ra), and BA being the pattern of personality.  The union of these was, according to scholars, the AKH.
Answer:
"Nor did Mythology spring from fifty or a hundred different sources,
  as frequently assumed. It is one as a system of representation, one as
  a mould of thought, one as a mode of expression, and all its great
  primordial types are virtually universal"

Gerard Massey

The interpretation and translation is based on Wiesław Bator's, scholarly work Religion of Ancient Egypt: Perspectives from Religious Studies (Jagiellonian University Publications: Cracow, 2012)
Three directive souls: Akh, Ba, Ka
Three Intermediary energies: Ran, Jab (Hati), Shut (Khaibit)
Three executive elements: Sekhem, Sanhu, Nacht (Sat)
Akh (bright, illumined) directs the whole intellectual sphere of a human being, and contains all his or hers intellectual potential (that may be trained). The hieroglyphic determinative and logogram of the concept Akh was the walking bird. This element returned to Yaaru (heavens) considered the house of Gods and Goddesses, it was this element that was the 'messenger' of the Gods that worked in accord with the laws of Maat, Akh of the deceased was identified with Stars across the universe, because Akh was also the source of all wisdom, the living wrote letters 'to the stars' or to the Akh of their ancestors, leaving them in their graves, where the statue (tut) of the deceased was erected, they awaited the reply in their dreams.
Ran/Ren (the name), nefer, it meant "beautiful"; "happy"; "joyful"; "glorious"; "splendid". It was the mirroring of the universal creative word (kheru, medu), the name was considered a natural link in-between creative soul and Akh and its passive executive form (Sekhem), but also an inter-mediary element between the Necher (Gods and Goddesses) and affective-emotional domain of the being, called "hhekau" (represented in case of human being by triad: Ba, Yab, Sahh). Name, understood in such a way, was associated with all governing forces over energy, and thus the physical world. The power of the name Ren depends on the quality of Akh of its beholder;
Sekhem was considered the primal, unspoiled form of a human being — the ideal prototype of his body residing in the divine sphere of Nerchru. Visually, Sekhem reminded of earthly body, but it did not have any defects, nor did it undergo the effects of time. Observing representation of phenomena of time-less youth in artistic impressions conjured by Egyptian masters of Sekhem of immortal beings, as they were considered artistic ideations of the Earthly mirroring of Sekhem. This kind of idealistic portrayals were considered earthly mirroring of Sekhem and they were given the name Tut, which were included by some researchers into the fundamental elements of one's personality. Egyptians did not deny tut (the figure) a form of "life" (Tut Ankh or "living image"), but always considered Tut an Earthly substitute of Sekhem. Many researchers sought in Sekhem some active force, working in an autonomous manner, which might not be completely accurate, because the same element was equal in a determinative of a standing mummy, which may be found amongst the concepts of other bodies: Sahh and Djet. Thus, all three elements of human nature belong to the same category of receptive, or passive forms. This hypothesis is supported by Egyptian mythology, that the Goddess Sekhmet, of personified Sekhem of the highest being, is seen as a passive executor of the will of the King of Gods — Atum-Re-Chepri, who, according to the Stone of Shabaka, is understood as the "heart" and "word" of the panenteistic God Ptah; The above-mentioned elements of the human personality which work in the divine sphere of Necheru were considered the most perfect prototype of a mortal, thus the numinous mirroring of his Earthly nature.
The next triad of the elements of a human being are: Ba, Yab, and Sahh, which belong to the inter-mediating sphere of the whole being. Here, all weight of afterlife of a human being rests, because it is them that determinate what will one do living one's life, and what was the intention of his doings. Thus, they are the main protagonists of the judgment over the dead, because they are responsible for a human beings conscious actions and submit to the judgment over the dead. They are as follows:
Ba: This element is most closely associated with the understanding of a 'soul' in the Western occidental civilization. Ba may be the reflexive, passionate element, responsible for life choices. Egyptians held that Ba was a loyal servant, thus a soul of one was his loyal servant (bak). Ba is described in writing by two different determinatives: the older one is a black stork, the younger one falcon with a human head. The reflexive soul was thus considered an inseparable companion, which suggests motives and way of acting. Ba was not responsible for creative thought, but advised how they should be applied, it resided in the "heart" (yab), and its inclinations influenced the active heart (Hati). The heart commanding separate senses and movements decided which of the Ba-influences to execute, and which one should be rejected. When Ba is recommending inner tranquillity, moderation, care for oneself and others, or it "persuades Maat", then it has a chance of attaining the state of divinity and it awaits a reward in the afterlife. This happy fate met him/her only when they conducted themselves as above. When the Ba-soul contradicted the order of Maat and influenced the human being to act against his con-science (co-feeling), or the voice of the Yab-heart which was inscribed with unfaltering laws and principles stemming from Ren in the Necheru sphere — then it must have been punished with other elements of the deceased, belonging to the sphere Hhekau, dying in cruel condition in the Underworld; The advices of the soul might be completely contradicting con-science, and even may put afterlife in doubt, in the scripture 'Conversation of a suicide with his Ba" we may note a complete contradiction between the Ba-element and inner consideration of a man. The soul or Ba in this case seem to be a synonym of sobriety and at all costs it attempts to silence the burdened con-science. The Ba, attached to all pleasantries of life conjures its image and recommends idleness. Operating on rational arguments the Ba negates afterlife, just to protect the protagonist from suicide. It knows that it leads to the extermination of consciousness in the afterlife. To the life in opposition to Maat it portrays a noble death, which is saving from wickedness and assures existence in the afterlife. The con-science suggests that a person living in accord with Maat has more influence in the world than the living body, attaining a degree of post-mortem divinity and the ability to conjure miracles. In the light of Egyptian narrative, the Ba is not only belonging to the human existence, also Gods and animals possess it. Yet, Gods are not limited to having just one Ba as the 'rational friend', the Ba may undergo transformations. Of course, a Ba belonging to a Deity is of much higher hierarchy than that of a mortal or an animal, it is higher, perfect, and infallible. In essence, the Deity-Ba is similar to human Akh, Ba of the divine is a manifestation of Necheru, may inhabit the bodies of many animals and this fact is the basis of Egyptian zoolatry (for example the Deity Horus, as the God of Life, may be emanating through all living beings in the positive aspect of their expression).
Yab/Hati, or 'heart' is the main concept of Egyptian anthropology and the key to the active human being, Egyptians believed that that it is the 'temple and store-house' of thoughts, and thus they assigned it a role similar to this that we are assigned to the brain nowadays (it might be said that the brain and associated cognitive processes and affective states and feelings are modulating the essential heart, thus experiences, and pain, suffering, influences or cleanses the heart alike to karmic inclinations, when a heart 'drowns' in its despair, or becomes alike to stone — different from detached abiding — it grows cold — but it may not be limited to biochemical physiological brain functions, it works with the components that give the feeling component authenticity, and the genius its proper, spiritual function, thus also it might be said that apart from a regular heart pumping blood through the organism, there is a hidden layer, a spiritual heart and its circulation, through which all states of being are carried throughout thus some believed that in blood therein is also contained the vital force of the 'heart', it is a violation thus to abuse the blood of one's 'heart', as it develops a parasitical dependence, and reliance on someone else's 'heart' thus rejecting one's own as an independent being). The heart was divided into the passive form (con-science) called yab, and directive active part (desire, or rather — direction) — hati. As "con-science" the heart (yab) is never bribed and it may be a witness against the deceased in the world of the dead. Some researchers believed that "yab" is directed towards the meta-physical worlds, while hati directs the doing of a human being in the world of the senses, for "hatia" means also "ruler". It thus also has in Egyptian texts a function alike to defence-double (ka) controlling the visible physical body. According to Egyptians they are different in the sense that "hati" is guided by conscious working of our body, and Ka controls only the physiological functioning of our organism that is not guided by our will (in essence Yogins of the East, by establishing Hati-Hatia command over Ka, they could be in charge of the emotional, affective, cognitive and other functions of the mind and body, thus establishing a seat of consciousness linking it with the 'true will' or the higher image). The "hati" heart, as a collection of active desires, emotions, also commands the passive form ("body") related to the sphere of Hhekau, also called Sahh
Sahh: is a passive being of the human being, which is at disposal of the heart and executed through the meditation of the Sahh(-body) the will of the Ba-soul. It works without the interference of the senses and as a signal to act it is enough to think (emanate or vibrate) a "word" (any directed thought-form, or act, voice etc.). It may be called "soul-body", "subtle-body", or "emotional body". Because its determinative is also a standing mummy, a corpse, it is said the true process of mummification was an attempt at turning a regular body into Sahh (perhaps an astral double). These concepts, however, are not identical because the mummy is described with the Egyptian word "Ui" although equipped with identical determinative. In any case Sahh was the principle tool (and perhaps a protective carrier-shielding) in working of the Ba-soul through mediation of the heart, and it could take any shapes and infiltrate physical matter. It could also shape it into proper, visible imaginations; It is her that could morph its being into notions, or representations of Deities (modern idea of 'godforms', 'masks' or 'illusions', unlike true Deities), animals, plants, and symbols. It could also change things into another (transmutation, for example modifications on the mental-astral plane, or endowing physical objects with various kinds of energy — consecrated, or 'cursed' objects). That is why Sahh was an element, without which no magical work could be performed, that was considered obvious and common.
The third sphere of the world, in which a human being played was the physical world, called nachtu. There are three functional elements here: directing — Ka, intermediary (Khaibit, Shu) and executive (Djet), from all listed elements of personality only the last one is captured in a sensual way, khaibit (shadow-being) is a delicate substance, and Ka is considered an invisible care-taker sustaining the human body in a good condition.
Ka — It is not commonly agreed, but some speculate that it is closest to the form close to 'platonic ideas', others that it is a blind instinctual force without any form of spirituality (it might happen that in fact it is blind, instinctual at first, but undergoes refinement into the divine, numinous 'ideas' that penetrate this world as interpretable powers, or eternal grammar of the world, which understood, becomes reflected in it). The main function of Ka is providing nourishment to the physical body. The female version of Ka, or Hemsut proves that this component has a role in sexual differences and regulated physiological needs. Ka has also some relation with the ancestors and heritability, Ka might look like a double (perhaps an astral double, representing the image of the person at a given time). Ka most likely was not responsible for psychic and moral traits of a human being. The energy-basis which Ka operates in, governing the physiology of a human being is khaibit (shut). After death, Ka resided (with two other elements) in the grave, still having physical needs.
Khaibit (shut), or "shadow" was considered amongst the Egyptian thinkers an intermediary element that transports the recommendations of Ka to autonomous physiological systems. It was always portrayed as pitch-black, and that's why it was called the 'shadow'. This shadow-soul accompanied a human being even at night, being his visual representation of vital and reproductive forces (thus shadow-substance may be considered as a psycho-sexual energy in relation to living organisms). As a state of physical reality, mediating between pure energy and matter may be often "borrowed" by Sahh, which in such a way is materializing and assumes a visible form. After death, Khaibit lived in the grave altogether with Ka and Djet, and like them, required nourishment.
Djet: One of the many names of the physical body. In Egyptian texts there are several synonyms: "kat, sat, hha". As the most sensuous of them all and the only fully accessible sensuous element that played a major function. The most important function of Djet was to execute the commands of "heart" or hati. In such a way the physical body realised in the world ideas of purely conceptual element — Akh descending from the divine sphere of Netcheru and through Djet the effects of conscious choice of man and his decisions which he makes in the sphere of hhekau. No wonder that caring for the body was a fundamental responsibility for every Egyptian, moreover aversion towards ascesis was on par with aversion to lack of moderation in submitting to physical lusts. Both stances led, according to Egyptian wise-man to the destruction of an organism, and thus criminally limited the potential acting of the Ba-soul and divine particle Akh in the physical world. After death, Djet was transformed into a ui-mummy for Khaibit and Ka to live further;
Comment: Please do not copy paste without giving credit to the original owner
Comment: The interpretation and translation is based on Wiesław Bator's, scholarly work Religion of Ancient Egypt: The rest is my own research.


What Motorola Bar Code Scanner Development Options are there?

Question: I have been asked to investigate the possibility of developing software for a Motorola bar code scanner. From my initial searches it would appear that the only options are to code 'from the ground up' using Visual Studio or to use MCL-Designer, a RAD tool. Is this the case or are there other RAD tools available?
The project is really very simple & I'm surprised it is not something that is available out of the box on the scanner (maybe it is, I am open to correction). All that needs to be done is for the scanner to pick up a CSV file containing code to text translations (so that the person doing the scanning can confirm the device has scanned the correct code), keep a list of the codes scanned and associated quantities, then, when the session is complete, download the list to a PC. As I've said, if this application is already available then someone pointing me in the right direction to a datasheet or similar would be appreciated.
Comment: I'm also looking into something similar.  Did you ever find an answer to this?
Comment: @anon. Sorry, no, the project did not happen in the end so I did not go any further.
Answer: You should be able to configure your scanner to use USB HID (POS) instead of USB HID (Keyboard) by simply scanning a barcode settings from the manual for the device. Then download and play with the sample project from http://www.codeproject.com/Articles/18099/A-USB-HID-Component-for-C.


changing toilet seat on wall mounted toilet

Question: I can access the screws underneath the toilet but they are placed horizontally like as if they are screws holding the toilet bowl to the wall instead of downward facing screws holding a toilet seat to the bowl. Does this look right to anyone? How best to proceed?
Any advice/reassurance welcome
Dash
Answer: Look at this video starting at about 11 min 30 s. Grohe wall mounted toilet
EDIT I see a screw exposed under the swing away cover in the picture posted. I would assume that unscrewing it would release the fitting holding the seat.
It might be wise to consult the landlord even before a seemingly simple change of a toilet seat. Maybe his staff  know how to do this and would do it for you.
EDIT2 Have you looked or felt under the bowl to see if seat bolts are visible? See What kind of tool do I need to access this bolt?
Answer: Those horizontal studs and nuts / washers do hold the toilet to the wall.
The seat fixings are too far back to have an easily accessible fixing from below.
You might find that you will have to take the toilet off the wall as the seat hinges are fixed through the porcelain and usually just start rotating once they are loose, at least that has been my experience.
Comment: Thank you Solar Mike! I think I'll leave this one to the landlord :)
Comment: I have no experience in this, but it is hard to believe that the toilet would have to be removed from the wall to replace the seat. Are you sure there is not some clever system to release the seat?
Comment: @JimStewart not the ones I have seen, but if you have come across others you are welcome to post.
Comment: Have you looked up past the large bolts with a mirror and flashlight?
Answer: Do NOT touch the horizontal bolts/nuts.
It looks like the Duravit starck 3 wall mtb wc.  You can view the different versions of the Starck 3 toilets with specs to clearly identify the model you have.  At www.duravit.us. To determine which you have ,Measure from the wall forward along the top.
It looks like you'll need their most common toilet seat is a Duravit 0063390000.  It's the slow  close version.
Keep in mind that there are 3-4 models of the starck 3 bowl, and each gets a different seat/cover, in slow close and non slow close.
Keep in mind that Duravit is a premium-luxury fixture brand which is not really geared towards "diy" customers.


How can I handle a child that claims medical problems as a bad excuse?

Question: I have 3 kids who seem to use medical reasons for excuses, most often to not go to bed. For instance, my 7 year old periodically "Can't move" at bed time to get to his bed, but when he gets in there, he suddenly is able to move out of his room. I'm not sure quite what to do about it. On the one hand, I feel like giving him attention because of a fake illness is a very bad thing, but on the other hand, a part of me wonders if it really is something. What can I do? Thanks!
Comment: Well, I don't really know, but I would more or less ignore it. Especially I wouldn't let the excuse work. If their excuses doesn't work they probably stop using them, right?
Answer: Our son sometimes became "ill" to avoid going to school. When this behavior started becoming a habit, we dealt with this challenge by acting just as if he WAS sick for the rest of the day.
He was allowed to stay home, but was reminded that people that are sick must rest to get better. Therefore, he was confined to bed or couch and unable to participate with the other family activities or exert himself with play or other pleasures all day. Television or gaming was not allowed because he needed to rest his eyes and body. Meals were bland soup instead of some yummy favorite the rest of the family got, because sick people need special diets.
If illness was not validated, the imposed rest and limited diet resulted in a quick recovery; however, the "bitter pill" of restrictions remained in place fall longer than the spontaneous recovery "just to be sure" all is well.
There was rarely a need to repeat this "lesson" when reminded of what we do to help our loved ones recover!
Comment: Parents are conniving sneaky bastards
Comment: @DVK Probably because we got lots of practice as kids outsmarting our parents. :P
Comment: @DVK Parents _should be_ conniving sneaky bastards.
Answer: Assuming of course there is no real medical problem, it is either playful, or it is defiant.  Decide which it is, and treat is as such.
If it is playful, and you have time, play along. If it is playful and you don't have time, or when you are done playing, say so. Then, continued refusal is defiance.
For defiance, you need to respond to it as you would other direct refusal to do what is told or what they know is expected. Substitute "NO! YOU CAN'T MAKE ME" for "I can't move", and act accordingly. My wife and I were never ones to tolerate direct defiance, so we would act swiftly and harshly. We would do something like pull her off the couch, drag her to her room, and leave her there with a valued possession in my hand.
Answer: If you think that the kid is giving you a hard time with a fake "medical problem", then ignore him. He'll figure out after a little while that you aren't falling for it, and that'll be the end of that.
When a child who frequently pretends to be sick or injured actually is sick or injured, he'll find a way to tell you that he's not faking. Don't worry about it.
Answer: Call a hospital and ask for a nurse who is in contact with terminally ill patients. Tell her your child thinks being sick makes its life easier, and ask if you can come visit. Perhaps she will let you. At most I expect she will give you 5 minutes of her time, during which she can explain how much it sucks to be dying from an arbitrary illness.
She may know a few old timers who want to do a good deed before they pass into the great beyond. It would be wonderfully constructive if they could scare your child into not being quite so whiny.


Is there an app embedding the Flash player?

Question: Is there an app embedding the Flash player? I don't want to install the flash player in osx. I just want to use this app when I need it. Does it exist?
Answer: Google Chrome comes with its own instance of Flash that runs only when it needs it and only within the scope of Chrome. I have uninstalled Flash from all my Macs and simply turn to Chrome when I really need Flash for something.
Answer: Google chrome both includes and updates it's own Flash plugin.  You can also setup a command key shortcut for opening your current safari page into Chrome for the instances when you actually need Flash.  See here for more info.


How to cancel a valid Schengen visa and apply for a new visa?

Question: I have a valid Schengen multiple-entry business visa valid for one year, from 6 September 2015 to 5 September 2016. I traveled to Germany from 6 September 2015 to 31 October 2015, for 54 days. I need to travel again from 10 January 2016 to 02 April 2016, for 84 days. With this visa I cannot travel as the duration of stay is more than 90 days within 180 days. Can I cancel this visa and apply for a new visa? What is the process for this?
Comment: Can I suggest not giving dates as number/number/year as they mean different things in different parts of the world. Writing the month name avoids confusion.
Comment: Do check the calendar, I think there are only a few days missing, this trip might be possible on your current visa if you shave a week or two at either end or even in the middle (short trip back home, to the UK or elsewhere?).
Comment: I checked with the [calculator](http://ec.europa.eu/dgs/home-affairs/what-we-do/policies/borders-and-visas/border-crossing/schengen_calculator_en.html), it seems that if you enter on January 10, you only have 34 days of stay left. But if you enter on January 30 or any day after that, you have the full 90 days again. Leaving for 21 days at any point during your stay would also make you able to return and stay until April the 2nd.
Comment: phoog posted as a comment below the best answer. " you will need to get a type D long-stay visa, or else change your travel plans." Actually, the question is pointless. You can't just tweak a visa into another type or reset it, you'll need a different one.
Comment: @Relaxed , Could you please help in how to use the calculator "http://ec.europa.eu/dgs/home-affairs/what-we-do/policies/borders-and-visas/border-crossing/schengen_calculator_en.html" as I could get the 90 days stay even if entering 30 Jan 2016. Many thanks .
Comment: @suvendubishoyi That seems correct, what if you enter January 29?
Comment: @Relaxed entering 29 january will be also fine , but need 90 days in one go ,
Comment: @suvendubishoyi OK, but what do you see when you try January 29 with the calendar?
Comment: @Relaxed , could you please tell me what date I should entry with Date of entry/Control .
Comment: @suvendubishoyi You enter the date on which you wish to enter and the calculator tells you how long you may stay, based on the previous stays you entered in the table down below.
Answer: The 90 day period is a computed on a rolling basis and hence, as other posters have mentioned, you cannot circumvent this by applying for a new visa.
Schengen C visas are specifically for short stays and you are NOT allowed to work but only conduct business meetings, discussions, trainings etc.
Since you are staying for long continuous periods, there may also be a question on your real intention vis-a-vis the intent of the C visa.
Comment: (+1) Excellent point! The duration of stay is not the most pressing problem in this case.
Answer: Obtaining a new Schengen type C visa does not change anything to the 90-day-in-any-180-days limit as it also applies across several visas. A new visa does not open any fresh rights to stay in the Schengen area above the 90-day threshold.
If your intended stay is longer than allowed under this rule, any visa application should be refused for this reason alone. So cancelling your current visa and applying for a new one is pointless.
The only solution is to secure another type of visa/permit from Germany. I don't know how realistic this would be in your situation but those are entirely separate from Schengen visas and cancelling your current visa is therefore in any case unnecessary.
Should you ever want to have a Schengen visa cancelled, you can ask the consulate that issued it (or perhaps another one) to revoke it, the Schengen visa code provides for that. But, again, it would not solve your problem in this case.
Comment: @suvendubishoyi YOU CAN'T. It's forbidden, that's what the 90-day limit is about, you already used most of that, you have to stay out of the Schengen area for some time or use something else than a type C visa. For the rest, please refer to my answer, asking the same question over and over won't change the rules.
Comment: @suvendubishoyi No, not a Schengen short-stay visa. A German long-stay visa, maybe, you would need to ask the German consulate about that but I would not hold my breath (that's what I allude to in the third paragraph). There is no easy fix, the regulations are specifically intended to prevent what you want to do. Look at it this way: Come April 2, you would have stayed almost 5 of the last 6 months in Germany, that's not a short visit anymore, you are practically becoming a resident.
Comment: @suvendubishoyi you will need to get a type D long-stay visa, or else change your travel plans.
Comment: Kindly suggest can I apply for a new visa without canceling the existing visa .
Comment: Please suggest how to go for 3 months with Schengen business visa: category C.
Answer:
If you are working for a German company, you may qualify for a "blue card" work visa. This requires a job with a salary of 48400 Euro per year (or less in some fields).
If you are self-employed, you can get a work visa if the business plan is credible and if positive effects for the German economy can be expected.


Are we obligated to apologize to gentiles?

Question: A friend of mine told me we don't have the obligation to apologize to a gentiles. Is this true?
Comment: Do we ever have an obligation to apologize to Jews? What obligation are you referring to?
Comment: Inversely related (teshuva when a gentile wrongs a Jew): http://judaism.stackexchange.com/q/45798/472
Comment: News to me. If I didn't apologize to Gentiles, I wouldn't be here writing this. Curious - does your friend live in a shtetl? If not, does he apologize to Gentiles? If he does, isn't he lying to himself?
Comment: @DanF He is not lying to himself, just like I'm not lying to myself when I tell myself I have no obligation to eat noodles for lunch today.
Comment: @DoubleAA Perhaps your commute and your work is gentler than mine. Remember, you asked "what KIND" of obligation. W/o that clarity, I'm assuming that we have an obligation to keep ourselves alive and uninjured by Gentile "wolves" who make a huge deal if we don't apologize to them.
Answer:
הֱוֵי מִתַּלְמִידָיו שֶׁל אַהֲרֹן, אוֹהֵב שָׁלוֹם וְרוֹדֵף שָׁלוֹם,
אוֹהֵב אֶת הַבְּרִיּוֹת וּמְקָרְבָן לַתּוֹרָה
Be of the students of
Aaron: Loving peace and pursuing peace, loving all people and bringing
them close to the Torah.

(Tractate Avot 1:12)
In fact, in addition to the basic human decency requirements, there are the additional issues of besmirching the people and G-d you represent by association (chilul hashem) as well as the problems associated with inciting antisemitism.
Comment: Where does "all" people emanate from this translation? This seems contradictory, because it seems that would imply that we have to bring all people, including Gentiles closer to the Torah, as well. Does that mean that we should teach them Torah, and that's am obligation, as well? The "chilul hashem" idea does not appear to emanate form the Pirkei Avot verse, at all. That's an issue of how we behave in general towards each other as well as gentiles and has nothing to do with apologizing. What does this answer have to do with an obligation to apologize?
Comment: @DanF "אֶת הַבְּרִיּוֹת" doesn't translate well literally in this context into English ("the created"[?]) - but the language is clearly meant to be more inclusive. In fact, the author of the phrase (Hillel) is singled out for his involvement in bringing Gentiles closer to the Torah even where their seemingly disrespectful statements led his colleague (Shamai) to push them away. With regards to your latter point, common sense dictates that apologizing is part of "how we behave in general" as noted by the questioners tag of "derech-eretz-manners" which means it is also related to chilul hashem.
Comment: @DanF I'll be honest, I don't really understand your objection.
Comment: I don't object to the principle, as I feel that it's proper and necessary even to apologize to Gentiles when you have done something wrong (and, sometimes, even if you haven't). I just don't see how the term אֶת הַבְּרִיּוֹת includes Gentiles. Furthermore, the adage mentions nothing about an obligation to apologize to anyone about anything. I see what you said about Hillel, and I agree with that, but I am focusing solely on the text you use and it doesn't seem to provide any direct proof to answer the question.
Comment: @DanF  In Rabbinic literature, briyos is clearly used to refer to all mankind (and sometimes to all living creatures), for example in medrash rabba e.g.:ויהי עשו איש יודע ציד, צד את הבריות בפיו; יקבוהו לאום, זה פרעה שגנז התבואה בשני רעבון והיו הבריות מקללין אותו, ;והיה מלסטם את הבריות, שנא׳ והוא יהיה פרא אדם; or most explicitly: (shemos rabba 20:6) כל הימים שהיו הבריות רואים את ישראל, היו משבחין אותן.ומי היה משבחן?בלעם הרשע, שנאמר מה טובו אהליך יעקב כנחלים נטיו.
בלעם ראה אותן ותמה, פרעה ראה אותם שורות שורות, ...!
לכן נאמר: ויהי בשלח פרעה: http://www.daat.ac.il/daat/tanach/raba2/20.htm etc.
Comment: @DanF (I've never heard of a medrash that said: אתם קרויין בריות)
Comment: Got it, now. Thanks for the education. The Pirkei Avot adage, however, doesn't explicitly state an obligation, though. Offhand, I'm unsure if there is ANYTHING in Pirkei Avot that would imply a direct "command" or mitzvah rather than advice on proper behavior.


Connecting multiple instruments into 2 headphones?

Question: My friend and I are trying to find a way to practice as quietly as possible,because we live in an apartment with lots of people complaining.
So we were wondering if it were possible to connect an electronic drum ,electric guitar and a mic in such a way that we can both listen to what we are playing with each of our headphones.We have the instruments,2 headphones and 2 amps.If this is possible what would be needed?
Thank you for your time.
Comment: You need a mixer and a headphone amp. And a bunch of cables.
Comment: Thank you for your response.So something like http://www.guitarcenter.com/Behringer/MICROAMP-HA400-Headphone-Amp.gc will have the headphones connected,then this amp would be connected to the mixer like http://www.guitarcenter.com/Harbinger/L502-5-Channel-Mixer-with-XLR-Mic-Preamp.gc , which would have the instruments connected to it?
Comment: JamHub. This is precisely the product you want. http://www.jamhub.com/products/
Answer: You have a few options depending on how much you want to spend and how you might use the equipment in the future.
The ideal product that was invented for just the scenario you described is the JamHub Bedroom available at many music specialty stores at a price of $299.99 US.  It allows up to 5 musicians to plug their instruments into one of the 5 stations and dial up the desired mix for each individual instrument or microphone and each musician can plug their own headphone in. There is a picture below and a great description and link to a demo video here JamHub Bedroom at Sweetwater Music

Next best option would be a small mixer with enough inputs to accommodate your guitar, mic and drum kit and either a headphone amp or a headphone splitter.
A mixer like the Harbinger L502 pictured below will accommodate a mic, electronic drum kit and guitar and has a headphone out jack. This mixer is around $45.00 US and a very similar Behringer Xenyx 502 Mixer is about the same price.
Small format mixers with built in effects start at just over $100 US and will give you the option of adding effects such as reverb or delay if desired.  If you get a mixer and hope to start playing in a band someday, you might want to be sure you get one that will accommodate your future needs as a stage mixer in addition to your silent practice solution.

Then you can plug a headphone splitter cable like the ones pictured below (very inexpensive) into the headphone jack to provide headphone monitoring for multiple headphones.  Of course this option does not allow for individual volume control unless you have a headphone with a volume control.

Or for individual volume controls for each headphone, you can use a headphone amplifier like the one below.

Here is one other idea.  If you think you might like to record some of your jam sessions and convert the recordings to mp3 files (perhaps so you can post on social media), you might consider using one of the headphone splitter options with a multi track recorder such as the Boss BR 800 Digital Recorder (I own one of these).  The JamHub (mentioned above) also has a stereo recording output for the overall mix.
The Boss BR 800 pictured below will allow for simultaneous recording and monitoring (through the headphone jack) of up to four inputs. You don't have to be recording to monitor the input.  It also allows you to over dub using up to 8 recording tracks and has tons of built in effects for guitar and vocals.  Similar models by Zoom and Tasco can be found for under $300. US.
Comment: Thank you so much for the incredible response!I really appreciate it.I am probably going to go for the second option,as it seems to be the cheapest.The jamhub seems really nice but it is a little too much for my current budget.Thank you for all your responses.
Answer: To connect multiple headphones to the single output, you need a headphone amplifier. I am using ART Headamp IV but many others exist. You can also try to use one of the available connectors like this that simply forks wires, but the sound level differs if the different headphones are connected in parallel, and cannot be adjusted individually.
To join multiple inputs into the single input for the head amplifier, you would ideally need a mixer. However you mention that you already own as much as two  amplifiers - these frequently have the built-in mixer so that the different sound sources can be connected directly to the amplifier. If it is so, simply plug all sources into one of the amplifiers and connect its linear (preferred) or headphone output the amplifier to the input of the previously mentioned headphone amplifier.
Of course, you need to suppress the regular high power output of the amplifier if using it as a mixer. Look of some switch, maybe on the rear side. Of maybe the speakers will turn off automatically after you plug the (not necessarily used) cable into headphone jack.


Mount and automount and security problems

Question: Are there any security problems related with (auto)mounting device?
Answer: That differs from your setup.
On a private setup (you are accessing your own box) there is no problem. On a company setup (many people are accessing many different boxes from your employer) there are security risks. Just think about USB drives, SD-cards and so on.
For any further answer we need a bit more information.


Can we own a bird pet which will in a cage?

Question: My cousin asked me to get one for her but I said : "Sorry, It's not allowed in Buddhism and we should care for them not in a cage even if cage were made of gold and must set them free and liberate them".
So may I know if it's allowed or not?
Instead of bad karma I felt myself pity and sorrowful for them. I felt so bad for animals if they're in trouble or something like this.
And isn't it same as slavery?
We making it as pet for our entertainment and not for caring for them.
So please guide me.
Answer: So may I know if it's allowed or not?
It's a Buddhist practice, in some countries, to buy caged birds (or sometimes other animals, like fish), in order to liberate them (i.e. to set them free, let them go).
I guess the purpose is to acquire merit, and that an idea behind it is that birds want their freedom.
An "unintended consequence" (of buying birds) is that people trap birds in order to sell them.
For this reason you might (or might not) want to refrain from buying birds, according to the same logic as being vegetarian (i.e. not buying meat in order to not encourage other people to kill animals): as you probably know, different schools of Buddhism hold different views on this subject.
IMO birds are a special category of the topic of, more generally, pet animals. Perhaps some people would keep fish (thinking that fish don't object to being kept); or "domesticated" animals like dogs, cats, cows, chickens, horses...
Buying dogs, incidentally, provides a financial incentive to breeders of dogs (i.e. it causes people to breed dogs). Some people suggest that you shouldn't buy a dog from a breeder, but instead "rescue" a dog from a shelter. When you rescue a dog, by the way, that's to keep the dog rather than to free it -- it appears that a pet dog would prefer to stay with its owner than to have to face the world alone.
Apparently there's an "unintended consequence" of getting dogs from a shelter: I read recently that some shelters are rich (from the donations they receive) and so buy puppies from breeders in order to have more to rescue! A way to avoid that, if it matters, might be to rescue an older dog (not a puppy).
It may be relevant to mention that animals in captivity sometimes live longer than in the wild -- they may be "safer", better fed, better cared for.
And isn't it same as slavery?
I don't know what goes on in the mind of a bird: I suppose they're not aware of slavery as a state-of-self, but are aware of a cage as a barrier-to-liberty.
"Slavery" (as a type of human relationship) would exist in the mind of the "owner".
From a human point of view, a good thing about not being a slave is that you can choose your master or boss (i.e. choose who you work for). If you don't like your current boss, you're at liberty to look for another.
Dogs seem to me more able and willing to communicate than birds. Pet dogs often have an opportunity to escape, and choose not to. The "leash" is often seen as being, and used, only for the dog's safety -- to protect the dog's safety rather than to protect the owner's ownership of the dog. I'm not sure that I see a pet dog as a slave: more of a friend, partner, or family member. OTOH some dogs are kept chained or caged: and it's easier to see them as "slaves".
I guess some people see a pet (dog or bird) as being like a friend or a kind of friend, or like a young child, rather than only like a slave.
Having (and looking after) a bird is a responsibility, which some people would prefer to avoid or to not seek -- if it's true that possessions are a burden, that (being burdensome) may be even more true of live animals -- but maybe that (whether it's seen as a burden or a blessing) depends on the attitude of the person.
Comment: Thank you. I'm agree with you but I think what would animal  felt like. I think about them as if what's on their mind cause they're helpless. Even if I want a bird pet then I won't put it in a cage so it can live freely whether would live with me or will fly in forest. Thank you for your invaluable time.
Answer: According to the preaching of Lord Buddha, before you kill or hurt animals/humans think it is you (do you like if someone kills/hurts you?)
Definitely answer will be no. So you can apply the same theory to your problem. If you were that bird in that cage, do you like to stay rest of your life in a cage?       Answer yourself to this question and you will get the answer you need and act accordingly(I told this with having the idea of answer being a "NO")
Comment: yes I thinking same what bird would felt like. And as if Buddha told us we must have compassion towards animals that don't let me do such things. I'm keep  trying to teaching Dhamma to my family. Thank you.
Comment: Good luck with your effort and it's really good what you are trying to do. Never give up on them
Answer: I don't know the customs of Buddhism, but there is a saying that I'm twisting a little that I find to be a useful guide ... if you set an animal free and it comes back, it wants to be with you. Some birds do in fact like the people they live with and seek their company.  My dog would always stay with me, but even if she wandered off, she would come back to me. Same with the cat. I also believe that adopting / rescuing a pet is the most humane and good thing to do.
Answer: If you have owned a pet bird before, you will understand the fact that birds cannot be enslaved in any ways. You can only tame a bird, not enslave.


Get a list of all files in folder and sub-folder in a file

Question: How do I get a list of all files in a folder, including all the files within all the subfolders and put the output in a file?
Answer: You can do this on command line, using the -R switch (recursive) and then piping the output to a file thus:
ls -R > filename1

this will make a file called filename1 in the current directory, containing a full directory listing of the current directory and all of the sub-directories under it.
You can list directories other than the current one by specifying the full path eg:
ls -R /var > filename2

will list everything in and under /var and put the results in a file in the current directory called filename2.  This works on directories owned by another user including root as long as you have read access for the directories.
You can also list directories you don't have access to such as /root with the use of the sudo command.  eg:
sudo ls -R /root > filename3

Would list everything in /root, putting the results in a file called filename3 in the current directory.  Since most Ubuntu systems have nothing in this directory filename3 will not contain anything, but it would work if it did.
Comment: Maybe telling the person to cd into the directory first could be added to answer.Also this works fine if i own the directory but if trying in a directory say owned by root it didnt.I got the usual permission denied and sudo followed by your command also gave permission denied. IS there a work around without logging in as root?
Comment: Well I did say "current" directory.  The correct use of CD might the subject of another question, and I'm sure it has been.  You can list directories owned by root as long as you have read access to them.  Directories owned by root to which the user has read access _can_ be listed with ls -R.  It's hard to imagine why you'd want to list directories owned by root to which you don't have read access, but sudo does indeed work if you give the full path.  I'm adding examples for both of these, but excluding the use of CD.
Answer: Just use the find command with the directory name. For example to see the files and all files within folders in your home directory, use
find ~

Check the find manual manpage for the find command
Also check find GNU info page by using info find command in a terminal.
Comment: This is the most powerful approach. `find` has many parameters to customize output format and file selection.
Comment: That's the best approach in my opinion. Simple and practical. Could also do `$ find . > output` if there's many directories.
Answer: tree
An alternative to recursive ls is the command line tool tree that comes with quite a lot of options to customize the format of the output diplayed. See the manpage for tree for all options.
Answer: Also:
gvfs-tree /path/to/folder/

will give you the same as tree using other characters for the lines.
tree -a

to display hidden files too
tree -i

to not display lines
Answer: You could also use the GUI counterpart to Takkat's tree suggestion which is Baobab. It is used to view folders and subfolders, often for the purpose of analysing disk usage. You may have it installed already if you are using a GNOME desktop (it is often called disk usage analyser).
sudo apt-get install baobab

You can select a folder and also view all its subfolders, while also getting the sizes of the folders and their contents as the screenshot below shows. You just click the small down arrow to view a subfolder within a folder. It is very useful for gaining a quick insight into what you've got in your folders and can produce viewable lists, but at the present moment it cannot export them to file. It has been requested as a feature, however, at Launchpad. You can even use it to view the root filesystem if you use gksudo baobab.
(You can also get a list of files with their sizes by using ls -shR ~/myfolder and then export that to file.)
Comment: The OP wanted the results in a file, presumably to do something else with it.  While Baobab is a good tool, it doesn't seem to meet the requirements of the OP's original question.
Comment: @fabricator4 I also added the ls option, as baobab cannot currently output a list.
Answer:
Go to the folder you want to get a content list from.
Select the files you want in your list (Ctrl + A if you want the entire folder).
Copy the content with Ctrl + C.
Open gedit and paste the content using Ctrl + V. It will be pasted as a list and you can then save the file.

This method will not include subfolder, content though.
Answer: List all files, first level folders, and their contents
ls * -r
List all first-level subdirectories and files
file */*
Save file list to text

file */* *>> ../files.txt
file */* -r *>> ../files-recursive.txt

Get everything

find . -type f

Save everything to file*

find . -type f > ../files-all.txt


Which came first, the natural logarithm or the base of the natural logarithm?

Question: The natural logarithm function ($\ln x$) and the base of the natural logarithm function ($e$) are both extremely useful. They're also both closely related: $\ln (e^x)=x$, and $e^{\ln x}=x$. But which came first? I would think it's likely they were developed together, but each could have been developed separately. For example, $\int 1/x \,dx=\ln x$, and the $\cosh$ function can be described in terms of $e$. So which came first: the natural logarithm function or the base of the natural logarithm function?
Comment: James Whitbread Lee Glaisher's historical survey paper *On early tables of logarithms and the early history of logarithms* [**Quarterly Journal of Mathematics (Oxford)** (1) 48 (1920), 151-192] is very informative, but it doesn't seem to be freely available on the internet.
Answer: It may seem strange but logarithms were invented much earlier.
Napier used the base $(1-10^{-7})^{10^7}$ which is very close to 1/$e$ (within 0.00000002 of 1/$e$).
Number $e$ (as a limit) was formally defined by Euler approximately 100 years after
Napier.
Napier's MIRIFICI LOGARITHMORUM CANONIS CONSTRUCTIO (English translation by Ian Bruce) contains tables of logarithms, and explanations of the construction of the tables.
EDIT. Natural logarithms, and the formula $\ln x=\int_1^xdt/t$ defining them, were known long before Euler. Modern texts usually define them as the inverse function of $e^x$, but historically this was not the case: $e^x$ is much later invention than logarithms.
According to Wikipedia, this definition using "the area under the hyperbola" is due to
Alphonse Antonio de Sarasa (1649), that is a century before Euler.
Comment: Good answer, i upvoted it. But you should add a sentence that actually answers the OP's question. He asked specifically about the natural logarithm 'ln'...so what i gather from your question is basically, that logarithms in general were already known, and a numerical approximation of e was already known, but until Euler established e as a limit the 'real' natural logarithm wasn't invented? So e and ln were born simultaniously?
Comment: @Matthaeus: Napier's logarithms were not natural and were not logarithms, strictly speaking. But that his base was close to $e$ shows that he somehow understood what the "natural logarithms" and the "natural base" is.
Comment: Wikipedia is write. If you read back through old texts, it's called the *logarithmus hyperbolicus*
Comment: congratulations on gold ([announced](https://chat.stackexchange.com/transcript/message/55564203#55564203)) I wonder if this old question has a better answer. I can post something similar here in hsm if helpful (it's too old to migrate). [How did the definition of complex logarithm evolve since Cotes (1682-1716)?](https://math.stackexchange.com/q/2395338/284619)
Answer:
Which came first, the natural logarithm or the base of the natural logarithm?

Quick answer: logarithms came before Euler's Number, $e$.
The Euler's Number, $e$, one of the most important mathematical constants is an irrational number closely related to growth and rate of change. The earliest written observation of number approximate to $e$ was made by J. Bernoulli, around 17-th century, arising from experimenting with the length and number of intervals of compound interest over an initial investment, where he observed a pattern which was later identified by Euler (and Gauss) as we know it Today.
The logarithms were developed, a century earlier (early 1600s) by Napier, as a practical tool for Astronomical calculations related with the multiplication of large numbers.
Around that time (middle 1600s) the concept of function became relevant together with Calculus, which is essentially the language of rate of change. Main part of that "language" is played by $e$ which arises naturally in expressions and functions related to growth. Calculus provided the "platform" that allowed $e$ to be associated and connected with another mathematical (already existing) branches - geometry (areas under a curve (hyperbole)), trigonometry, etc. leading to a culmination, which is named: "The most beautiful formula." (Euler's identity.): $$e^{i \pi} + 1 = 0$$ applicable and helpful in numerous areas in science.
Answer: Logarithm tables have been used since at least the middle ages by merchants in order to perform big multiplications. Guess that makes them come first, although the formal definition came latter, as shown by Alexandre's answer.
Comment: It is not true that "logarithm tables" were used since the "middle age" by merchants. The first log table was published by John Napier in 1614, and it was primarily for the use by astronomers. not merchants.
Comment: "Middle ages" usually means up to the 15th century, which is not a time when merchants would "perform big calculations" with logarithms. A lot of the need for mathematical ease was for the demands of astronomy and navigation. In the late 1500s, [prosthaphaeresis](https://en.wikipedia.org/wiki/Prosthaphaeresis) provided a method but it was largely abandoned once logarithms came into use.