Wind instruments and sharp keys

Question: As far as I know, most of the wind instruments are transposing, and many of them are either in B, in E-flat or in F - these keys make them more suitable for playing in "flat" keys. My question is why there are no counterparts for playing in "sharp" keys (for example, sounding a semitone lower - in A, D and E, respectively), like clarinets, which do exist in 2 "kinds" - in B for using in flat keys and in A for the sharp ones?
Comment: The alto flute is in G, so add one flat. Yes, it's not common.
Answer: The clarinet is different from almost every other wind instrument because it overblows at the twelfth, not at the octave. Therefore, the notes to cover the "break" between the lowest octave and a fifth are technically more difficult, especially on early clarinets with a limited number of finger-keys.
The orchestral use of B flat and A clarinets dates from before the instrument was redesigned following the Boehm system in about 1840. (Note, the redesign of the clarinet was not actually done by Boehm himself). Apart from the extra lowest note, most "A clarinet" parts can be (and often are) played successfully on modern B flat clarinets.
For an full ensemble of wind and brass instruments, there is no need for two "sizes" a semitone apart - most music is written in flat keys, and arrangements are often transposed up or down a semitone.
Because of the acoustic compromises needed in designing brass instruments with valves, the "best sounding" keys have a few flats more than the natural key of the instrument. For example D flat is a popular key for brass ensembles, corresponding to written keys of 3 and 2 flats for the Bb and Eb instruments.
As a relevant bit of trivia, 19th-century military bands often used piccolos in D flat because of the use of flat keys - the small physical size of the piccolo means it has fewer keys than the bigger woodwinds. This was often not explicitly marked in the score or the player's parts - and was sometimes erroneously indicated as "Piccolo in D," not "D flat".
Comment: "brass instruments with valves, the "best sounding" keys have a few flats more than the natural key of the instrument": is that because C# comes earlier than Db in the series of sharps resp. flats, and that fingering 123 is too sharp on brass instruments? If no, what acoustic compromises do you mean?
Comment: It feels like you might have the knowledge to answer this question: http://music.stackexchange.com/q/39970/63
Comment: @Gauthier the answer that discusses intonation and fingering is the answer I would have given. If you look at a guitar fingerboard and measure the distance of the first 3 frets from the nut, it's obvious that the sum of distances to the first fret + second fret doesn't equal the distance to the third fret. But when you push down more than one valve on a brass instrument, you are combining several extra lengths of tubing in a way that is analogous to assuming the third fret *is* at the position of "first + second". Flat keys avoid the notes with the worst intonation problems.
Answer: To add to alephzero's notes on the clarinet,  I'm pretty sure Adolphe Sax designed his set of instruments so a musician could easily switch from clarinet to sax and back.  As it happens, there is a "C-melody sax" in rare use as well.
Now to the question of key signature: The resonances and timbres of keyed instruments depend on the bore and the bottom note (all keys/holes closed), not on the transposition.  For example, the Bb clarinet's low note is E, concert D.  This means one could write in a key which simplifies fingerings (which really doesn't bother anyone reasonably skilled) or in a key which produces certain sonorities.
It would take some work to provide a distribution of concert keys for which notable clarinet works exist, but I can say from experience that there's plenty both in a few flats and otherwise (including of course items in A or a for A-clarinet).
Answer: There are some instruments made for sharp keys.
A piccolo trumpet, D trumpet, A trumpet, D bass trumpet, D clarinet, A clarinet, G alto flute, G contra-alto flute.
These instruments are good with violin and guitar open strings.
Flat-keyed instruments need guitar capo or half-step up.

Wind instruments and sharp keys


Adobe e-book reader ("Digital Editions") not downloading on Mac OS X

Question: i recently bought a couple of books from ebooks.com, which i thought would be ordinary pdf files. After paying for them, and downloading them, you learn that while they are pdf files, they come with a lot of DRM baggage. The most conspicuous is that you can only view these files using an Adobe ebook reader called Adobe Digital Editions. (Note: this is not the ordinary Adobe Acrobat Reader, or anything close--it's a dedicated app for reading DRM-laden files.
Fine--i'll know better next time. Still, i paid for these books and there's only one way i can actually read them, which happens to be an App that i seem to be unable to download. Here's the error message i get:
"Couldn't write the application to the hard disk. Please verify the hard disk is available and try again"
I've tried on several different browsers. My rig is a MBP, OS X 10.6.2. I've also checked the Adobe boards and this doesn't appear to be a known issue, nor could i find anything on their discussion forums. And just to be sure, i've checked my hard disk--no problems, plenty of space, and i have no problem, nor have i ever downloading other apps.
Answer: Did you try with the package installer, not the flash installer ?


How to install tor meek TP on openwrt flashed router?

Question: I was trying to find out a way to install tor meek on OpenWRT. Can someone tell me how to cross compile the meek client with OpenWRT?
Answer: You can't cross-compile using OS, you need a cross-compiling environment and you're also required to cross-compile Go language from source. Also take a close look at special Go fork for OpenWRT
After that make a Meek source compiled =)
Answer: Meek is written in Go. It has pretty reasonable cross-platform compilation options (compared to some languages).
First, you don't only cross-compile based on the operating system, you cross-compile based on the architecture and operating system. You need to know what architecture your OpenWRT router is running on. Go supports quite a wide variety of options and since Golang 1.5 cross-compiling has been a lot easier.
https://golang.org/doc/install/source#environment

Choices for $GOOS are darwin (Mac OS X 10.7 and above and iOS), dragonfly, freebsd, linux, netbsd, openbsd, plan9, solaris and windows. Choices for $GOARCH are amd64 (64-bit x86, the most mature port), 386 (32-bit x86), arm (32-bit ARM), arm64 (64-bit ARM), ppc64le (PowerPC 64-bit, little-endian), ppc64 (PowerPC 64-bit, big-endian), mips64le (MIPS 64-bit, little-endian), and mips64 (MIPS 64-bit, big-endian).

Then, to build a copy of the meek-client, lets say for Linux on ARM64 you'd run a series of commands like:
export GOPATH=`mktemp -d`
export GOARCH=arm64
export GOOS=linux
go get -u git.torproject.org/pluggable-transports/meek.git/meek-client

and this should result in a copy of meek-client built for linux on arm64 in the $GOPATH/bin/linux_arm64/ folder:
$ file $GOPATH/bin/linux_arm64/meek-client
/tmp/tmp.kovJoNMmiL/bin/linux_arm64/meek-client: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), statically linked, not stripped

Then your OpenWRT's Tor then needs to be configured to use meek, assuming you installed the meek-client you built before at /usr/local/bin/meek-client and you wanted to use the google domain front you'd add some lines to your torrc like these
ClientTransportPlugin meek exec /usr/local/bin/meek-client --url=https://meek-reflect.appspot.com/ --front=https://www.google.com/
UseBridges 1
Bridge meek 0.0.2.0:1


How can I sell used RAM in EOS?

Question: I'm conducting an airdrop to every eos holders(ie. about 163,000). I've done a requirement estimation and it has been found that around 20 mb ram is needed. 464.28 EOS is required to buy that much of ram as per current(22/06/2018) market price. Can I sell this much ram after my usage?
Comment: Possible duplicate of [How does buying and selling RAM work on EOS?](https://eosio.stackexchange.com/questions/88/how-does-buying-and-selling-ram-work-on-eos)
Comment: I'd say very similar, answer seeked in other question is what will I get in return for my RAM, this question asks can it be sold in general.
Answer: Technically depends on whatever smart contract you'll use for the tokens however I'll assume you're using the eosio.token contract.
You can sell this RAM only if you're able to unstake it, you cannot unstake RAM if it is currently being used, it is used in the multi-index containers which each row costs a portion of RAM.
In the eosio.token contract, there is a row for each holder of each symbol, therefore if you're sending to 163,000 STEVE tokens, you're going to need to pay for their 163,000 rows in that table + the CPU and bandwidth costs on top of that.
Once your RAM is committed to each of these rows, they will remain committed until a user has claimed it by transferring the token which then makes them the RAM payer or if the balance has reached a balance of 0.00 in which case the row is destroyed and RAM returned to whoever's RAM was used.
Comment: I have an idea of proposing a feature in the `eosio.token` contract which allows **anyone** to create a 0.000 balance of an existing symbol if they don't already have a balance. In the event of an Airdrop, you'd get users to 'register' themselves against the contract, which then you can then give them tokens. This I'd say would be tedious for the user but achieves no commitment of your RAM, just CPU & bandwidth. Let me know if you'd like an update should I end up proposing.
Comment: oh, right, if somebody transfer all his token to others, then you will get your ram back
Comment: @KemmyGuo Yeah, if someone does a transfer which reaches a balance of 0, the RAM will then get released.

How can I sell used RAM in EOS?


What is the first work of literature to reference existentialism?

Question: Taking a class on existentialism and literature and I'm curious how far back the idea has been referenced in literature. What is the first work of literature to express the ideas of existentialism?
Comment: @ChristopheStrobbe I am aware. Just because the term didn't exist doesn't mean the ideas behind it don't.
Comment: Definitely Hamlet, maybe The Tale of Genji (written 1008 ad), possibly the Mahabharata (2nd  or 3rd century bc) - I'll have to do some research and come back to this. You could maybe even argue The Epic of Gilgamesh. Perhaps you could add the definition of existentialism you want to work from?
Comment: @heather The term existentialism did not exist before the 1940s, so I'm curious to know how *Hamlet*, written around 1600-1601, would be able to reference its ideas.
Answer: I would say that it is very hard to nail down the precise first work or thinker to reference Existentialist ideas. The Encyclopedia Britannica makes references to 16th and 17th century thinkers including Pascal and De Montaigne as precursors to Existentialism, making references to their application of the Socratic method.

The problem of what humans are in themselves can be discerned in the Socratic imperative "know thyself," as well as in the work of the 16th-century French essayist Michel de Montaigne and Blaise Pascal, a 17th-century French religious philosopher and mathematician. Montaigne had said: "If my mind could gain a foothold, I would not write essays, I would make decisions; but it is always in apprenticeship and on trial." And Pascal had insisted on the precarious position of humans situated between Being and Nothingness: "We burn with the desire to find solid ground and an ultimate sure foundation whereon to build a tower reaching to the Infinite. But our whole groundwork cracks, and the earth opens to abysses." 1

In general, both the Encyclopedia Britannica and Wikipedia agree that the most direct antecedents to Existentialism were Nietzsche and Kierkegaard

Søren Kierkegaard and Friedrich Nietzsche were two of the first philosophers considered fundamental to the existentialist movement, though neither used the term "existentialism" and it is unclear whether they would have supported the existentialism of the 20th century. They focused on subjective human experience rather than the objective truths of mathematics and science, which they believed were too detached or observational to truly get at the human experience. Like Pascal, they were interested in people's quiet struggle with the apparent meaninglessness of life and the use of diversion to escape from boredom.2

From a literary perspective, the first and most significant proponents of an Existentialist philosophy were Dostoevsky and Sartre.

The first important literary author also important to existentialism was the Russian Fyodor Dostoyevsky. Dostoyevsky's Notes from Underground portrays a man unable to fit into society and unhappy with the identities he creates for himself. Jean-Paul Sartre, in his book on existentialism Existentialism is a Humanism, quoted Dostoyevsky's The Brothers Karamazov as an example of existential crisis. Sartre attributes Ivan Karamazov's claim, "If God did not exist, everything would be permitted" to Dostoyevsky himself, though this quote does not appear in the novel. 3

According to the Encyclopedia Britannica, the father of Existentialism is Dane Søren Kierkegaard.

The theme of the irreducibility of existence to reason, common to many existentialists, was also defended by the German idealist F.W.J. von Schelling as he argued against G.W.F. Hegel in the last phase of his philosophy; Schelling's polemic, in turn, inspired the thinker usually cited as the father of existentialism, the religious Dane Søren Kierkegaard.


restoring the finish of an oxidized polished aluminum frame?

Question: In the context of restoring the finish of an oxidized once-polished aluminum finish, is there anything better (easier) than 0000 steel wool with Marvel Mystery Oil? I am restoring an old Cannondale aluminum frame. Over the years, the environment has taken its toll. After renewing the driveline, I would now like to improve its appearance.
Comment: Note that the best way to preserve "bare" aluminum is via anodizing, and if the frame was originally anodized then "polishing" it will remove the anodized surface and make the aluminum more subject to corrosion.
Comment: I'd leave this to a professional due to the risk of leaving particles behind (see http://sheldonbrown.com/paint-prep.html#removal for details)
Comment: Kirk, did you ever solve this problem. A friend of mine has the same issue.
Answer: I think that polishing paste like Mother's Magnesium and Aluminum should be your first choice. If the result is not good enough, at least you will be sure that you didn't do any damage to the surface like you can do with wrong sand paper or metal wool. I would use sanding of any kind only when some scraping of the surface is necessary, to remove nicks and dents for example.
Last time I used bathroom cleaner Comet first which made the whole surface evenly gray, light and clean, I guess oxidation free. It was very matte but very evenly. Then I used Mother's Mag and it became shiny, not luster but nice.
Answer: Yes and no, it depends on how much elbow grease you want to put into it. If you just want to get the oxidation off, then you can use a grinder with a wire brush and go to town. Alternatively, you can use sand paper and do it by hand, with a coarse grain for the major stuff.
After that, it's all about details. You can work with successively finer grain to achieve a smoother, more uniform finish. And if you are feeling particularly picky, this is when you pick up some 00, 000, and 0000 steel wool and go at it. From there, you'll want to seal the frame with something to prevent future oxidation.
Comment: Steel wool is a bad idea; you will leave tiny steel particles engrained in the surface of the Al. This will rust, causing unsightly discolouration. Aluminium wool would be a much better bet (or stainless steel wool at a push).
Comment: @headeronly good point, I didn't think of that. You could probably use steel wool if you follow up with something else to take a layer off and remove remaining bits (or a good acid bath, etc). Plus, if you seal it right after that, it shouldn't rust!
Comment: Aluminum forms an oxidation layer any time it comes in contact with the air.  It's actually good and is why aluminum doesn't rust.  If you sand that top layer down it will just form a new layer of oxidation when it comes in contact with the air..  I am not an expert and may be wrong but I'm pretty sure..
Answer: I found this article to be particularly informative. I'll be using this method for my own bare aluminum frame.
It requires purchasing a couple small items, but uses proven methods.
http://www.blackmtncycles.com/2014/02/care-for-your-bare-aluminum-frame.html
Comment: Welcome to Bicycles.sx.com. In our format try to collect information directly here on the site, therefore answers that mainly consist of a link are sometimes frowned upon. Maybe you can edit your answer to include the main points from your linked site.
Comment: To build upon what @BenediktBauer is saying, if your link dies, the answer is no longer helpful. We want answers that are going to stand the test of time.
Answer: In my efforts to restore a Vitus 979 frame, I found that a combination of coarse and then fine grain bronze wool will eliminate the oxidation and restore the finish of the aluminum. Follow up with Mothers Aluminum Polish.
If the anodized portions contain oxidation and pitting, the bronze wool will finish it out but obviously the look will be less than aesthetically pleasing.  In my case, I will be painting over the anodized areas which are the tubes in the triangle. I have polished the head tube, BB casing, drops, forks and stays which are all non-anodized. Once finished, with restored Campy components, I hope to have a nice looking machine


Difference between RAM and buffer

Question: I have searched but didn't get any exact difference between RAM and a buffer. If both are used for temporary storage, then why they are named differently while both having same property?
Answer: Buffer is a concept. It's a structure used to hold data to keep it "closer" while you're processing it. Like buffering a YouTube video. Many types of memories are used as buffers. RAM is certainly great for holding buffers, but for large data you can also buffer data on a hard drive, or an SSD.
Buffers are mainly used to hold data that is costly to read and write (costly in terms of time, or bandwidth, etc), so you'd rather only read a chunk of it once, work on it, then write it back when you're done. And RAM is a good place to do that, unless your data is huge. As you know, current RAM goes from the hundreds of MiB (smartphones) to dozens of GiB (high end PC).
RAM is the specific type of memory. Lots of software uses it to hold buffers, but also to hold its own code, etc.
Answer: A buffer is usually used only as temporary storage while something is being transmitted or read. For instance, you might be reading data from a slow-response external storage medium (e.g., a CD) and processing it continuously. In this setting, the first process reads chunks of data from the medium and writes it to the buffer on demand, while the latter reads from the buffer as if it were reading from storage directly. This avoids deadlocks in that the latter process does not need exclusive access to the medium.
In contrast, RAM is simply what is used as main memory for the processes in a general-purpose computer. There might be several buffers not only in RAM but also in other memory units. Saying that RAM is used for "temporary storage" can be rather misleading since "temporary" here actually means "until the process using it is inactive or extinct" (and not "until the data is not needed anymore").
In summary, a buffer is an abstracted concept (and only really exists at the software level); RAM is a concrete type of storage technology.
Answer: SSD drives are often used as buffers. You wouldn't call an SSD drive RAM, would you?
RAM is Random Access Memory.
A buffer is a data structure used to optimise the flow of data.
You make a category mistake. You compare things that cannot be compared. It's like asking why your nose isn't called Usain Bolt when they are both running.

Difference between RAM and buffer


Do I need an Amazon account to use a Kindle?

Question: I am looking to buy a Kindle Paperwhite (7th gen).  Do I need an Amazon account for it to work? I just want to put books on it from my PC.  I cannot create an Amazon Account because I have no credit card, so will my Kindle register without it?
Comment: Possible duplicate of [Can you use a Kindle without an Amazon account?](https://ebooks.stackexchange.com/questions/6149/can-you-use-a-kindle-without-an-amazon-account)
Answer: You don't need a credit Card to register your amazon account.
With amazon account, it is much easier to send your personal books to your kindle:

send books an an attachment to your personal amazon email
Use browser extensions to send webpage directly to your kindle

Alternatively you can send books via USB cable to your kindle without using an account.
Comment: Yes but when I for the first time start the Kindle and have to Input an account, can I put in an account that DOES NOT have a credit card associated with it?
Comment: Yes. and I believe the first time you turn the kindle on, it already knew the account associated with amazon (according to person who buy the device). In my opinion, start a chat session with amazon support and ask them any question you have using [this link.](https://www.amazon.com/gp/help/contact-us/general-questions.html?skip=true)
Comment: No but I am not ordering it myself so it will not be my account.

I need to confirm this before I buy.
Comment: then ask amazon support as I said
Comment: @hacker804 It's possible that the person who buys the device can choose to NOT register the kindle to any account so that you have the option of assigning it to any account yourself.
Answer: I am not familiar with the paperwhite kindles... but with the kindle fires (at least that 2 latest ones) they read MOSTLY all epub and mobi files- but some just don't show up on the kindle. I have no idea why unfortunately, but if you have an e-book in the format of the actualy file- either epub or mobi- it will seem to recognize and store the book 80% of the time about. The method I use is the simple drag and drop from PC to correct folder on the kindle. Sometimes the books will show up in your library with a cover photo, and sometimes they will show up in your documents with the title and no cover, but still has the whole bookmarking/flip the page/ basic e-read features.
Answer: When you buy a Kindle you will get an account. When you turn it on, it will prompt you to create an ID and Password and will assign you a unique Kindle e-mail, regardless of who bought it. You'll use the e-mail to load things onto the Kindle. Kindles will read PDF's as well as Kindle documents, look to see what formats are covered when you get your paperwhite. Non-Books are mostly held in a Documents folder. Amazon accepts PayPal and debit card purchases, so I assume that's what you're using. And in any case, if a Kindle has reverted to factory settings (i.e. buying a used Kindle), it will always make the user register it anyway.
A word of caution, though, take a look at what format the books on your computer are in. Amazon won't convert EPUBs to Kindle format. If you buy a Fire, you can use the Bluefire app to read EPUBS that you load manually. I don't think that will work on a paperwhite--I know it didn't on my Kindle Touch.
Answer: DISCLAIMER: This is by no means a marketing stunt, at the end of the day you know what is best but from your description it was clear to me that you  might not be making the right decision. Just my 2p.
The benefit of using a kindle is the entire eco-system and infrastructure built around it by Amazon. If you take that away, the kindle is actually a pretty poor choice for an ebook reader. If you do not want to register your credit card and will not primarily buy your books from Amazon, you are subscribing to a world of hurt in my opinion. Please note that there are ad supported versions of the paperwhite and you need to pay extra to remove these. This brings me to the next leg of my answer.
My scenario was a lot like yours and I spent a lot of time researching the ereaders out there. I am confident to offer you the same advice and that is to actually go for a Kobo reader instead. That ereader is and a amazingly open device and very friendly towards people who would want to dump their own ebooks on to the device. Not only that, the book formats supports is great allowing you to read anything from comics (cbzs) to the industry standard epub files. In the future should you decide to buy books you can do so easily from the device itself using the kobo store.


Reverse engineering modern Intel CPUs

Question: Are there open source projects that completely restore the inner circuitry of modern Intel CPUs? Is it simply possible, or are circuits closed and/or protected by proprietary technology?
Answer:
Are there open source projects that completely restore the inner circuitry of modern Intel CPUs?

Not for modern CPUs. Not even for 10-15 years old CPUs.
In 2015 the reverse engineering of Intel 8080 was finished, and this CPU is from 1974 year (actually, Soviet i8080 clone KR580VM80A from 1980s was reversed). Both CPUs were made with 6 μm feature size, so the chip can be photographed using cheap optical microscope.
The report in english is here:
http://zeptobars.ru/en/read/KR580VM80A-intel-i8080-verilog-reverse-engineering
The project was coordinated here (russian): http://zx-pk.ru/printthread.php?t=23349&pp=40
Availability of detailed documentation (with block-schemes), low amount of transistors (4758 units), coarse features, single metal layer and readable dopant zones allowed to do this project.
Other successful project was MOS 6502 from 1975, 5-16 μm feature size, 3.5 thousands transistors - http://www.visual6502.org/ (They have big collection of chip photos, but they are not reversed to the schematics)
One of  KR580VM80A reversers reported project about reversing (russian) MIPS R3051 based Playstation 1  CPU made with 0.8 μm (800 nm) feature size in 1995. Project site is http://psxdev.ru/. This CPU has 250 thousands transistors and three layers of metal. In two years after start, good optical photos of chip and all its layers were made (all metals, silicon and dopant), many standard cells were identified, but only multiplier block was rather fully reversed.
So, 0.25 million-transistor device is out of reach for amateurs, and modern Intel devices have transistor count of 50 millions in Pentium 3/4 (2000, around 130nm), 50 mln in Atom (2008, 45nm); 200-400 mln in Core 2 (2007, 65-45 nm) and more then 1000 millions in bigger chips like Core i7 (2010, 32nm).

Is it simply possible, or are circuits closed and/or protected by proprietary technology?

The circuits and its "sources" (verilog) are proprietary; the software used to convert them into the transistor pattern is proprietary (some by Intel, possibly some by other vendors). And there are not any chance to readout the schematics back from the die (the fabricated chip), because features are too small to be visible in optical microscope; and dopant levels are too low to be read out by even scanning electron microscope (SEM) for the full chip. There just too much information inside the chip (I consider modern photo lithography tools to be most advanced data transfer tools made by mankind; with terabytes per second transferred from photomask into the wafer).
For example, the paper Stealthy Dopant-Level Hardware Trojans says:

Also, optical reverse-engineering does not usually allow to detect
  changes made to the dopant, especially in small technologies. A
  dedicated setup could eventually allow to identify the dopant
  polarity. However, doing so in a large design comprising millions of
  transistors implemented with small technologies seems impractical ...

There are several companies which are able to reverse engineer some parts of modern chips, but Intel's CPUs are too big to be fully reversed (this process will have impractical cost both in money and in man- and computer-hours). For example, reversing leader, Chipworks - www.chipworks.com - lists some examples:

Examples of our experience and capabilities

Stand-alone and embedded memory
Field programmable gate array (FPGA) and other gate arrays
Analog-to-digital converters (ADC) and digital-to-analog converters
(DAC) PLLs and clock generators
Wired and wireless devices, including transceivers and mixers
Advanced CMOS microprocessors, graphic chips, DSPs, and microcontrollers
RFIDs and smartcard chips
Power semiconductor devices including regulators and high/low power designs

But most of their projects were reversing of some small chips (made with not the most advanced technology) or reversing of some parts of chips.
They are able of opening chip, making some nice SEM photos of chip cross-section, or optical photos of full die top metals or silicon layer in very coarse resolution (good to measure area of chip or its blocks, but no reversing from this).
They sells some photos and reports about Intel chips, for example of Core i5-660:
* 200 USD for die photo (top metal?)
* 2500 USD for M1 (lower metal) photo
* 11000 USD for report of used package
* 15-15.5 thousands USD for  Layout and Design (DfM) Analysis or Transistor Characterization
* 24.5 thousands USD for Structural Analysis Report
Some people think, that it will be much cheaper to redevelop the modern CPU than trying to reverse engineer it from the chip. And, possibly, some federal agencies may infiltrate their federal agents into the company to try to steal the CPU sources; but I think that they can get sources to the agent's hands, but will be not able to get them outside the buildings.
Comment: There are good methods for huge companies. As I know, Google prohibit any data storage device to leave datacenter - they even destroy  broken hdd inside the building https://www.google.com/about/datacenters/inside/data-security/ "We destroy hard drives.." They have a lot of internal rules, even for suppliers (Intel): https://supplier.intel.com/static/governance/documents/SSRE%20-%20Ver%205%200.pdf - 4.a "background checks to the extent permitted by applicable law.", 4.c, 5. No open Internet access (7. f,g,h,i,j). Even secure chain http://web.mit.edu/supplychain/repository/intel_lund_120502.ppt
Comment: Intel threat model - https://www.sbs.ox.ac.uk/cybersecurity-capacity/system/files/Intel%20-%20Threat%20Agent%20Library%20Helps%20Identify%20Information%20Security%20Risks.pdf Threat Agent Library...2007 wp by Casey - includes "external and internal threat agents ranging from industrial spies to untrained employees" .. " ranging from _government spies_ to untrained employees".. "Table 2. (Strength of Threat rating is proprietary and not included) .. Government Spy; Insider; Tactics: Theft of IP or business data; Description: State-sponsored spy as a trusted insider, supporting idealistic goals"
Comment: In newer wp - 2010 (link from https://communities.intel.com/thread/49315 by Casey) - https://communities.intel.com/docs/DOC-4693 Whitepaper: Prioritizing Information Security Risks with Threat Agent Risk Assessment - they still think about spies, but Highest Risk is assigned in the example to "Disgruntled Employee" (Will they have their own Snowden and why NSA's risk assessment failed for this disgruntled backup administrator? - http://arstechnica.com/information-technology/2013/08/sysadmin-security-fail-nsa-finds-snowden-hijacked-officials-logins/ - the " two-person" rule is only after Ed.)
Comment: Intro paper from Chipworks about reverse engineering of chips http://www.chipworks.com/images/content-documents/TCA/whitepapers-articles/Chipworks_Intro-ICRE.pdf - page 8: "Circuit extraction of semiconductor chips becomes increasingly more difficult with each new generation. In the "good old days" of 10 to 20 years ago, a circuit  analyst's life was much simpler. A typical IC of those days may have had one layer of metal, and used 1 µm - 2 µm technology. After package  removal, all features could usually be seen from the top level metal planar view".. Optical for 250nm; SEM for 180nm and less
Comment: This looks like a 4004 (1971) reverse engineer from 2009: http://www.4004.com/ the grandfather of modern CPUs.
Comment: Do you have any sources about the federal agents or Intel's security methods? Intriguing stuff.
Answer: OpenCores is a project aiming at rebuilding the design of usual integrated-circuits with Open Source licenses.
One of the sub-project is dedicated to rebuild the i386 architecture, it is called Zet.
I don't know how they rebuild the instruction set, there must be a bit of reverse-engineering. But, the specifications given by Intel should be enough (of course, this design will be far from being as efficient as Intel CPUs. Intel did a lot of progress during all these years, it would be difficult to get the same result at the end).
But, I don't know if this question is really related to reverse-engineering (yet, I don't know where you should have asked it, so...).
Answer: I found this site containing a hires zoomable picture of the 80486.
And here an effort to reverseengineer the AMD microcode format.
Googling for siliconpr0n and intel  yields even more people trying something similar.
Answer: From a now deleted Quora comment:

Smart Imaging Technologies (archive) can reverse to the gate level and output VHDL, but I don't know at which cost
3D x-ray tomography is a new technique in vogue, and might dispense scraping layers off the chip. Googling it leads to a few papers:

http://iacr.org/archive/ches2009/57470361/57470361.pdf |
http://dforte.ece.ufl.edu/Domenic_files/ISTFA_2015_PCB%20RE-final.pdf

https://www.youtube.com/watch?v=WOZqoTuAGKY "Catching a single Transistor - We're looking inside the i9-9900K: Prep and expensive equipment 1/3" is a 2019 series of videos showing concretely how it could be done, worth watching to feel the difficulty of the process first hand

Non-Intel superset: https://electronics.stackexchange.com/questions/13472/is-it-possible-to-reverse-engineer-a-chip-design
Answer: ReProgramming the processor is quite difficult (you will nead to create your own simi motherboard) . But reconstruct the microprocessor (changing its architecture and developing your own firmware by  micro ops )is impossible in modern inter microprocessors  . Even the updates to firmware is encrypted with key that is kept inside the processor.
This beacause intel wants to protect its processors firmware from malware. And if the firmware is infected the result will be a real disaster.

Reverse engineering modern Intel CPUs


VBScript gets opened in text editor instead of being executed

Question: I'm part of a Windows Server 2008 domain. There's a login script (supposedly configured to execute on login via GPO) that sets permissions for network shares. However, instead of being executed, it's opening in my text editor. I presume that there's been a registry change that affects the default shell ("double click") action for .vbs, and that Windows Server 2008, or possibly this particular GPO, assumes that the default shell action is "execute". Is there a way to fix this locally? Is there a way to fix the GPO to explicitly pass the script to the Windows script host instead?
Answer: It appears Windows server 2008 still defaults to wscript $1 as the default action for the vbsfile type, so perhaps this was a local change that can be reversed.
Can you change the GPO policy for the login script to run a command line instead of the script directly?  Something like:
<code>wscript ourlogin.vbs
</code>
Answer: I've never seen this particular issue, but you can sort out file associations with Group Policy Preferences. Either:

Computer Config -> Preferences -> Control Panel Settings ->
  Folder Options
(Right Click -> New File Type)

or

User Config -> Preferences -> Control Panel Settings -> Folder Options
(Right Click -> New Open With)

Computer config gives you full configuration options similar to manually changing it in Folder Options on the machine. User config just gives you an "Execute" option which you can set as default.
Computer config would be the preferred - just go onto a working machine and duplicate the settings. I think this would work for you, but you'll need to experiment:

Alternatively, as @uSlackr, run it as a batch script and call the VBS. Though that's more a workaround rather than a fix in my opinion.
Answer: Sounds like your clients need their default action for VB Script files to be changed from open with Notepad.exe to open with Cscript.exe or Wscript.exe.
The following url provides registry files to reset this.  The XP reg file matches my XP registry.  You'll need to check on the Vista and W7 files.
http://www.nilpo.com/2009/07/windows-xp/restoring-vbs-vbscript-script-file-file-associations/
You might want to check out why someone changed this setting on the clients - This is a secure setting, and changing it may violate a policy, or may be set back by whatever set it this way in the first place (GPO,  AV client, etc).


Can toothbrush bristles be printed?

Question: Is it possible to print toothbrush bristles using a common FDM 3D printer? I am particularly interested in the width of bristles, closeness together of each bristle, and the flexibility of each particular bristle.
Comment: Hello @J. Roibal, I noticed your question has been up for a while now. Have any of the answers below been able to solve your question? If so, would you mind accepting the appropriate answer. If not, what is missing so that we may help you further? Also, if you have figured it out on your own, you can always answer and accept your own solution. Thank you.
Answer: Actually last year a group did use a normal FDM printer to 3d print hair, brushed, etc. See the press release from Carnegie Mellon University
https://www.engadget.com/2015/10/29/3d-printing-hair-is-as-easy-as-using-a-hot-glue-gun/
http://technabob.com/blog/wp-content/uploads/2015/11/3d_printed_hair_by_Gierad_Laput_Xiang_Chen_Chris_Harrison_1.jpg
That said as far as I know you will not have access to this process, and is probably under a mountain of patents and other innovation killers.
Now how to do this outside of fancy software.
For a FDM printer the smallest nozzle I ever got was 0.1mm, it jammed instantly. One could print rows at this precision.
Now we have to move to something more advanced, such as DLP. Not the materials you want, but closer to the size you want. a formlabs can print at 25 microns. Which as a hair is 17 microns, you are "close enough" .. but a resin would be brittle and break. They do have other materials such as flexibles, but I am not familiar with them enough.
Also just going to mention. Tiny slivers of plastic is more likely to cut you than comb you.
Comment: One additional note on the formLabs  (form1+) it can create features that are 25 microns but in my experience getting it to reliably print that is hit or miss, especially when they're printed extremely close together like on a bristle.
Answer: At this point, an FDM printer probably wouldn't produce good results if you intend on printing the same design as current toothbrushes.
Each strand is about 0.007" in diameter which is slightly larger than the typical minimum diameter that can possibly be extruded. This doesn't leave much room to provide a well enough surface between layers.
With features this small you might run into issues with resolution and accuracy of the machine. The resolution may determine how well the strands are printed separately. The accuracy may determine how well each layer print over each other. If your machines accuracy is about 0.0005", then expect your layers to have run-out of about 0.0005"-0.001" on a 0.007" size feature. I'm also not accounting for how well the machine is maintained/tuned, which could detriment both resolution and accuracy.
So, it's possible on an FDM, but not probable at this time.
To help your odds:

Slow your feed rate way down (maybe 30-40mm/s)
Watch over and under extrusion. It will be more evident on smaller features like this. It either will look like a big blob or pretty much nothing. You should have settings in your slicer to help compensate.
Clean your extruder and drive gear and tune the tension on filament in the extruder assembly.
Use quality filament! If the filament is out of round, then over/under extrusion will occur.
Be mindful of any health organization requirements on the type of materials you're allowed to use for something that goes in your mouth. The same logic goes for ensuring you don't print the bristles in something that can mold. I believe nylon is safe, at least in the US, but don't quote me on this.
Comment: We had a long conversation about it in the facebook group I run, 3d printing hobbyists. The issue comes down to your machine is not going to meet food grade / clean room standards. The member who worked in that space was very sure about it. The plastic will.
Comment: That's right! There's the issue with contamination in the nozzle and build plate setups (tape, glue, etc.), right?
Comment: Just to add to this, even FDA approved printed materials would not qualify for in the mouth. As ones printer will not meet FDA standards.
Comment: @StarWind do you happen to know how the printed part would not meet FDA standards? Not even for natural PLA or Nylon?
Comment: I thought it was silly, given the temps we are talking about
Comment: Theres a lot of points of failures for contamination. This discussion was primarily about the machine it self. Oil, blood from cuts, unwashed hands from employees. Then the enviorment it is in. A Chipolte grill is cleaned and  taken care of. Employees have hairnets and so on. A dirty workshop is another vector.
Answer: I have had a go at doing something for a christmass tree using a drop loop technique. You could use the same method or somthing similar to try and create something that looks like toothbrush bristles, but I don't think you would want to try cleaning your teeth with it.
Comment: Could you maybe add a bit more detail? What's a "droop loop" technique?
Comment: Basically, the printer prints a line out from the model in thin air and then back to the model creating a loop or string of filament.

Can toothbrush bristles be printed?


Importance of recursion in computability theory

Question: It is said that computability theory is also called recursion theory. Why is it called like that? Why recursion has this much importance?
Answer: In the 1920's and 1930's people were trying to figure out what it means to "effectively compute a function" (remember, there were no general purpose computing machines around, and computing was something done by people).
Several definitions of "computable" were proposed, of which three are best known:

The $\lambda$-calculus
Recursive functions
Turing machines

These turned out to define the same class of number-theoretic functions. Because recursive functions are older than Turing machines, and the even older $\lambda$-calculus was not immediately accepted as an adequate notion of computability, the adjective "recursive" was used widely (recursive functions, recursive sets, recursively enumerable sets, etc.)
Later on, there was an effort, popularized by Robert Soare, to change "recursive" to "computable". Thus we nowadays speak of computable functions and computably enumerable sets. But many older textbooks, and many people, still prefer the "recursive" terminology.
So much for the history. We can also ask whether recursion is important for computation from a purely mathematical point of view. The answer is a very definite "yes!". Recursion lies at the basis of general-purpose programming languages (even while loops are just a form of recursion because while p do c is the same as if p then (c; while p do c)), and many fundamental data stuctures, such as lists and trees, are recursive. Recursion is simply unavoidable in computer science, and in computability theory specifically.
Answer: Computability theory is the study of computable functions :-).
Such functions are usually (in this community) defined as functions that can be expressed with a Turing machine.
More formally a function $f: \mathbb{N} \mapsto \mathbb{N}$ is computable if there exist a Turing $T$ such that if the input to $T$ is $x = 1^n$ the output of $T$ is $1^{f(x)}.$
As it turns out if you define computable functions in this way (programs) they are equivalent to the set of functions one can obtain by using the rules  described here. They are called recursive functions since one of the rules for obtaining such functions is a recursive definition (See the 5th rule on wikipedia).
So the reason why recursion theory has much importance is equivalent to the question of why are computable functions important. And the answer to the latter should be quite obvious :)


How do I refer to someone's family member who's relative age I am unsure of?

Question: Is there any way to refer to someones family member, lets say brother, who's relative age I am unaware of and consequently am unable to decisively call 弟弟 or 哥哥?
Is there some sort of rule, like assume they are older?
Comment: Can you provide a typical scenario ?
Answer: You could use the terms 兄弟 and 姐妹.
For example, lets say you know 小明 and 小華 are brothers but don't know who is older.  You could then say

小明跟小華是兄弟
Answer: There's no rule in a such situation. You can always ask politely or figure out the relationship from conversations.
But there's no harm in assuming they're younger than you or the person introducing you and that family member, especially that relative is a female ;)
Answer: let me use "him" to instead of the "someone", "other one" instead of "his family member", than suppose that other one is male. ccording to what you say.you must have a good relationship with him
if he haven't introduced other one yet, you could ask him

"他是你弟弟/哥哥? 他叫什么名字? 我比他大吗?"

so than, you could decisively call other one "弟弟/哥哥"
unless other one is older than you, you can call "哥哥" consequently. otherwise
if other one is younger than you. i think call the first name is better, or the nick name which "he" call other one. just follow him.


How can I check my balance in mining pools that dont have an login/account option? like XMRpool

Question: On XMRpool_eu there is no account or login, so how can I check my balance? I assume that's why there is the "Your Stats & Payment History", on the home page, but it doesn't work for me. It says "Enter Your XMR address or address@paymentID", so I though it's ok, when I put in my wallet adress, but it says just "not found". Can you help me? I started to mine yesterday, maybe I have to wait? Til when? I understand I can not see any payments yet but the worker should be find, because I am sending results to the pool. So at least I should see my stats. Thank you
Answer: So problem solved - I did a stupid mistake. I did everything acording to this tutorial https://www.usxmrpool.com/#easy_mining_guide, which I find well done (for noobs like me), but I wanted to mine in a different pool, than the tutorial shows. When I checked the pool adress in config file, I overloocked that I didnt change it. There is a lot of pools with similar names so be avare of it (like xmrpool.eu and usxmrpool.com).
Thank you
Answer: You will see your starts with the pool by using the same address as in your miner configuration.
Note that it may take some time before first stats appear, and you will see a pending balance only after the pool finds a block in which you took part. Also, to actually receive a payment to your wallet, your pending balance must go over the pool's payout threshold, so it may take some time - depending on your hashrate and pool payout policy.
If you still don't see anything, make sure that your miner is correctly configured ie that you actually changed the mining address in the config, and that it's communicating with the pool and submitting valid shares.


How can i measure the power consumption of a PoE switch?

Question: I have to measure the power consumption behavior of switches which are powered with PoE and which also provide energy to other devices. How can this be done?
regards
Comment: which model / manufacturer?
Comment: Plug it into a meter?  http://www.degreedays.net/kill-a-watt-meter
Answer: If I am reading your question right, you have an edge switch that is both POE-PD (powered device) and is also a POE-PSE (power sourcing equipment).  I assume this switch is hooked up to a larger distribution switch which is capable of generating enough power per port to supply the combination of the edge switch and some combination of endpoints like IP phones or cameras.
If your distribution switch is a Cisco, then show power inline {port} will show POE power used by that port.  So first plug in the switch by itself and measure power draw at the distribution switch port.  Then plug in each device and measure the incremental power draw.
Also if you are feeling motivated, you could plug your endpoints into the distribution switch directly and measure their power draw individually.  This would give you some insight into any additional power loss due to the cascaded POE setup.
Answer: If the switch is managed it is a very good possibility to have snmp enabled. If that's the case you will have to setup a client that pulls at regular intervals the values from the snmp OID in respect to power consumption.
Answer: you cannot if the POE switch does not have it's own management interface. there are many passive POE switch and device which consumes power only and did not negotiate. but if you have an managed  power source, at least you could get the port output power from its management interface.
for a general rule of thumb, check the power source switch per port power output, and make sure the wattage of the chaining device are satisfied. You shall found cascading seems impossible since typical 10W per port cannot support lots of devices. probably 4-5 is maximum.
by the way, for many passive device, it also draw power from computer LAN port, so make a dummy connection to a desktop computer is a good idea if you have encounter not-enough power situation. just make sure your computer support wake on LAN (idea: no need to enable, just make sure the LAN card still on while computer turn off)


Does SO store any data for unregistered users in the database?

Question: Or is everything saved in a cookie? I am aware that unregistered users are tracked by their cookies, but I think SO needs some reference to the owner of the question, and thus they must store some data?
Comment: They save quite a bit, including ip and such.
Comment: @drachmenstern, what is the point of storing the IP? How does it help? I mean it's not a reliable way of ascertaining identity.
Answer: Yes, of course.. Also because when they register they have all their old posts assigned to their account, so at the very least they have to save enough data to do that.
Answer: Unregistered users are essentially the same as registered users; the only big difference is their OpenID is a randomly generated GUID:

If they do decide to "register" the GUID is replaced with their actual OpenID, which will let them login in the future


Could a graphic card function with full capacity eventhough its fan has stopped working?

Question: I have a Palit ATI Radeon HD2600 Pro and the fan has stopped working. Does this mean my graphic card is useless/not at full capacity? what could have caused it?
Answer: Relatively old graphics card usually do not implement thermal throttling very well. If the fan stopped working then in case the processor is stressed, then the power use will go up, and fried chip is a definite possibility.
The caveat here is how big your heatsink is. if what you have is something like this: (link: http://www.palit.biz/main/vgapro.php?id=104 ) then I don't think it's going to work very well. You better get another card ready.
I have personally seen HD2600 pro cards with passive cooling though. but those are big, big heat sinks with heatpipes.
Answer: The fan is to help cool your card's chips.  Without the fan, the chips will get hotter than they should which will lead to errors/damage.  You can get a replacement fan and everything will be fine (unless there is already heat damage).  Take your card down to a local computer repair place and they will probably be able to provide you with one.
The fan probably just wore out.  If the insides of a computer are not cleaned pretty regularly (once every 3-6 months) you can get quite a dust buildup.  Dust bunnies and fans don't play well together.


What does kansui do to dough in noodle making?

Question: I'm trying to understand how to properly prepare hand pulled noodles. I've read about Kansui and Lye water and in some instances I've read that they serve a similar purpose. However, after some reading, it seems that kansui could potentially affect the dough differently than lye water. Some expert insight into this would be appreciated very much.
Comment: See http://cooking.stackexchange.com/questions/9072/what-flour-and-technique-do-i-need-for-hand-pulled-noodles
Comment: What is kansui?
Comment: The link TFDs comment explains kansui. Thank you for the link TFD I'll review
Answer: Kansui is a mixture of sodium carbonate and potassium carbonate, both alkaline. Since lye is also alkaline, it could serve a similar function in the dough but it would depend on the relative strengths of their alkalinity.
Specifically, alkaline water interfere with enzymes in the flour and thus inhibit the development of gluten, allowing for the dough to be stretched more readily. That being said, you need some gluten development or else the dough won't form.
Alkaline water also will change the color yellow and make the noodles slippery on your tongue. This reaction is the same one that would take when you combine soap with water.
Harold McGee wrote an article in The New York Times about the effects of alkalines.
All this being said, I've only made ramen style noodles, not the hand pulled ones. Your best bet would be to try both and see whether there truly is a difference or not... but I imagine the most traditional method would be to use kansui or jian.
Answer: In accordance to this page the lye water only has a minor effect on the ability to pull the noodles:
http://www.lukerymarz.com/noodles/ingredients.html

Lye water is supposed to be the secret ingredient in hand pulled
  noodles. I've tried recipes with it and without it, and it does not
  make the dough any easier to pull. In fact, if you use too much of it,
  you'll make the dough IMPOSSIBLE to pull. Something about the basic
  nature of it causes the gluten to tighen up.
  Adding lye water or baking soda at about 1% (more will ruin the dough) will adjust the texture of the noodles a bit. The flavor is supposed to be slightly different, too, but I haven't noticed a difference.

Your question is from 2012. What did you learn from your experiments? :)


What's the best way to move a list from one site to another?

Question: I know you can backup site collections with stsadm -o backup, and you can backup sites with stsadm -o export. But what's the best way to copy a list? I've tried to use the save as a list template and include content, but not all the columns came across.
For example I had a lookup to another column in the same list but the data was totally messed up. only about 10% of the values were correct. I heard this is supposed to be available in 2010, but what's the best way to copy a list in 2007.
Answer: I used the stsadm extensions to be able to import and export lists and libraries.
Comment: Can you give me more info? I'm in the Air Force at work and the link you posted is blocked, as a lot of blogs and sites categorized as none are.
Comment: It's a set of extensions for stsadm which allows you to export and import lists and libraries using the migration apis.
Answer: You have already tried the best way, Save as Template and add it to the New Site. And to make the Look Up field work refer to this article that provides an alternate to do it.
Also one another way if wanted to do is to Create a List Template and Deploy it as a Feature using WSP solution, but if you are going to use this List only Once then you don't need to create a List Template. One Another item to note in the List Template is you will have to Hand code the XML with the Data contained in the list. Here  is a nice article on how to create a List Template.
Comment: I'll give that a shot. Will this also work with large lists or libraries ? I've heard that's another limitation.
Answer: goign to Site Settings -> Site Content and Structure, I created a new list in the new site with it's default list structure. Then I went to the old list and selected all the data rows then copied them to the new list. SharePoint copied the data and the list structure to the new list and made the new list look and work just like the old list. I was very happy.
Answer: Using the content deployment wizard (http://spdeploymentwizard.codeplex.com/ ), you can export a specific List or document library and then import it to another site.
This is a graphical wizard that displays all site content in a tree like view then you can select what lists or libraries to export. You can then use it again to import whatever you exported to the new site.
Answer: I am not sure what is the best way, but I did it using a Console App, with following code,
        SPList myDestinationList = web1.Lists[destinationlistName];
        SPList mySourceList = web2.Lists[Form1.OldListName];
        SPQuery mySourceListQuery = new SPQuery();

        mySourceListQuery.Query =

            "<OrderBy><FieldRef Name='a' />" +
                     "<FieldRef Name='b' />" +
            "</OrderBy>";

        SPListItemCollection mySourceItemColl = mySourceList.GetItems(mySourceListQuery);
        foreach (SPListItem mySourceListItem in mySourceItemColl)
        {
            SPListItem myDestinationListItem = myDestinationList.Items.Add();

            if (mySourceListItem["a"] != null)
                myDestinationListItem["a"] = mySourceListItem["Title"];

            if (mySourceListItem["b"] != null)
                myDestinationListItem["b"] = mySourceListItem["Location"];

            web1.AllowUnsafeUpdates = true;
            web2.AllowUnsafeUpdates = true;
            myDestinationListItem.Update();
            web1.AllowUnsafeUpdates = false;
            web1.AllowUnsafeUpdates = false;
        }

It did worked with Custom columns and lookup columns as well.


How does gradual hop infusion affect flavor and aroma?

Question: I only make IPA's and have read about some IPA makers introducing hops gradually over the boil vs. adding the the "aroma" dose during the last 5 or 10 minutes of the boil. I understand that hops added early in the boil are used for bittering and the late introduction hops add flavor and aroma. Does this hold true for the gradual addition of hops or does this process affect the outcome in a different manner?
Answer: The general ideas of hop bitterness, flavor and aroma related to time in the boil to hold true.  Continual hopping doesn't generally produce any different aromas or flavors in my experience.  In fact when over done the beer can taste fairly grassy.
I don't know of too many brewers that do this still.  Its labor intensive and has a fairly low return for effort, compared with more interval hopping schedules.
I'd say that modern IPA methods seem to have evolved into a focused bittering charge at the start of the boil.  Brewers tend to be focusing on bigger and bigger additions late in the process or even post boil.  I am specifically talking about 10min additions, flame out or whirlpool additions (hop standing).  Furthermore, brewers seem to be getting more innovative with the duration and temperatures of their dry hop additions.  Including pulling hops out and adding new rounds of hops as a second dry hop regime.


Kitchen sink backing up problem

Question: I have side by side sinks in the kitchen. When one sink drains, it backs up into the other sink.  I have removed the trap and it is clean, however, the problem still exists. What am I overlooking? How can I correct this problem?
Answer: There's a blockage farther down the line somewhere. It is most likely right where the trap arm connects to the vent and vertical drain. Try to auger this fitting out. Access by removing the trap and hopefully the adapter that turns down into the trap. If the adapter does not come off, you'll have to work through it's bend.
If you can't get a clean running drain by working at this fitting, it is time for professional assistance.

Kitchen sink backing up problem


What does it mean when an online store says "Nikon USA model"?

Question: What does Nikon USA model mean? At some online stores they specify USA and they are a bit more then the ones at the same store that do not say USA.
Comment: See also [Can I buy gray market camera equipment from reputable web sites in the US?](http://photo.stackexchange.com/questions/4616/can-i-buy-gray-market-camera-equipment-from-reputable-web-sites-in-the-us)
Answer: Products specified as USA are intended by the manufacturers to be sold only in the U.S. and the warranties are generally only applicable if the item is bought in the U.S. or shipped to the buyer in the U.S. from a foreign seller. The other items are usually the identical product but are not intended by their manufacturers for sale in the U.S. These are sometimes referred to as Grey Market items. If you purchase such a product and have it shipped to an address in the United States the manufacturer might not honor the warranty if you need service or replacement during the warranty period.
In general, online stores that sell grey market items are viewed as being a little shady and are sometimes known to use deceptive business practices to increase their profits on a sale. There are exceptions, especially stores such as B and H and Adorama, who offer gray market items to their international customers as well as their customers in the United States.
For more on how a shady grey market seller operates, see this answer to another question.
Comment: +1, but note that B&H offers grey market products to _all_ customers, including US customers who choose to forgo the US warranty. See [B&H's page about grey market products](http://www.bhphotovideo.com/find/HelpCenter/USGrey.jsp) for more.
Comment: B&H also is pretty good about notifying when items are Grey Market and what that may mean. Shadier vendors are likely to downplay that information.
Answer: The less expensive, non-USA versions are likely gray market cameras, often exactly the same device in about the same packaging, but imported by someone other than a Nikon-authorized importer and therefore lacking a warrantee.
Comment: Since Nancy is seeing both USA and grey market items at the same site, it would follow that they are either an authorized Nikon dealer who sells to both customers from the USA and customers from other countries, or an authorized Nikon Dealer who uses the old switcheroo to sell you a "cheaper" camera and then try to force you to "upgrade" to the "superior" USA model, since it is the only one in stock.


eAccelerator Issue - Cache Directory Empty

Question: Hoping someone can give me a hand with this.
I've recently installated eAccelerator 0.9.6.1 - On a CentOS LAMP server.
Had it working fine, using the /tmp/accelerator as the cache directory.
php.ini set up:

zend_extension="/usr/local/lib/php/extensions/no-debug-non-zts-20060613/eaccelerator.so"
  eaccelerator.shm_size="200"
  eaccelerator.cache_dir="/var/cache/eaccelerator"
  eaccelerator.enable="1"
  eaccelerator.optimizer="1"
  eaccelerator.check_mtime="1"
  eaccelerator.debug="0"
  eaccelerator.filter=""
  eaccelerator.shm_max="0"
  eaccelerator.shm_ttl="3600"
  eaccelerator.shm_prune_period="180"
  eaccelerator.shm_only="1"
  eaccelerator.compress="1"
  eaccelerator.compress_level="9"

php -v output:

PHP 5.2.12 (cli) (built: Feb 3 2010
  00:34:28) Copyright (c) 1997-2009 The
  PHP Group Zend Engine v2.2.0,
  Copyright (c) 1998-2009 Zend
  Technologies with eAccelerator
  v0.9.6.1, Copyright (c) 2004-2010
  eAccelerator, by eAccelerator with the
  ionCube PHP Loader v3.3.20, Copyright
  (c) 2002-2010, by ionCube Ltd.

I had to remove the cache directory as I was testing something. Remade it, re-set permissions and found that eAccelerator was no longer creating cache files within the folder.
I thought it might be down to ownership rights on the folder so chown'd it apache.apache and this made no difference.
I recreated the directory in /var/cache instead and editted php.ini to point to the new cache dir location, chmod'd, chown'd etc. and still eAccelerator is not creating any of the cache files in the directory (just empty).
Could someone suggest what I might be doing incorrectly here. I've read through numerous pages to try and troubleshoot the issue to no avail.
Any help appreciated.
Answer: eaccelerator.shm_only="1" means that it won't write to the disk.


Postal order has my name mis-spelt, can I still cash it?

Question: I've received a postal order, but the last letter of my surname is missing on it, can I still cash it?
Comment: Elsey Did it work?
Answer: You'll only know if you try. I suspect if you play it cool, it won't matter. If they point it out, just say "Oh, look at that! They must have mistyped it".
Answer: I've never had an issue with this sort of thing. Depending on your bank you can probably just deposit it in an ATM. I've never heard of a computer that even tries to read the "pay to:" section, let alone one that could figure it out if it was wrong.


What are the sources of the imagery for the Discworld resting on the backs of the four elephants and Great A'tuin?

Question: The turtle and elephant bit come from Hindu mythology. But the Vedas mention only one elephant and the world spins at the end of his trunk. I want to know if there are other mythologies Pratchett is specifically referencing here.
Answer: A few different cultures have turtles/tortoises as well as elephants as part of their creation myths.  As a combined image, however, it may have come down through the years partly from John Locke, a philosopher who used the example in his book An Essay Concerning Human Understanding, in a mocking way, of an elephant holding up the world, and a turtle holding it up.

He may have been mangling Hindu mythology, but he was using the example as a metaphor attacking the credibility of beliefs by examining their supporting evidence.
Answer: I believe he's borrowing directly from Hindu mythology.  The World Turtle mytheme is present in at least North American, Chinese, and Indian culture, while the World Elephant is more specific to Hindu mythology.
In terms of numbers, the elephants are at the compass points and so there are some multiple of four; for example in Ramayana the number is specified as exactly four:

deva daanava rakSobhiH pishaaca pataga uragaiH
puujyamaanam mahaatejaa dishaa gajam apashyata
And he that resplendent Amshuman beheld one of the four directional elephant of the earth which is being venerated by gods, monsters, demons, imps, vultures and serpents.

While in Amarkosha (PDF) there are eight (as with lords and planets):

airāvataḥ puṇḍarīko vāmanaḥ kumudo 'ñjanaḥ
puṣpadantaḥ sārvabhaumaḥ supratīkaśca diggajāḥ
Respective elephants associated to the eight directions

In The Folklore of Discworld (co-written with Jacqueline Simpson), Pratchett discusses the origin:

Further details of Hindu cosmology vary.  According to one myth, there are four (or eight) great elephants named the diggaja or diśāgaja, 'elephants of the directions', guarding the four (or eight) compass points of this disc, with a type of god called a lokapala riding on the back of each one.  But the oldest texts do not claim that they carry the world.  According to another myth, however, the world rests on the back of a single elephant, Maha-Padma, and he is standing on a tortoise named Chukwa.  Finally, it is said in yet another myth that the god Vishnu once took on the form of a vast tortoise or turtle (kūrma), so huge that Mount Meru, the sacred central mountain of the world, could rest on his back and be used as a stick to churn the ocean.  At some stage, though nobody knows just when, these insights began to blend, with the result that some (but not all) Hindu mythographers now say the world is a disc supported by four elephants supported by a turtle.

The book goes on to discuss the turtles all the way down idea, and the Chinese cosmic turtle (which contains the world), and the Thief of Baghdad's version:

ABU: Does the world have a roof?
GENIE: Of course! Supported by seven pillars, and the seven pillars are set on the shoulders of a genie whose strength is beyond thought, and the genie stands on an eagle, and the eagle on a bull, and the bull on a fish, and the fish swims in the sea of eternity.
Answer: I think he's solving the "Turtles All the Way Down" problem. It's not turtles all the way down, it's one turtle flying through space. Makes much more sense when you think about it.
Comment: "The phrase was popularized by Stephen Hawking in 1988." That was half a decade after the first Discworld book was published. I know the story Hawking relates is much older, but I still wonder whether Hawking could be influenced by Pratchett.
Answer: The idea of an elephant/elephants standing upon a giant turtle which supports the world is a part of numerous different cultures mythologies, mainly Hindu but this myth has similarities in other cultures such as China:

In Chinese mythology the creator goddess Nüwa cut the legs off the giant sea turtle Ao (鳌) and used them to prop up the sky after Gong Gong damaged the Buzhou Mountain that had previously supported the heavens.

In North America although elephants were not apart of the myth, the idea of the world residing on the back of a turtle is constant.
Although this myth has developed into the phase where it is believed that the world resides on the back of a varying number of elephants on one gigantic turtle I believe Pratchett was using the Hindu version of the myth. One interesting thing to think about is that in the beginning this mythology did NOT state that the disc the elephants were carrying was the world, some people believe that it was actually refers to the creation of the universe and the 'Milky Way's place in the galaxy.
Here are some websites that go into a little more detail on the Elephant/turtle myth.
Good Luck.
Explains the different myths and talks about the meaning behind them.
Another elephant and turtle myth
Comment: -1 Your first link looks *very* cooky / unreliable; your second link 404s for me now.  Frankly, this isn't an answer to the question anyway (since the question is where did *Pratchett* get the idea from) and would be better with just the first three paragraphs.
Answer: According to the author's notes on at least one edition of The Colour of Magic, the turtle originally came from hindu mythology, but the elephants were a more recent European addition.
Answer: According to this article from Tor, he was inspired by a combination of Hindu mythology and the "turtles all the way down" problem popularized by Bertrand Russell (which was inspired by the World Turtle mytheme).
From Tor:

The Discworld itself is, from an astrozoological point of view, founded on the exploration of a logical fallacy. Specifically, the infinite regress fallacy illustrated by the "turtles all the way down" cosmological myth, popularised in the West by the late philosopher and logician Bertrand Russell, but dating back centuries, with the earliest known references found in 16th century Hindu mythology.
And yet, most interestingly, Pratchett cuts straight to the core, does away with the infinite regress, and shows that fallacy is only false through lack of imagination. This is how we end up with the four Elephants, Jubul[sic], Jerakeen, Berilia and Great T'Phon, standing on the back of Great A'Tuin the World Turtle (sex unknown), who is not standing in turn upon an infinite tower of "turtles all the way down", but is far more sensibly swimming through space, towards an unfathomable destination all its own.
"The Tao of Sir Terry: Pratchett vs. Logic", J.R.H. Lawless, Tor.com, May 6, 2019

Turtles all the way down:

"Turtles all the way down" is an expression of the problem of infinite regress. The saying alludes to the mythological idea of a World Turtle that supports the earth on its back. It suggests that this turtle rests on the back of an even larger turtle, which itself is part of a column of increasingly large world turtles that continues indefinitely (i.e., "turtles all the way down").
"Turtles all the way down", Wikipedia

World Turtle mytheme:

The World Turtle (also referred to as the Cosmic Turtle or the World-bearing Turtle) is a mytheme of a giant turtle (or tortoise) supporting or containing the world. The mytheme, which is similar to that of the World Elephant and World Serpent, occurs in Hindu mythology, Chinese mythology and the mythologies of the indigenous peoples of the Americas
"World Turtle", Wikipedia
Comment: The elephant name "Jubul" appears to be a typo for "Tubul" in that article.
Answer: Look at old testiment descriptions of the world.
 The world is illustrates in the shape of a turtle.
Seven pillars support sheol and the firmament suspended in a fluid.
Under the influence this would easily morph into turtle.
Never got past the first 43 pages.


What are brass instrument "false notes" and how are they played?

Question: In @AlbrechtHügli's answer to Properties of a very low pitched natural horn?, "false notes" are mentioned. What are they, and how are they produced?
Answer: The wikipedia page which he linked in his answer describes false tones as follows:
"The fundamental is chromatically discontinuous with the lowest 2nd harmonic reachable on a three-valve instrument ... [False tones] have a pitch between the normal range and the fundamental."
So for example, a three-valve brass instrument in BBb (i.e. BBb Tuba) would have the note Bb0 as its highest fundamental (or pedal) note.  Its lowest playable first harmonic note would be E1 (with all valves pressed).  Then the notes B0, C1, Db1, D1, and Eb1 are between the instrument's lowest and highest notes, but are not really within its normal playable range.  These are referred to as false tones when played.
Adding a fourth valve which lowers the pitch by 5 semitones will add these five notes to the instrument's normal playable range, by extending the playable second harmonics down to B0.
As for the physics of playing these notes, I'll let someone more knowledgeable answer.
Comment: The lowest notes that a trumpet commonly plays are first harmonics.  The wikipedia page linked refers to the trumpet as a "half tube instrument" because it cannot easily play pedal tones, and attributes this property to it having narrow tubing.  Thus the false tone gap ends up below the trumpet's range entirely.
Comment: So the trumpet doesn't have "false tones". I actually opened this question [based on an answer](https://music.stackexchange.com/questions/108959/what-are-the-acoustics-of-brass-instrument-pedal-tones/109004#109004) to a question about pedal tones. Can you shed any light on that post?


How can I fix a broken desktop due to compiz?

Question: I try a effect in compiz. and it make my laptop show only a desktop bakcground. i have uncheck the effect. but my laptop still show only desktop background (no launcher, no dashboard, no date no time, etc. please help me
Comment: possible duplicate of [How do I reset my Unity configuration?](http://askubuntu.com/questions/17610/how-do-i-reset-my-unity-configuration)
Answer: I suggest before you play with compiz you open your dash and type "terminal".When you see the first terminal drag it to your desktop.That way when you lose your bars you can still get to a terminal.When you lose your bars open the terminal up and type in "unity  --reset" ,without the quotation marks though and hit enter.That worked for me everytime.Also I started noticing that when playing with compiz that if I unchecked unity plugin before I checked any other box,then checked unity plugin back when I was was done I had no problems.If your going for desktop cube do this,agree to resolve conflicts,disable left flip and desktop wall
Answer: to restore the desktop panels try this:

gconftool --recursive-unset /apps/panel
rm -rf ~/.gconf/apps/panel
pkill gnome-panel

Restore Desktop Panels in Ubuntu
Answer: please see link on how to fix - worked
Unity 3d no longer works after installing 12.04

issue is not 12.04, but an upgrade to  NVIDIA


What are the most respectable Bitcoin news websites?

Question: Which blogs or websites are the most respected in the community to bring everyone up-to-date with the Bitcoin-related news? I'm not talking about the forums, as the sheer volume of messages are overwhelming, nor am I talking about major news sites that occasionally mention Bitcoins. I'd like to know where should one go if they want the latests ins and outs of all things Bitcoin related in a digestible form.
Answer: Here are a list of blogs/sites I follow to keep up with bitcoin news:
reddit/r/bitcoin - user aggregated bitcoin links/topics, usually anything notable will be posted here.
Bitcoin Magazine - also available as an actual physical print magazine.
Cryptocoin News - mentions altcoins, but Bitcoin is most prominent
CoinDesk - a relatively new entrant to the Bitcoin news space
The Genesis Block
The Monetary Future - not exclusively bitcoin related but often covers bitcoin or related topics. This blogger (Jon Matonis)  is now a Forbes blogger and the content will typically appear on the Forbes site first.
Coding in my sleep - a personal blog  but more and more bitcoin related topics recently.
The Bitcoin Trader - excellent blog on bitcoin related topics. (less active recently (end 2012))
Bitcoin Money - another bitcoin blog.
Bitcoin Miner - bitcoin mining focused blog.
Bitcoin Watch - has a collection of links to the latest news along with exchange stats etc.
stuffexists.com - collection of lots of useful links.
Bitcoin Media - blog with articles mainly by Amir Taaki (genjix) (a Bitcoin developer)
blockchained.com - has a Top 16 Hot Topics from Bitcointalk.org (seems to use an algorithm to rank the most active current topics) as well as charts an some news links (was bitcoinx.com but that currently only has charts)
Bitcoin on Quora
Bitcoin on Twitter
The press sub-forum of bitcointalk.org is usually kept up to date with any press on bitcoin
Comment: might add http://coinie.com/  and  http://bitcoin.alltop.com/  to that
Comment: I wasn't aware of the coinie.com site - thanks for that.
Comment: For the last six months, I have been co-maintaining the [BitcoinBoard](http://www.quora.com/bitcoinboard) on Quora. This board is for sharing news and ideas related to the bitcoin economy, such as trading, mining, transactions and companies. Please feel free to post items that include analysis and critique rather than just an announcement of a new company or service.
Answer: Personally, besides the forums and SE, I'm following the sub-Reddit.
Answer: I tried to gather the most serious, interesting and long lasting ones on http://bitcoin.gw.gd/
There are many sections, but the most important one is http://bitcoin.gw.gd/-Bitcoin-News-  , currently including the rss feeds from more than 40 websites including betabeat, wired, CNN and many others.
This list is maintained and new websites are regularly added to the selection.
Answer: http://www.thebitcoinreview.com/
look at the Commerce and community setction for a complete list of these types of sites.
once you found the site you like best consider posting a review on TheBitcoinReview.com to help us weed out the good sites from the bad
Comment: You should consider proofreading your answer before posting it. It would be also nice if you provided a link straight to the section you are referring to.


What are some good reasons for why people make homemade pasta?

Question: What are some good reasons for people to make their own pasta? Does it make it cheaper? Does it taste any better?
Comment: Please don't mark the correct answer so quickly. It discourages other people from offering their experiences. Wait a day or too and your may get better answers
Answer: Pros

Any colour you like (even black). With some machines you can make rainbow stripes just like toothpaste tubes do
Any consistency you like, and more or less eggs, or just egg yolks. Add baking soda or Kansui to make stronger, more shape-able pasta (not more than 0.5% or it tastes soapy in a sauce)
Any flavour you like (herbs, spices, extracts, extra egg'y ...)
Any flour you like (wholemeal and buckwheat is my favourite)
Any shape you like, make lasagne sheets to fit your favourite lasagne pan, or make your own extruder dies (not trivial, but possible)
Easier and quicker to cook
Extruder machines give your arms a great work out
Fun to do with children, and educational
You control what ingredients go into it (more and more commercial pasta are including 'weird' ingredients for no reason I know of?)

The extruder you want :-)
Cons

Expensive to make if you account for your time (you should)
Flour is flour. The base tastes more or less the same
Large amount of time to make decent pasta, especially in tricky shapes
Pasta machines can be hard to clean
Special hardware (roller, drying racks, extruder etc.) required for anything but the basic flat noodles
Comment: @Thomas G. Mayfield It's a Bigolaro
Comment: You should only account for your time if you consider it a chore. If it's an intrinsically rewarding act to make your own food (which for many people it is) then your own time is donated, not spent. :)
Comment: Great answer – and damn I want that extruder! – but you don't mention taste. I usually make my pasta with eggs (mostly yolks) only and the taste has *so* much more body; it actually tastes of eggs and in the beginning when I started making pasta, I wasn't sure if I liked that or not, cause I wasn't used to it, but now I find it delicious. The consistency is also much more complex in a way, I think.

Also, when you're making lasagna, it's great that you can have the pasta layers fit the dish perfectly.
Comment: @citizen Taste is highly subjective. To me, even large amounts of eggs doesn't really change the flour taste (which I like). Making paste to shape we do too, will add that thanks!
Comment: Searching online I can't seem to find any products that match the old-fashioned extruder you show. Can you link to some product pages?
Answer: One of the best reasons to make fresh pasta is to make your own tortellini and ravioli.  It is simply impossible with dried pasta, since dried pasta no longer sticks to itself.  There are more variations of fillings than the standard "cheese" or "meat" that are otherwise unavailable if you only buy filled pasta at a grocery store.
Comment: +1 Good suggestion. Ravioli can be made by hand from dried flat lasagne sheets that have been soaked in warm water for few minutes. It works fine. But much easier with fresh pasta
Comment: The only 'real' reason to do it IMHO.
Answer: There are some of us that do this as part of a slow food / living simply / homesteading type thing.
Some of the main reasons for doing this:

Reduced packaging (eggs from the chooks, buy flour in bulk)
Reduced food miles
Focus on whole foods and reduced additives
The enjoyment of producing something with your own hands and involving your family in production
Ability to make things in larger quantities at a reduced or comparable price (I get my flour for free from a friend in exchange for the occasional pizza night)
Ability to home-make things which can be shared for free or exchanged for free with neighbours
Minimal or zero waste (flour bags can be re-used or composted), left over dough scraps and flour can be fed to livestock
Answer: Cheaper, customizable flavor (spinach, tomato, squash, etc), and in my opinion, far more delicious (ie fresh, different mouthfeel, and also because you control the ingredients you can use your favorite spices or veggies) than store bought. Only downside is the effort.
Comment: Could you elaborate on "more delicious"? I think there are some specific differences between fresh homemade pasta and storebought dried pasta.
Comment: @Jefromi, thx, I elaborated a bit.
Answer: With homemade pasta, you don't need any preservatives, and have complete control over what ingredients (quality, variety) are used.  You can add elements for a specific flavor (spinach is common, beet is something I'd like to try, I could see basil, and now @lemontwist has me curious about squash...), or substitute ingredients for specific dietary or health reasons.  I know several people who make their own pasta so they can make sure no salt is involved.
Fresh pasta is easier to cook, and doesn't require additional pantry space.  You likely have all the ingredients on-hand.
Comment: Preservatives are not a very typical ingredient in dried pasta...
Answer: It's better for sure, it tastes great and you can choose better raw ingredients and quality flour. Moreover you can add veggies, spices, eggs and customize pasta in many ways. You can also choose the best shape that suits your condiments.
Comment: I wouldn't say "better".  Certainly different.  It depends of the application.