Constructing an eigenbasis of graph states for a set of stabilizers

Question: The stabilizers of a given graph all commute, thus it must be possible to diagonalize them simultaneously. If I start with one graph state and write down all its stabilizers is there an easy way to derive a complete eigenbasis of the stabilizers in terms of graph states?
Answer: If you start with one graph state, which is an eigenstate of stabilizer (each of which comprises an X tensored with a bunch of Zs), then the other eigenstates of those stabilizers are the original state acted on by Z rotations (take all possible combinations). To see this note the commutation and anticommutation relations between a tensor product of Zs and each stabilizer.
Consider a stabilizer of the form $K_n=X_nZ_iZ_j\ldots Z_k$, i.e. a graph-state stabilizer with a Pauli $X$ on qubit $n$, and a bunch of $Z$s on some other qubits (related to the graph structure). By definition, the graph state satisfies
$$
K_n|\psi\rangle=|\psi\rangle
$$
for all $n$. Now, let
$$
|\Psi_x\rangle=\left(\bigotimes_{i=1}^nZ^{x_i}\right)|\psi\rangle,
$$
for $x\in\{0,1\}^n$, a binary string. If we apply the stabilizers to such a state, we get
$$
K_n|\Psi_x\rangle=K_n\left(\bigotimes_{i=1}^nZ^{x_i}\right)|\psi\rangle=\left\{\begin{array}{cc}
\left(\bigotimes_{i=1}^nZ^{x_i}\right)K_n|\psi\rangle & x_n=0 \\
-\left(\bigotimes_{i=1}^nZ^{x_i}\right)K_n|\psi\rangle & x_n=1
\end{array}\right.
$$
Thus, every $|\Psi_x\rangle$ is an eigenstate of every stabilizer, and with a different pattern of $\pm 1$ eigenvalues (and must therefore be mutually orthogonal).
While it must be the case that the different states $|\Psi_x\rangle$ are orthogonal, I think it's useful to think about this in terms of the way that the graph states are created. Remember that $|\psi\rangle$ is created from qubits in the $|+\rangle$ state and then have controlled-phase gates applied between them. Now, if I evaluate $\langle\Psi_y|\Psi_x\rangle$, think of this as a calculation
$$
\langle+|^{\otimes n}CP\cdot Z_{x\oplus y}\cdot CP|+\rangle^{\otimes n}
$$
where $CP$ represents the collection of controlled phase gates. Pauli $Z$ commutes with controlled phase, which means we can bring the two CPs together and annihilate them, leaving behind
$$
\langle+|^{\otimes n} Z_{x\oplus y}|+\rangle^{\otimes n}.
$$
Given that $x\neq y$, there is at least one $Z$, and we know $\langle +|Z|+\rangle=\langle -|+\rangle=0$.
This way of thinking gives another way of describing the basis of graph states: prepare each qubit in either $|+\rangle$ or $|-\rangle$, and combine with controlled-phases. Each different choice of $\pm$ gives a different graph state in the basis.
Comment: Ok, this is cool as independently I got more or less the same solution, although it took me much longer than you :-)
Comment: How do we get to $ |G><G|=1/2^n \sum_{\sigma\in S}\sigma$ where is the S is the set of stabilizers.
Comment: @upstart This seems like a new question....
Answer: I'm not sure I understand the question, since this seems quite straightforward.
Graph states are Clifford states, so for a state on $n$ qubits, the set of stabilizers has $n$ generators looking like
$$i^k P_1\otimes\ldots\otimes P_n$$
where $k\in\{0,1,2,3\}$ and the $P$'s are Pauli $X,Y,$ or $Z$ operators. (For graph states, these stabilizers look like $\{X_v Z_{\text{Nbhd}(v)} : v \in V\}$ )
Each Pauli has two eigenvectors. If we choose one of them and call it $|\psi_i\rangle$, and call its corresponding eigenvalue $\lambda_i$, for each $P_i$, then $|\psi_1\rangle\otimes\ldots\otimes|\psi_n\rangle$ will be an eigenvector of the stabilizer with eigenvalue $i^k\prod_i \lambda_i$.


Passing parameter in flex function

Question: I have several TextInputs in a certain form which have been assigned id in an incremental order. For example:
<s:TextInput id = "index1"/>
<s:TextInput id = "index2"/>
<s:TextInput id = "index3"/>

Based on certain conditions I select the text from the corresponding TextInput and pass the value (index#.text) into a function
 foo(var index:String)

If I had just one of the TextInput I could have used:
foo(index1.text)

Can someone suggest how I can pass the textInput using its id.
Thank you.
-H
Comment: I think you need to elaborate on what you mean by "certain conditions." This looks like the kind of thing I would use events for, but I can't be sure what you mean here.
Answer: I plus one the request for 'certain conditions'.  You post alludes to the fact that you can't access the component by name, so I'm writing the rest of this based on that assumption.
To access the values of a component and pass parameters of that component into a function you need an identifier, or link, to that component.  It is easiest if you use the components name.  But, that is not always possible.  For example, the Flextras Calendar component creates, and displays, the days of the month.  Depending what month is displayed, there may be 28, 30, or 31 days.  It is not practical to access them by a unique name.
this is a similar situation in a ListBased class.  You won't know, at compile time, how many itemRenderers you're going to need or have on the screen at one time.
One way to approach this is to have an array of the relevant objects (dayRenderers, itemRenderers, or in your case TextInputs).  When doing processing you can loop over the array and process the element.  Something like this:
for (var x = 0; x<objectArray.length; x++){
   foo(objectArray[x].text);
}

If that is not desirable to you, for whatever reason, you can loop over the children of a container doing something like this:
for (var x = 0; x<container.numChildren; x++){
  var object : Object = this.getChildat(x);
  if(object is TextInput){ foo(object.text) }
}

Functional, but it can be a bit tedious at times.  It really depends what you're trying accomplish.

Passing parameter in flex function


How much peat moss would I need to lower the ph of my soil

Question: I had my soil tested.  The ph is 8.2. What is the best product to lower the ph.  I'm reading about sulfur, aluminum sulfate and peat moss.  Peat moss looks like the best bet but how much do I need to add?
Comment: a hard question to answer without more details, type of soil--clay or sand or ??  location in the world,  what does grow well there?
Comment: Another factor to consider with pH is where in your property the soil sample(s) was taken? Was it near a building foundation? A concrete wall or driveway? A retaining wall? These are all sources of alkalinity that can affect sampling for pH.
Answer: Edward J. Plaster, author of Soil Science and Management, 5th edition, recommends using sulfur to acidify the soil and not peat moss to lower pH. He states that peat moss is a temporary solution to the problem because as it decomposes its pH-lowering ability diminishes to zero and the soil's pH will then return to its original figure. OTOH, if you have clay soils then the peat moss will at least add some organic matter to the soil and improve its drainage. You'll still have high pH, but you'll have better soil for gardening.
If you want to follow Dr. Plaster's recommendation, in the work I've cited (p. 247) he shows a chart that recommends the amount of sulfur need to lower the pH by 1.0 over two different areas. Here are the figures in both Imperial (and, I hope, correct) metric amounts and areas.
Imperial
Pints per 100 square feet
Sand - 1.33 pints
Loam - 4 pints

Pounds per acre
Sand - 725
Loam - 2200

Metric
Liters per 9.3 square meters
Sand - 0.63 liters
Loam - 1.9 liters

Kilograms per acre
Sand - 329
Loam - 1000

1 acre = 0.405 hectare, so 1 hectare = 2.47 acres, yielding (I hope):
Kilograms per hectare
Sand - 812.63
Loam - 2470

No matter which measuring system you use, this is A LOT of sulfur. If planting a vegetable garden, you'd probably be better off using raised beds where you can more easily control pH and if planting a landscape, you'd be better off following the adage 'right plant, right place' and planting only plants that like higher pH soil.


How to take a snapshot of addresses and balances of all normal addresses?

Question: How would one take an addresses and balances "snapshot" of all 6,086,374 normal addresses at block number 4293752?
Comment: Current and complete seem mutually exclusive; you can maybe have one, but you can't have both. The blockchain is constantly being appended to. A further complication is that there is (often?) no one canonical chain. There can be several competing chains at once, though only one chain will win in the end. By the time we find out which one has won, there are new forks on top of the once-winning chain.
Comment: Understood, allow me to restate with clear precision - "How would one take an addresses and balances snapshot of all 6,086,374 normal addresses at block number 4293752?
Answer: I think the OP means complete to the currently accepted last node that was mined a little while ago.
One way would be to build your own explorer
- run a geth node
- attach a console and use the web3 JavaScript library (https://github.com/ethereum/wiki/wiki/JavaScript-API)
- get each block using getBlock
- get each transaction and find the from and to addresses
- get the balance of the address (https://github.com/ethereum/wiki/wiki/JavaScript-API#web3ethgetbalance)
Of course we would likely want to limit this to wallet addresses or account addresses.  I don't see how we can know that...still looking.
Answer: Getting the balances is easy, there's an api web3.eth.getBalance. You can specify from which block do you want the balance.
The hard part is collecting the addresses. If you do not want to use an external api like etherscan then you have to build a database processing all  transactions in the blockchain registering sender and receiver.
You will still be missing accounts created by "internal transactions". For that you have to use low level trace apis from geth/parity.


Filter plugging from co2 pressure

Question: I have been fermenting in a 42 Blichmann and when transferring the beer I plug the 1 micron filter with yeast even though I have
dumped most of trub and yeast during the 3 weeks of fermenting.  I use 5 lbs pressure from the co2 tank.  I did not have this problem when siphoning from a secondary carboy.  Does the pressure stir up the yeast?
The outlet is well above the settled yeast.
Answer: If the beer is cloudy to the eye a 1 micron filter will clog very quickly.
The beer must not have completed fining before filtering.
In the future pull a sample before starting to filter to make sure it's completely crashed out first.

Filter plugging from co2 pressure


Can "drive someone home" be used when the vehicle is a motorbike?

Question: Can "drive someone home" be used when the vehicle is a motorbike? Can I use "ride someone home" with the same meaning as "drive someone home"?
Comment: "Ride someone home" implies you're riding on their back, or something like that. It could also be taken as a sort of unintentional sexual innuendo. The phrase you're looking for is "give someone a ride home".
Comment: ... which still can be taken as an innuendo.
Answer: Well the original definition of "to drive" was to compel something to move by force.
For instance, the phrase "I drive my friend" could have an entirely different connotation if you add "to succeed in sports". Now you're driving him morally, not within a car.
The word drive is, in this way, very flexible. The original definitions extends to metaphors and analogies, meaning any time you're influencing something towards a certain ends you can consider it driving.
Therefore, yes- you can grammatically say you "drive you friend" on a motorbike.
The reason it sounds strange is because any time you're talking about a motorbike you expect to hear the word "ride", not "drive". This is simply a common cultural pattern. In your specific case, however, saying you "ride someone home" is not the same as "drive someone home".
"To ride" is to be in or on something that is moving. Thus, if you "ride your friend home", you're on your friend's back and riding him like a horse =)
If you want to use the word ride, try:
"I gave my friend a ride home", or "I rode my friend home on my bike".
Note that the second is acceptable because the preposition "on" clearly identifies the direct object (the object being ridden), which leaves the other noun ("my friend") to be the indirect object - one who is affected by the act of you riding the bike.
Comment: I don't think a native speaker would say "I rode my friend home on my bike."
Comment: @Martha: Anecdotally... in rural northeastern USA I've heard "I rode him home," "Can you ride me home?" etc. quite a bit without speakers or listeners indicating there's any innuendo or any meaning but "give a lift home in your vehicle". Native speakers do say it in some places!
Comment: Martha: I don't believe I've ever heard it used natively, either, but it's grammatically correct and I was simply trying to construct a correct sentence with a structure closely approximating his. "ride someone (my friend) home".
Comment: @Martha, @steven_desu Have a look at this [ngram for 'ride me home'](http://ngrams.googlelabs.com/graph?content=ride+me+home&year_start=1900&year_end=2000&corpus=0&smoothing=3) as well - it's not common but there are a number of uses involving cars and bikes. (I found it too hard to come up with a phrase like "ride him home" that wasn't full of horses so I didn't try looking for that one...)
Answer: I would describe this situation as 'giving someone a lift home'.


Is it sunna to sit around a white cloth after magrib prayer?

Question: Most African muslim places White cloth in the mosque and sits around it to worship and mentioning the numerous name of Allah after magrib prayer is been done. My question is: Is it a Sunna?
Comment: what is the purpose of the white cloth?  do you got a picture as example?
Answer: All perfect praise be to Allah
While it is still unclear what they do, but it seems like a practice(of a group) in our country where after each prayer, people loudly repeat KALIMA and than darood in the end, which is a biddah. So, if they cannot provide any supporting evidence for what they are doing. It is in the same category.
There is a whole list of SUNNAH DUA(sayings) after prayer which we should say and they are enough for us. I don't know why people have started prefering THEIR zikr on sunnah zikr.
EDIT: I thought i should include a hadith which covers a similar happening in masjid al-nabvi. Hope it will be helpful.

al-Darimi in the Muqaddima of his Sunan narrated from al-Hakam ibn
  al-Mubarak who narrates from Amr ibn Salima al-Hamadani:
We used to sit by the door of Abd Allah ibn Masud before the Morning
  Prayer, so that when he came out we would walk with him to the mosque.
  (One day) Abu Musa al-Ashari came to us and said: "Has Abu Abd
  al-Rahman come out yet?" We replied No. So he sat down with us until
  he came out. When he came out, we all stood along with him, so Abu
  Musa said to him: "O Abu Abd al-Rahman! I have just seen something in
  the mosque which I considered wrong, but all praise is for Allah, I
  did not see anything except good in it." He inquired: "What is it?"
  Abu Musa replied: "If you live you will see it. I saw in the mosque
  people sitting in circles awaiting the Prayer. In each circle they had
  pebbles in their hands and a man would say: Repeat allahu akbar a
  hundred times. So they would repeat it a hundred times. Then he would
  say: say la ilaha illallah a hundred times. So they would say it a
  hundred times. Then he would say: say subhanallah a hundred times. So
  they would say it a hundred times." Ibn Masud asked: "What did you
  say to them?" Abu Musa said: "I did not say anything to them. Instead
  I waited to hear your view on it." Ibn Masud replied: "Would that you
  had ordered them to count their evil deeds and assured them that their
  good deeds would not be lost!" Then we went along with him until he
  came to one of these circles whereby he stood and said: "What is this
  I see you doing?" They replied: "O Abu Abd al-Rahman! These are
  pebbles upon which we are counting takbir, tahlil and tasbih." He
  said: "Count your evil deeds instead. I assure you that none of your
  good deeds will be lost. Woe to you, O Umma of Muhammad, sallallahu
  alayhi wa sallam, how quickly you go to destruction! Here are your
  Prophet's Companions available in abundance (mutawafirun). And there
  are his clothes which have not yet decayed and his bowl which is
  unbroken. By Him in Whose Hand is my soul! Either you are following a
  Religion that is better guided than the Religion of Muhammad
  sallallahu alayhi wa sallam, or you are opening a door of
  misguidance." They said: "O Abu Abd al-Rahman! By Allah, we only
  intend good!" He said: "How many are there who intend good but do not
  achieve it. Indeed Allah's Messenger said to us: A people will recite
  the Qur'an but it will not pass beyond their throats. By Allah! I do
  not know, but perhaps most of them are from among you." Then he left
  them. Amr ibn Salima said: We saw most of those people fighting
  against us on the day of Nahrawan, on the side of the Khawarij.

(there are also many other isnaad of this hadees)
Now i should also have to mention that their is a group of people who does not agree to this defination of biddah which is used in this hadees. for details on defination of biddah you can refer to this question and tits answers.
Allah knows best
Comment: Here we go again the answer is derived from the definition you have of bid'ah.
Comment: @Kilise It must be clear that a group of people do such things, and it is obvious that they are doing such thing is based on SOMETHING or some DEFINATION of theirs od something, in this case biddah. So, what you want to do with this kind of questions now? ban them or their will be answers like this.. Obviously one will answer with what he thinks is right.
Comment: I am at the moment not saying that it's either bid'ah or not. As you might have noticed I asked him so questions because much context is missing. The answers has to be objective and not subjective. You can't answer a question with super confidence when there are different of definitions of the term you are answering on. That's wy it has to be objective and not subjective.
Comment: meaning i should have mentioned that their are 2 opinions about it?? Thats fair, but i can quote a hadith here which is an incident of abdullah ibn umer RA that eh saw some people doing such thing and he said it is biddah... that will be appropriate too. meanwhile i will be glad if you can suggest some edit
Comment: Yes, that's exactly what I mean. Also if you quote a hadith like that it might also be good to explain how the scholars (that differ on the definition of bidah) have interpreted that hadith. You understand? This will give the most fair answer as possible. In the end time, we all differ on what we think is the right definition, that is OK. This is so we muslims stay together even if we disagree.
Comment: disagreement is not an issue, disagreement just on basis of personal reasons even when one's heart says the other opinion is right, that is the problem. Anyway, you can mention any edits in my answer. I will be more than happy to include them after review. Jazakallah


Looking for 26 x 1.6 tires is there an alternative.

Question: I have an old bike that my wife would like to get back riding now that we are near a bike trail. The tires on the bike are dry rot and I need to replace. Tire size is 26 x 1.6 having troubles finding a match. Any alternatives?
Comment: A thing to beware of is that 26-inch tires with a *decimal* width (eg, 1.75) are generally interchangeable between (reasonably close) widths, but 26-inch tires with a *fractional* width (eg, 1-3/4) are not -- they all have different "bead circle diameters".  [Sheldon Brown](http://sheldonbrown.com/tire-sizing.html) explains this at some length.
Comment: 26x1.6 tires are still fairly common. Ask your bike shop or go online. You can get another 26x something else tire, provided the frame has the clearance (though ideally, you'd choose something that wasn't too big or small compared to the width of the rim, all of them should work on that rim).
Comment: Welcome to [bicycles.se] @Bob. There are many similar questions on the site; they can be found under the [tag:tire] tag, or at the right hand side of this question of you're using a full size computer screen.
Answer: The 1.6" width is oddball, but you don't have to use 1.6" exactly. The common sizes in that area are 26x1.5 and 26x1.75. The frame will probably have clearance for both, although 1.75 is obviously a little larger so you'll have to check if you want to go wider.
Answer: The late great Sheldon Brown's web site has a page on tire sizing that says your wife's tires have a 559 mm "bead seat diameter" (BSD).  The BSD way of measuring tires is unequivocal and cuts through a lot of the confusion with tire sizes, although the clerk at your local bicycle shop probably understands 26 x 1.6 better.
Anyway, Sheldon's page goes on to say that tires sized anywhere from a 26 x 1.00 to a 26 x 5.0, where the number after the x has a decimal point and not a fraction, should fit the rim.  Of course the tire also has to be able to squeeze between the brake shoes and not rub on the frame, so some of the wider tires in that range, such as a 26 x 5.0, probably would't work.
If you take the bike to your local bike shop, meaning a locally-owned shop, not the bike department of a department store and not a store that's part of a big chain, then they should be able to help you.  Bring the whole bike so that they can test that the tire fits between the brake shoes and doesn't rub on the frame.  Good luck, and happy riding!


How would you evaluate object oriented design skills?

Question: what kind of insights or questions would lead you to determine a person's OOAD skills.
Comment: Ask them if they dot their i's.
Answer: You could show some half-assed OO design of a simple problem, and discuss what it does, what's good and bad about it, whether it's flexible enough, what could be improved, and how.
If you need to get the discussion going, ask what the person thinks about some aspect of the code, but not with a leading question.
Important is to remember that the discussion is important, not that you knew the answers beforehand. Any decent developer should be able to point out something about the code that you didn't even think of before.
Comment: i like this method of interview where it is a discussion rather than a Q&A.
Answer: Discuss an open ended design problem with the person. See how s/he proceeds to build a model of the system, what kind of questions are asked, how the design changes in response to new information.
A great example - mentioned by Steve Yegge in one of his blog posts - is to ask the person to come up with an object model for XML.
Comment: @bronzebeard - Here you go - http://sites.google.com/site/steveyegge2/five-essential-phone-screen-questions . He actually talks about OO modelling HTML - but I think XML can be a tougher version of the that question :)
Comment: Could you give me the link :)
Answer: Having a good knowledge of all the most popular design patterns can prove the candidate actually searched for solutions to his design problems.
Being able to discuss them and know when to apply them or not is a good indication that he understands them.
Asking him for example usages in his past experiences may also helps.
Comment: However, you can have a knowledge of design patterns and never have heard of the concept. I had been using things like chain of responsibility, observers, and controllers long before I knew that they had names. Be careful not to assume that because someone doesn't know the name of a pattern he can't use it competently.
Comment: That's a test of knowing how overloading works in C#, but hardly a test for OOAD design skills.
Comment: Your are perfectly right. I read your question too fast I change it.
Comment: @Michael: yes that's certainly why it's better to first ask how to solve a certain problem, then talk about the actual name of the pattern. I know many people using the strategy pattern everyday and that don't know it is called like that. They just "created" it by just thinking, like the original group of four did. The difference is that the latter wrote a book on the subject.
Comment: Note, the Gang of Four got the patterns from seeing OO code used in other projects. They by no means take credit for any of the designs, only in recognizing them and describing them in a consistent way.
Answer: Don't give a vocabulary quiz.    "Define Inheritance"  or "name 3 features of OO design" are questions that won't tell you anything about the skills of the individual, only how long since he/she last read a textbook.   I've met several great programmers who use these skills every day, but would choke if asked to give the formal definition.
Answer: Will ask him to write down the business objects, classes, and interfaces/methods for a room or any other virtual entity
Answer: If possible, ask for sample code.
Otherwise, find some procedural code to use as an example (or some poorly designed OO code), and then ask them how they would redesign, generalize and improve it. Be sure the program has extra context, so that the redesign can be meaningful.
Ultimately what you are testing-- design-- is subjective. Thus, your evaluation should be open-ended to allow for several possible good solutions, and not just a single one. Then, think about possible changes to requirements that would force an interface change: How do they handle it?
Answer: Read the book Head First Design Patterns. All the examples in the book start with an Object Oriented problem and than end up in the Design pattern. They also tell why certain OOP's concepts will achieve limitted results and why certain are better than others.
Even though a Design Pattern book this book is full of OOP's problems :-)
Comment: I donno about this, cause all the examples in the book are specifically towards one Design Pattern or the other. If you have just enough theoretical knowledge you would be able to figure it out and that doesn't reflect pragmatic application
Answer: Start off simple: what's OOP all about?
You could start off by asking about the basic premises of OOP: abstraction, polymorphism, inheritance and encapsulation. Good food for thought to get them warmed up.
Give them a problem
Next, present them with a problem that is likely to involve patterns. It's not necessary to name or use patterns, but their approach will likely yield some if they've got experience in the area.
Perhaps dynamic text input validation. You'd like to be able to validate the input character by character to see if it's a valid date, time or date and time in ISO8601 format. You get a copy of the input string each time a key is pressed and you can return a
boolean to indicate if the text remains good in at least one of the formats. Ask them to talk through and sketch out a design using OO design principles.
By the time you've finished chatting about

Controller (that thing that fires the change events and evaluates the responses),
Observer (the validators respond to the change events),
Strategy (each validator represents a different way of determining if the input is valid),

then you'll have a pretty good idea if they understand OOD.
Give them the same problem again, but this time ask for a different design
Now, ask them to redesign the system without using an Observer pattern (if they mentioned it) - they may choose to go for a Chain of Responsibility approach or perhaps a Command pattern. You don't really care which, you know that they have a reasonable grasp of the principles involved.
Even if they don't go for a pattern based approach, just listening to the way they attempt to break the problem down into its related functionality will yield the results you're after.
Answer: I tend to pick a real world scenario, something well known to anyone† and ask them to identify the entities; the actors involved; what interactions there are between them; where common features could be abstracted; what properties need be considered.
Yes, you could ask them to sit down and draw UML, yes you could ask them searching questions on some OOP implementation specifics to see if they can "hit the ground running".
But what an employer really needs within their team is a mind that understands the concepts involved and can apply them to whatever turns up.  Specifics can be learnt quickly, when concepts are embedded.

† Deep familiarity and an absence of a connection with code help: A family's use of a bathroom in the morning; cooking dinner; a bus route to work; the assembly of a car.
Answer: Something that seems to work rather well, and actually only takes a few seconds: ask them to design an object model. It doesn't matter for what. It can be absolutely trivial. In fact, it probably should be trivial, to not drag out the test unnecessarily.
If the first thing they write is an object, they are already ahead of 99% of their peers in their understanding of OO. If the first thing they write is a class, kindly ask them to go out and send the next candidate in, and contemplate about why it's called OOP and not COP.
Comment: While I understand what you mean I think I might be a bit careful about taking this to literally.  When I'm 'free thinking' design solutions I tend to use UML class notations even if that isn't what I really mean by my diagramming.


Upgrading Joytech hub from 8 speed to 10 speed

Question: I have a Joytech hub and I'm planning to upgrade from 8 to 10 speed. With my Joytech rear hub, do I need to change my hub first and does my hub support 10 cogs?
Comment: There is more than one joytech hub.
Answer: Provided the hub has a Shimano/SRAM compatible cassette body you should be able to upgrade to 10 speed with your existing hub.  Campagnolo 8 speed cassette bodies are incompatible with Campy 10 speed cassettes so if you are running Campy you will need a new hub.
Comment: @batman for a given speed... there are no differences in cassette spacing between road and mountain.  The difference is the gear range


The amount of texts Irene sent in A Scandal in Belgravia?

Question: In the BBC Sherlock series, in A Scandal in Belgravia, Irene Adler's texts are shown on the screen near the end as she scrolls through them. But, if her texts are counted there are 16 while on the first day of her texting Sherlock, Watson states, "Fifty-seven of those texts – the ones I've heard." Has there been a mistake?
Comment: Why do you think all her texts were shown? Could ther not be 42 others she sent which were not shown?
Answer: Obviously we don't see on screen every single instance when Doctor John Hamish Watson heard Irene's text alert. It's also similar to how we don't actually see every single murder Sherlock has solved. But when little Archie says, "Have you solved any murders?" And Sherlock replies, "Yup, loads." We don't just assume that the only murders he could have solved are the ones we saw on screen.


Why is successive decomposition of a signal performed only on low pass component?

Question: The question says it all. In typical (wavelet-like) decomposition of a signal, why is only the low pass component chosen for successive decomposition ?
Answer: Wavelets decomposition separates out the details/fluctuations/high-pass information from the image or signal. At each step details are separated out from the remaining of the signal. The processing is therefore only applied on the coarse part not the part that already has the details.
Answer: A filter bank is just one specific implementation of the wavelet transform. Typically wavelets are motivated and defined differently, namely as a family of (orthogonal) basis functions that are generated from a mother wavelet by translation and time scaling. It turns out that such a family can only be an orthogonal basis if the time-frequency plane is divided into a so called dyadic grid, pictured in this link. The resulting basis transform is then called the discrete wavelet transform.
This specific discrete wavelet transform comes with a fast algorithm, realised by recursive high and low pass filtering and downsampling. The first high pass filter creates the top most row of coefficients in the dyadic grid. The low pass component still contains the full information required for all the other rows. Taking the low pass component through the high pass filter again generates just the next row, and so on.
So it's helpful to not think of the filter bank as the defining property of the wavelet transform but just as a fast algorithm that returns the right result.
That said, there are approaches to adapt the time-frequency decomposition to the signal content, grouping and subdividing filter bank bands as it appears useful. Mathematically, those approaches cannot be understood in terms of wavelets however.


Why are scores and points in multiples or 5 or 10

Question: In a lot of games or gamification mechanics the point given to user are in multiples of 5, 10 or 100 and your score is always divisible by this number. Why?
Comment: As to the reason it's 5 or 10 and not some other multiple, I'd say it's probably because we have 5 fingers per hand and so those numbers are pleasing to us.
Comment: It's just more fun that way :)
Comment: There are actually two questions here:  1 - Why use decimal ? 2 - Why use bigger numbers rather than smaller numbers ?
Comment: I used to love playing pinball where the scores went up in thousands and tens of thousands. The resulting scores (in the millions) were meant to make you feel like you'd achieved something fantastic - Although I'm not sure how true that was.
Answer: Having worked on this kind of thing before, I can say that I chose multiples of 5 because it's super easy for people to get a gist of how the value of one achievement (for example) compares to another. If I'm looking at a list of achievements and I see:

Achievement A - 10 points
Achievement B - 20 points
Achievement C - 5 points
Achievement D - 100 points

It requires almost no thought to see that A is worth half as much as B and D is worth 10 times as much as A. If I'm looking at:

Achievement A - 2 points
Achievement B - 4 points
Achievement C - 1 point
Achievement D - 20 points

It's not so obvious. The reason this matters is because people tend to use these scores as an informal guide to how difficult the achievement is going to be. They can assume that an achievement that offers twice as many points as another will be roughly twice as hard.
Comment: Could you elaborate on this a bit? Why do you think it requires less effort to determine that 20 is two times 10 than to determine 4 is two times 2? Comparing A to D involves a change of order in magnitude in both cases. Why should the first set of achievement values be easier than the second, then?
Comment: Because one is a change in order of magnitude by the power of 10, the other is a change in order of magnitude by the power of 2. Since the decimal numbering system is base 10, we're very accustomed to calculating in powers of 10, not so much powers of 2. Contrast this to a programmer who may very well have no problem calculating in powers of 2. For example, how quickly could you work out that 128 is a base 2 order higher than 64, versus working out that 1000 is a base 10 order higher than 100?
Comment: I should also mention that the four examples I gave were just that: examples. My point was that a fine grained points system ends up with a lot more complicated comparisons than a "multiple of 5" points system.
Answer: My initial thoughts are that larger multiples give a greater sense of progression and success (would you rather have 100 points or 10?), while I imagine it's easier to count in fives and tens than it is in sevens or nineteens (therefore easier for adults who want to relax, and children).
I can't speak to the actual reasons used in the design of all games of course.
Comment: To expand on your easier to count comment; our numbering system is base ten, thus we think in tens. Reducing mental calculation, especially in games, is a plus, so when representing scores it's easier to use ten and an easier fraction of that number, five. I think why you see fives and tens and not ones is because of exactly what you wrote in your answer; a greater sense of progression.
Answer: We've been using decimal system(base 10) for quite a while now. Everything from currency to measurementa is in decimal system. Remember Roman numeral systems?
Also evolutionarily, decimal system is easy because we have 10 fingers. Easy to count. And hence gone with easy
Answer: I think you'll find that games where such steps are used are pretty much oriented to demographic groups (e.g. teenagers) where really big numbers are more satisfying than small numbers, even though they represent the same continuum.
Answer: I saw this habit mostly in kids game, because kids can be attracted to bigger earned values in comparison to lower values.
also i saw that kids compares the earned points in a game with other played game! for example he earned 20 points in a game with 5minutes playing and earned 2points after 15minutes playing other game.so i think kid will be attracted to first game


How did The Doctor and Clara escape his timeline?

Question: In the last episode of season 7, The Doctor goes into his timeline to save Clara. It ends when they see his war regeneration and Clara faints. Did I miss a special episode between that one and the 50th anniversary special? Because they never explained how they escaped his timeline.
Comment: He waved his Sonic Screwdriver, of course..
Comment: Probably after having read the idea somewhere, I did think that maybe they haven't escaped his timestream yet — that the adventure we saw in the 50th anniversary special occurred prior to the 12th Doctor visiting Trenzalore. However, as he mentions visiting Trenzalore near the end of the special, I don't think that theory works.
Comment: Not a real answer, but note that the trailer for the 2013 Christmas special mentions Trenzalore, so it seems as if we will return there then.
Answer: Presumably, the Doctor led her out. He was shown to be immune to the scattering effect that the Great Intelligence and Clara experienced, and it is his own personal time-tunnel, so one would assume that it would be familiar to him.
Before entering the timestream, the Doctor says to Vastra, Jenny, and Strax, "If I don't make it back, and I might not…," which implies that there is only a chance that he will not return (which is referring to the possibility of the timestream collapsing in on itself as a result of the paradoxes caused by him being in it).
Comment: I think you're spot on. At the end of *The Name of the Doctor*, when they see the War Doctor, The Doctor says to Clara something along the lines of "Come on, we need to get back." I'm pretty sure the implication is that he subsequently got them out of the time stream. It could have been clearer, but the main focus of that scene was **OMG LOOK A HITHERTO-UNKNOWN PRIOR VERSION OF THE DOCTOR PLAYED BY THAT GUY FROM ALIEN, GOOD GOLLY GUMDROPS** (which is my personal catchphrase suggestion for Peter Capaldi's Doctor).
Comment: I have long been asking myself this question but I think his timeline isn't collapsing. As I can see it, him inside his own timeline it's just him. I'm getting closer to this ep to rewatch it, so I may be wrong.


Mixing water and oil in microgravity outside of a container

Question: What would happen if I  where to mix water and oil in a vacuum in microgravity  where the temperatures  were low enough so that the oil and water remain liquids also, the mixture is not inside of a container.
 I would expect the water and oil two separate into two blobs, but wouldn't the London dispersion forces hold the two blobs together?
Comment: https://www.google.com/amp/lightyears.blogs.cnn.com/2011/10/18/oil-and-water-in-microgravity/amp/
Answer: An experiment similar to this was carried out using a free-fall drop shaft to provide the microgravity environment in Japan in 2000.
From the abstract of the publication$^1$:

An experimental study was performed to obtain the detailed information needed to provide a deep understanding of the combustion process and the secondary atomization of an oil-in-water emulsion droplet. The oil-in-water emulsion, which consisted of n-hexadecane as a base fuel, distilled water, and a trace of surfactant was tested. Photographic observation and temperature measurements were made of the suspended emulsion droplet during the heating-up and combustion processes under microgravity. The primary attention was toward the phase separation in the droplet, and the time histories of droplet temperature and the amount of water in the droplet, during the period of time prior to disruptive microexplosion. The results showed that the separation of the base fuel and water as well as their agglomeration and coalescence occurred with the lapse of time. The increase in the droplet temperature resulted in phase separation, and the formation of a single water droplet enveloped by a shell of the base fuel, prior to the microexplosion.

Interestingly, the phase separation was attributed to the increase in droplet temperature. It's my guess that the heating increased the rate of separation, but that given time the final result of "the formation of a single water droplet enveloped by a shell of the base fuel" would have taken place, and I think this would be the result of the situation described in the question; that van der Waals forces between the oil and water would prevent them from separating into two separate balls of liquid. The stronger hydrogen bonds of water were likely the reason for water forming on the inside of the droplet, and I would expect the same to happen in the case described in the question.
Summary, TL;DR:
Based on the results of the drop-shaft microgravity experiment described above, I would expect similar results for an experiment as described in the question. There should be an inner ball of water held together by hydrogen bonding, surrounded by an oil shell held together, and to the surface of the water, by the weaker van der Waals forces.
1) "Water-coalescence in an oil-in-water emulsion droplet burning under microgravity", Proceedings of the Combustion Institute, Volume 28, Issue 1, 2000, Pages 985-990.
Comment: The "trace of surfactant" gives a bias towards a large interface, favouring the described core-shell structure.
Comment: Absolutely, but I think this is just a matter of how quickly the preferred structure is achieved. Not knowing the concentration of "trace" makes this a bit speculative, but I think it's unlikely that something other than the core-shell structure would form in the absence of the tract of surfactant. I guess it's conceivable that it is holding the 2 phases together, but I suspect that they would be held together by van der Waals (London) forces as proposed in the OP and your answer. By the way, nice catch in your answer bringing up the pressure issue.
Comment: The core-shell structure will be stable if the interfacial tension is less than the surface tension of water minus 0.59 ($=1-2^{2/3}$) times the surface tension of the oily phase (assuming they have the same volume), if my reasoning is correct.
Answer: Your reasoning, that there are still London dispersion forces between the oil and the water, is correct. However the contact area will either be small, because you still have to deform the ideal spherical phase boundaries of each phase, or the phase with higher surface tension will surround itself with the other phase (core-shell droplet, see other answer). It depends on the relative values of the surface/interfacial tensions.
(It does not work in vaccuum, though. The water will boil until it freezes. Just use a big enough container filled with air instead.)
Comment: Wouldn't the air affect the forces holding the two together? That is to say, there would be forces between the liquids and the air that would make it more preferable for them to seperate.
Comment: @Te55eract Not measurably.


File created in Photoshop looks different in Illustrator

Question: I need to design a letterhead and I have this watercolour effect which I created in Photoshop (RGB file). I want to take this to Illustrator and work with this as part of my design for the letterhead. When I place it in Illustrator, the colours seem to vary quite a bit. I suppose this is because its in CMYK and the original is in RGB. Should I be re-working the original watercolour arwork in CMYK in Photoshop? Would the colours match when I take it to Illustrator?
Comment: Yes if ur working in CMYK mode and your file is RGB color do change. Convert them to CMYK
Comment: related: http://graphicdesign.stackexchange.com/questions/28959/illustrator-using-an-rgb-transparency-mask-in-a-cmyk-file
Comment: I re worked the artwork in Photoshop using cmyk, and even then the colours look way off, when i complete it in Illustrator. What should i do to get the actual colours?
Comment: Have you check the profile color in the settings of your document ? in Photoshop and Illustrator.
Comment: what should the profile color ideally be for both Photoshop and Illustrator?
Answer:
Should I be re-working the original watercolour arwork in CMYK in Photoshop?

Not necesary.
Working in CMYK is not that simple, it needs to take into account the profile.
A basic example is the maximum amount of ink. You should not use for example c100m100y100k100.
Most art work, paintings, are better to be done in RGB and then just converted to CMYK. The colors change yes, but you need to live with the change.(*)
An exception is when you have pure colors, for example a watercolour letterhead with only yellow and magenta to produce and combine a yellow-orange-red paint. In a specific case like that yes, you could work directly in CMYK.
(*) But is important to turn the profile on so you can see on screen the aproximate result in CMYK when working in RGB.


Open museum in NYC for Thanksgiving

Question: Are museums going to be open for Thanksgiving? I am also interested about renting a car in NYC, but I cannot find anything open that day. Is the airport the only option?
Comment: there are many museums in NYC, here is a useful site to check their opening times http://www.nycgo.com/schedules-and-admissions
Answer: Based on what I can see from the websites the only museum that doesn't explicitly state that they are closed on Thanksgiving Day is NYC Folk Art Museum though it is quite likely that they are.
As far as car rental is concerned the major car rental companies like Avis, Hertz, Budget have offices open on Thanksgiving in NYC but most of their Manhattan locations (if not all)  report that they don't have any cars for the Thanksgiving day.
You could try ZipCar but you might have the same luck.

Open museum in NYC for Thanksgiving


More General term for "appliance operator"

Question: In the HAM radio community the term "appliance operator" is used to describe people who use radio equipment but don't understand how the equipment works. In IT these people are disparagingly called Lusers.
http://www.eham.net/articles/11116
Is there a term for this in other broader contexts? In engineering what could you call a technical person without the underlying theoretical/technical understanding.
Comment: I don't think there's a common term across all disciplines. Each community has their own slang.
Comment: That (non-)technical person is in Business Development.
Answer: The link you provide contrasts the A.O. with the average "Real Ham". They explain he might be using Ham for work, just as a tool. That's pretty much a user - a person that uses - as opposed to an enthusiast. Whereas Luser is internet slang and derogatory, the A.O. is simply not fascinated by the hobby and is called out for that very purpose.
Answer: '(Equipment) Operator' is the best thing I can think of.


Huawei Ascend P7: "Log In WiFi Network", but WiFi works well, and a very strange issue

Question: I have a problem with my Huawei Ascend P7
The cell phone connects perfectly to WiFi but I have several problems related to this:

Repeatedly asks me to "Log in WiFi network".
Certainly, it connects to the internet, but only for a few moments, the speed
of the connection goes down until it is constantly lost (for long periods of
time).

EDIT: Well, I tried connecting in my cousin's WiFi and worked, now I
  know that the issue happens only in my WiFi

Important data:

This problem does not happen when I connect to a HotSpot, or a public network
(which asks me to login)
My router works perfectly.
Update the ROM (officially) to Lollipop 5.1.1

"Strange" things that happen in this case

The notification of "start session in wifi network" appears for a few seconds, and then disappears.

Once I was able to open the notification, I could even "log in" to my Wi-Fi
       network with Google Sites, but nothing happened

The problem suddenly appeared, I do not know when it happened.

I tried:

Change to static IP.
Check the "Wireless" section of my router
Reset my phone.
Wipe data

I hope to find help to solve this problem, this is the only phone that I will have for a long time (that's why I updated it)
Of course, thank you.
Answer: Check to see if wifi service is actually an app called tispy ..
It hides under the name wifi service


Does placement of ingredients and condiments on a sandwich change the taste?

Question: When making a cold deli meat sandwich or a burger, does layering the solid ingredients and condiments in a different order change the taste or mouth-feel? If so, how and why? Are there reasons to prefer one order to another?
Answer: Yes, it can change the taste quite significantly.
Here's an easy experiment that you can do:

Make a sandwich, but spread mustard on only one of the pieces of bread.
Take a bite of the sandwich, mustard-side up.
Take a bite of the sandwich, mustard-side down.

Mouth feel is affected as well, but not quite as dramatically.
Comment: To add to the discussion of why you would favor one placement over another -- getting things closer to the tongue means you can use less of it; so you can reduce the amount of fat, salt, sugar, or more expensive ingredients but maintain similar flavor with proper placement.
Comment: Great hamburgers often make careful use of mayo-ketchup-tomato layering. There's a magic umami dance that can happen between those slippery layers. Mmm.
Answer: Absolutely! I have had great results with tomatoes directly against the cheese. I can't quite put my finger on why, but no matter where else I've tried putting the tomato slice it just isn't quite as excellent as right up against the cheese (the cheese being right up against the bread in this example (separated only by your favorite choice of lipid =) ))
The timing of its production in relation to its intended time of consumption accentuates the difference that the ordering makes: For example, if keeping a sandwich in a sack for lunch later, I also have had great results putting the lettuce and/or spinach in between solid meat components instead of against the bread, a process which prevents the bread from getting soggy. (Of course segregating the lettuce in a separate plastic bag until lunch time is also an option.)
Aside from my experience, I suppose the fact that I rarely get strange looks from sandwich artists at delis or Subway in regards to any such special requests such as "could you please put the olives under the meat" can be a testament to their understanding that peculiarities such as this are part of the sandwich experience.
Also, if we really zoom in to the elemental level, and observe our food as the combinations of complex chemical compounds that they are, it would stand to reason that the interaction of any given ingredient with any other particular ingredient would vary at least slightly from its interaction with any of the other ingredients, and thus in all likelihood there would at least be some minuscule difference no matter how you changed the layering of your ingredients.
Comment: Good point -- I try to keep the moist things away from softer bread where it might cause it to sog, but I put them close to the bread if it's a firmer bread that might need to be softened up (especially if it's a roll).
Answer: I have always advocated that a, "toasted" Chicken-Cheese-Tomato sandwich is NOT the same as a toasted Chicken-Tomato-Cheese, or toasted Cheese-Chicken-Tomato sandwich. The reason being the heat melts the cheese. In the first one the cheese binds everything together where as with the rest, it stick one ingredient to the bread and the sandwich loses its integrity.
Order of ingredients IS important in a sandwich.
The order of a sandwich helps one to remember how to construct it. It impacts taste and mouthfeel, and it assists with the sandwich structure. It should also be remembered that sandwich ingredient order is also dramatically influenced by culture. For this reason a hamburger in Australia is a completely different beast to a hamburger in the US.
Similarly, butter was always the choice of bread spread (to help protect the bread from soggy ingredients) as I grew up in Australia, after which creamy condiments could then be spread or used as a dressing for salad ingredients.
Oh! ...and using mayo for anything other than binding eggs, or tuna, is down right criminal! :P
Answer: was told once to make burgers starting with the bottom of the bun. sauce, lettuce, tomato, onion, and pickles. then the meat and cheese. was told that is how our taste buds were built and let someone taste all the flavors
Comment: Hmm, so I should turn my Wendy's burger upside down when I eat it.


What are realistic rates for brute force hashing?

Question: I'm trying to gauge password strength assuming that the attacker has a hash of my password. Can anyone cite some realistic contemporary rates at which someone could perform various hashes? I know most sites use unnecessarily weak hashes like MD5 of SHA-1, so rates for these would be the most relevant.
Comment: Keep in mind that if someone *really* wants your password, they can use thousands (tens of thousands? hundreds of thousands?) of nodes to hack it (either by purchasing computer time or enlisting a botnet), so for whatever complexity you think is safe, you ought to multiply it by a million.
Comment: Also, don't forget that most "estimate my password's strength" scripts and guides are quite naive compared to a skilled attacker (who, for instance, knows about keyboard walks and "a"->"@" substitutions and stuff). You can only guarantee the entropy of your password is what it appears to be if you wrote a script to generate it based on /dev/random or something.
Answer: For a simple invocation of MD5 or SHA-1, a realistic rate is between 1 and 10 billions of passwords per second. That's what can be achieved with a good GPU. Furthermore, if the hashing is not salted, then the attacker can share the effort between several attack sessions, usually using precomputed tables (e.g. rainbow tables): an attacker, somewhere, had to hash gazillions of possible passwords once, but then the resulting tables can be applied to thousands of hashes with only a small cost.
If the hash function is proper (as described in this answer), then it uses a slowdown parameter which makes the function as slow as can be wished for. Slowness impacts both the defender (the honest server who uses the hash to authenticate users) and the attacker. We could imagine, for instance, that the defender is ready to invest 10ms worth of his own CPU on each hashing instance, which means that the defender can handle 100 password hashes per second. The attacker can throw more PC at the issue, with multiple cores, and possibly use specialized hardware (GPU, FPGA...), which may give him some boost; let's say that the attacker can be 100 times more efficient at the password hashing than the defender, leading to brute force performance of 10000 guesses per second.
The boost that the attacker can obtain through specialized hardware depends on the function (e.g. a GPU will be good for attacking PBKD2/SHA-256, not as much for attacking bcrypt). How much hardware the attacker will be able to throw at the problem also depends on external parameters (his budget, his motivation...). The slowness used by the defender is a trade-off, because increased slowness uses server resources and may make it more vulnerable to denial-of-service attacks.
Comment: On my dual 6970 setup with oclhashcat: 3B sha, 8B md5, 1.1B sha256
Comment: I'm glad that someone has finally mentioned that expensive hashing generates a DoS vector.
Comment: Thanks for the detailed response. Just for clarity, I'm not implementing a service myself, I'm just trying to gauge how strong my own password is on other people's services, given reasonable assumptions about what they're doing to protect it (i.e., not that much). None the less, your response was very informative, so thanks!
Comment: Use a "good enough" hash, and use both salt and pepper, and more spices if you can - try to not fit into any of the common formats or there will be rainbow tables for them already, and/or programs that already know how to guess them efficiently.
Answer: As of 2020, a 3060 ti video card will, apparently do ~32 billion MD5 hashes per second.  Therefore with a weak password hash (just MD5) a password of 10 random chars from <code>[a-zA-Z0-9 shifted[1-0]]</code> (72 chars)) would yield:
Checking all the possible passwords (3.74E18) hashes would take about 3.7 years on a single nVidia 3060 ti.
<code>@; 72**10/1e18
        3.743906242624487424 (total possible passwords)
@; 72**10/32E9/(3600*24*365)
        ~3.70995275501063013699 (32e9 hashes per second, would take 3.7 years..)
@; log(72**10)/log(2)
        ~61.69925001442312362883 (bits of entropy)
</code>


What does the Bible have to say about dinosaurs?

Question: Archaeology has found many dinosaur fossils.  Does the Bible have anything to say about the existence of dinosaurs?
Comment: You question made me think about it again and I think the question and answer may have been more fully treated here: http://christianity.stackexchange.com/questions/1410/are-dinosaurs-mentioned-in-the-bible
Comment: Archaeology studies past human culture, dinosaurs are studied by paleonthology.
Comment: The solution to the dinosaur dilemma is the concept of megafauna, I believe. Dinosaurs skeletons came from gigantic birds and lizards. Some of them now extinct. The real problem is how and why the mega fauna developed.
Answer: Some commentators (such as the Institute for Creation Research) have suggested that Leviathan (otherwise a Hapax Legomenon) in Job 41 is a dinosaur. Not all agree, but it is at least "out there" as a theory.
Prior to the 1820s, dinosaurs were unknown to (modern) man[1], so it is not surprising the are not mentioned in the Bible. (Indeed, the term would have had no meaning).
If the case is that Leviathan is a dinsoaur, then we read:

1 Can you pull in the leviathan with a fishhook or tie down his tongue with a rope?
2 Can you put a cord through his nose or pierce his jaw with a hook?
3 Will he keep begging you for mercy? Will he speak to you with gentle words?
4 Will he make an agreement with you for you to take him as your slave for life?
5 Can you make a pet of him like a bird or put him on a leash for your girls?
6 Will traders barter for him? Will they divide him up among the merchants?
7 Can you fill his hide with harpoons or his head with fishing spears?
8 If you lay a hand on him, you will remember the struggle and never do it again!
9 Any hope of subduing him is false; the mere sight of him is overpowering.
10 No-one is fierce enough to rouse him. Who then is able to stand against me?

Basically, they are big and strong, but God is bigger.

[1]: To be clear, most scientists believe that man was just a mouse during the age of the dinosaur, and even old earth Creationists suspect that the dinosaurs had died out in the "two days" before man.  During the 1800s, I believe it was Paley who suggested that the dinosaurs must have died out shortly after the flood.  A few die-hard Young Earthers (like the ICR) still advocate that, but for the most part "The Land of the Lost" is just that.
Comment: I used to hear the theory that 'big creatures' like reptiles grow as they age, and if they lived long they would have grown to great sizes.  As men lived very long before the flood, it was argued so did animals, but after the flood, no longer.  Do your know if this theory still floats around and does it jive with the leviathan idea, or was the leviathan intended to be a post flood creature? I have not really researched this one. Just wondering if you have encountered it as the verse you quote is interesting.
Comment: As you never got around to answering, I did some research and it does seem to still be the argument of the creationists. I.e. dinosaurs were like reptiles that really did not last after the flood.  I found an article explaining the creationist view of how the dinosaurs died here http://creation.com/the-extinction-of-the-dinosaurs  Also there are more biblical references about dinosaurs cited at this link. http://christianity.stackexchange.com/questions/1410/are-dinosaurs-mentioned-in-the-bible
Answer: Historians believe that dinosaurs lived before humans. Therefore dinosaurs could be simply mentioned during the 2 days when God created the animals. Gen 1:20-25
God could consider dinosaurs simply animals, and there would be no reason for him to explicitly mention them.
Answer: Technically it is paleontology and not archaeology that is concerned with prehistoric fossils.
There is a (mostly) good book that deals with creation and evolution (among other things) in a complimentary way:  http://www.amazon.com/Science-God-Convergence-Scientific-Biblical/dp/1439129584
There is also the Six Dawns essay which does essentially the same thing from an Orthodox perspective:  http://www.scribd.com/doc/75080212/The-Six-Dawns-by-Dr-Alexander-Kalomiros
Essentially, the focus is on this particular verse:

And God said, "Let the waters swarm with swarms of living creatures,
  and let birds fly above the earth across the expanse of the heavens."
  So God created the great sea creatures and every living creature that
  moves, with which the waters swarm, according to their kinds, and
  every winged bird according to its kind. And God saw that it was good.
  (Genesis 1:20-21 ESV)

We now know from paleontology that some sea creatures evolved into amphibians and reptiles, and some reptiles into dinosaurs, and ultimately some dinosaurs into birds.  So the entire age of the dinosaurs is glossed over in this one verse.  One could argue that since dinosaurs were extinct by the time this passage was written, their inclusion would have been confusing at best to the people of the time.
Comment: Evolution is not a word used in the Hebrew text for the text you referenced, it has the Word: "created"
וַיִּבְרָ֣א (way·yiḇ·rā)
Conjunctive waw | Verb - Qal - Consecutive imperfect - third person masculine singular
Strong's 1254: To create, to cut down, select, feed - There is no room for Evolution in the text of Genesis except in the imagination of man, and the fossil record still shows that today.
Answer: God's Word, although not directly mentioning dinosaurs, does not at all exclude the idea. Here is why:
some scholars, historians, theologians, etc. agree that Adam lived approximately 6000 years ago. Most theologians teach that this is the same age of the universe and earth because Adam was created on the 6th day. But we have fossils of dinosaurs and other prehistoric animals dating millions of years old, obviously contradicting the teaching of 6000 years.
This does not prove that science and God's Word are incompatible. If God is real, then the author of the natural realm is also the author of the Bible. They would have to mesh, fit somehow, as God is incapable of falsehood (Titus 1:2, Hebrews 6:18, Numbers 23:19).
I believe that what I'm about to unfold for you will enlighten your understanding of some time periods in God's Word that, for centuries, have been unclear and grossly misunderstood, misinterpreted, and mistaught, altogether misrepresenting who God is and how beautiful and symmetrical and accurate his Word is.
Consider a section in II Peter 3.

II Peter 3:6: Whereby the world that then was, being overflowed with water, perished:
  This is not speaking of Noah's flood.

This Scripture is speaking of the fall of Lucifer which totally incapacitated Earth and decimated all life forms. The word "perished" (apollumi) means "utterly and finally ruined"
This is something greater than Noah's flood. So from this verse we see a key phrase: "the world that then was" That is a world of an earlier time.

II Peter 3:7 But the heavens and the earth, which are now...

Here is a second set. The word "now" (nun) means "the actually present time;even now; at this instant."
Later in II Peter 3 we see another piece of the puzzle.

II Peter 3:13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.

This is the third heaven and earth mentioned.
We have "the world that then was," "the heavens and earth, which are now," and lastly "new heavens and a new earth." Three in number.
Three heavens and earths- not in space but in time. One after the other. The third will be in the future, as Revelation 21:1 points out.

Revelation 21:1 And I saw a new heaven and a new earth: for the first heaven and the first earn were passed away; and there was no more sea.

The word "first" that occurs here is not necessarily refereeing to the "world that then was" from II Peter 3:6. the word "first" is the word protos which in some cases does mean first, but here the meaning is former, which based on what we saw in II Peter  3 would be referring to the prior set, the second heaven and earth.
Going back to Genesis.
In Genesis 1:28 where the Word is summarizing the formation and fabrication of man, Adam, God's call for them is to "REplenish the earth."
There must have been some form of life that existed and ceased to exist before Adam and Eve and the lifeforms mentions in Genesis 1:20-25,
b. because the scripture says Adam and Eve were to REplenish the earth, to plenish it again.

Genesis 1:1 In the beginning, God created the heaven and the earth.
Genesis 1:2  And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
1st John 1:5  This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all.

Is it logical for a God of light, perfection, order, love, and beauty to work on creating a heavens and earth and the end result is without form, void, and dark?
The creation of Genesis 1:1 was not haphazard, sloppy, formless, dark, crooked, void, empty, etc. It was a perfect, harmonious, light, and beautiful creation.
The Word "was" following the word "earth" in Genesis 1:2 should have really been translated "became."
If we read the transition from Genesis 1:1 to Genesis 1:2 with the added understanding that the word "was" is really the word "became" it fits with what we would expect God to create.
To further substantiate this point, consider the vision of the prophet Isaiah as recorded in:
Isaiah 45:18  For thus saith the LORD that created the heavens; God himself that formed the earth and made it; he hath established it, he created it not in vain, he formed it to be inhabited: I am the LORD; and there is none else.
the word "in vain" from the phrase " he created it not in vain" is the Hebrew word tohu which is the same word as "without form" from Genesis 1:2. Clearly God created the heaven and earth not in vain, he created it with form, he did not create it in the state that it was in in Genesis 1:2, formlessness, it became that way.
So just to frame this out even clearer: Genesis 1:1 is literally on its own compared to the rest of the chapter. Genesis 1:1 is the first heaven and earth, while Genesis 1:2 and onward is the second heaven and earth. the second heaven and earth is obviously the same rock, the same elements, from the first heaven and earth, just refashioned. If this were not the case we would not have the fossils and prehistoric evidence that have been discovered over the face of the earth.
So Genesis 1:3-2:4 is just a reframing,reorganizing, replenishing of what once was from the original of Genesis 1:1.
Between Genesis 1:1 and Genesis 1:2 was eons of time. As far as we understand it was basically however much time is between the creation of matter, I know the scientific realm has approximate ages for this point, and the creation of Adam. So dinosaurs, cavemen, cave paintings, mammoths, all those things would have to fit within that expansive timezone unspoken of between Genesis 1:1 and Genesis 1:2. We know time went by between those two verses even though nothing is specified. We know there was a war in heaven, and Lucifer fell;

Revelation 12:3 and 4  And there appeared another wonder in heaven; and behold a great red dragon, having seven heads and ten horns, and seven crowns upon his heads. And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born.

and his fall racked and ruined that life on earth. Then God turns the lights back on and rebuilds, re-initiates his creation, with one difference, and enemy of God in the world, Satan. Then the Story unfolds from Genesis 1 and 2 and mankind then needs a redeemer, and Christ was that for us.
After the return, and reign of Christ, the third heaven and earth begins, which is the true restoration of "the world that then was" Paradise will be restored, and this time, with no adversary, no death, no crying, no fear. That is our hope.
Comment: The problem with the gap theory is that if the earth became formless after the billions of years then there wouldn't be any fossils to find. And it still has death before the fall. But this is a decent explanation of the gap theory.
Comment: 2 Peter 2:5 would be in the prior chapter context to identify that the flood was in fact Noah's flood @user13742 - To Argue that it was anything but Noah's flood and still based on scripture, one would have to find such an OT story, which Peter is replete with OT examples, so to assume that 2 Peter 3:6 isn't Noah's flood is an "argument from silence".


How to know if an existing set of automated tests are effective?

Question: I came to a new project and it was already written 100 autotests. The product is new. How to determine whether the tests are effective? What is the best way?
Comment: Deliberately introduce bugs in the code, and see if they are caught? Either ones of your own devising or ones purportedly fixed.
Answer: Learn how to use the product as an end user.  Become familiar with all the functions, error pages and workflows.
Then study the tests.  Observe them run and/or look at their code and ask yourself:

Is there functionality in the UI that you do not see UI tests for ?
Are there automated UI tests for things you cannot do in the UI ?
Do feature tests cover happy, sad and optional workflows ?
Do unit and integration tests exist for the backend functions that support the ui ?
Is security tested?
Answer:
Determine coverage (of source code) and add test exercising parts not covered yet
Found most often used "paths" through the system, and different kinds of users would use it. Check if most common are covered.

"Best" way depends what you want to cover. What is critical. What business sees as most important. There are many ways to measure it.
Answer:
How to determine whether the tests are effective? What is the best way?

It is a new product, so there is little historical test results to compare against, but can you

Find a similar product, how is this similar product tested? Can this similar product be tested effectively? How are your test cases compared to those for the similar product?
Over time, there will be bugs. Can your test cases catch those bugs or not? If an easy to catch bug manages to slip into production, that means your test cases need improvement.
The best way to define "effectiveness" for a given product is to measure against its own historical product quality.
Answer: The version control systems for both the tests and for the product code should be able to quickly answer the following questions:

Were there any changes to the code due to the tests finding issues?
Were there issues found that were not found by the tests?
Were tests introduced for such issues and when run on code from before the fix would they fail?
Are there tests that currently fail?

You can also look at test coverage of the code & specification, traceability between specification and tests will give a good indication of this.
Answer:
How to know if an existing set of automated tests are effective?

Effective tests can be hard to gauge. The problem with automated tests is that they find less bugs over time.
Having said that, I find the regression testing mnemonic RCRCRC proposed by Karen Johnson useful when evaluating existing tests. Although specifically designed for regression testing I still think they work well.

Recent. How recent are the tests? Do they cover new features, areas or changes? Or are they primarily old tests?
Core. What functionality do these tests cover? Are they the critical or essential functionality?
Risky. What features are riskier than others? What features are more likely to be broken?
Configuration Sensitive. What code is dependent on environment settings? How might this change based on different environments (Staging, Production, etc)?
Repaired. What features or code has been fixed or repaired recently and might still have more bugs around it?
Chronic. Features or code that always seem to be breaking or having issues.
Answer: Now a days computers are fast enough to automate mutation testing.
You run all the tests, make sure they are green/successful. Then introduce a mutation and run all the tests again and expect it to be red/failing.
Any mutation that is not caught by a test, means you lack a test.

Mutation testing is based on two hypotheses. The first is the
  competent programmer hypothesis. This hypothesis states that most
  software faults introduced by experienced programmers are due to small
  syntactic errors. The second hypothesis is called the coupling effect.
  The coupling effect asserts that simple faults can cascade or couple
  to form other emergent faults.

General code coverage could also help, combining both coverage and mutation testing will go a long way to proof that your test suite is effective in catching unintended changes or small defects.


Is there a way to get international protection on a provisional patent?

Question: Is there a way to get international protection when registering for a provisional patent?
Answer: There is no such thing as international protection in the sense of world-wide protection. Each country issues its own patents based on its own patent laws and its patents are enforceable only in its courts. There are regional bodies like the EPO for Europe that offer the possibility to go through a single examination and end up with patents issued by several countries. And there are many international treaties that are helpful to someone who wants protection in more than a single country.
The closest thing to international protection is a PCT (Patent Cooperation Treaty) application. Filing a PCT application gives someone the ability to eventually file that application's content in over 140 countries. Each location will later need to be separately addressed (money and an examination procedure) to get any rights. PCT applications can get priority from a provisional application if the PCT application is filed with one year of the provisional application's filing.
Comment: Thanks for the response George! much appreciated i'll consider it definitely.
Answer: I think this is what you are after:
Can a U.S. provisional patent application be used for foreign priority purposes?
Yes. A U.S. provisional patent application is recognized internationally in all major countries (e.g. Australia, Singapore, Japan, UK, China and New Zealand). Please keep in mind that a non-provisional foreign application must be filed within 12-months of the provisional application's filing date to retain the earlier priority filing date. The World Intellectual Property Organization (WIPO) recognizes provisional patent applications for the purposes of priority also.
http://www.patentwizard.com/faq.aspx
Comment: A U.S. provisional application establishes a priority date (for a year) exactly the same as a U.S. non-provisonal would. All 140+ countries of the WTO and even more under the Paris Convention would follow this. A U.S. non-provisonal within a year is *not* required. You could file a UK application within the year, get priority from the U.S. provisional and never file a non-provisonal in the U.S., for example.


D7 - Rules System Page Redirect not working at all?

Question: I've been trying to add action Page Redirect to my rule (after a coupon code is applied to an order), and it doesn't work in any scenario? I did a bit of digging and it seems this is common - anyone know why it's happening/what the fix is?
Answer: First things first: a page redirect from "current page" to "current page" is what seems to be your very last Rules Action, is that what you actually want? If that's not your issue, then read on about a possible approach to find out what else might be wrong.
Basic debugging
Rules is great, but sometimes also tough to debug if things don't work as you'd expect. There are some typical facilities to do such debugging, but my Keep-It-Super-Simple technique I often use is my BINGO-trick. A sample of such rule can be found in my answer to "Which Rules condition can be used to email a user when an admin updates their profile?". Stupid, but simple and efficient (I think).
Also, since you have 2 Rules Conditions in a single rule (both must be satisfied for your Rules Actions to execute), you should try to see what happens (if you get a "bingo") for each of the individual Rules Conditions. This by simply (temporary) removing 1 out of the 2 Rules Conditions you are using, and verify if they each result in the Rules Action you'd expect (also just a simple Bingo-message should be sufficient).
Advanced debugging
Something else that will help you find the answer to your question, is to have a look at Rules debugging ... Within the Rules settings, experiment a bit with the debugging facilities that come with the rules module. At least have a look at the "Rules Evaluation Log" (to check that the Rules logic being executed, actually matches what you expect that logic to be).
Depending on what the result of that type of debugging is, you may also want to (temporary) enable the Devel module, so that you can (temporary) add a Rules Action like "Display a value" (in your case of your node:comments).
For way more details about these 2 variations, refer to Rules debugging, as explained in the answer to "How can I display the value of a variable inside a condition?".
Comment: Re your first sentence - from current page to current page is correct; I simply want the page to refresh after a coupon is added. Will dive into the above suggestions shortly :)


I forgot my Encrypt Local Backup password. How can I start over?

Question: In iTunes (Windows 7) Encrypt local backup is checked, and I can't remember the password. I don't need to restore my iPad; I just want to be able to back it up. If I attempt to uncheck this, iTunes prompts for my password. How can I start clean (without losing any data from my iPad, which has not been upgraded to iOS 6)?
Comment: See https://apple.stackexchange.com/a/306826/10713
Answer: From Apple Support:
Warning: If you encrypt an iPhone backup in iTunes and then forget your password, you will not be able to restore from backup and your data will be unrecoverable. If you forget the password, you can continue to back up and use the device, however you will not be able to restore the encrypted backup to any device without the password. You do not need to enter the password for your backup each time you back up or sync.
If you cannot remember the password and want to start again, you must perform a full software restore and when iTunes prompts you to select the backup from which to restore, choose set up as a new device.
I assume it applies also to iPad, and yeah that's a terrible inconvenience for you, but at least it's a definitive answer from the source.
http://support.apple.com/kb/HT4946?viewlocale=en_US&locale=en_US
Comment: One note: I encrypted my backup on my iMac then had to back my phone up to my MacBook Pro. iTunes on MacBook Pro asked for an encryption password. This had me confused because I had never backed up to the laptop before. After a while, I realized that it was using the same encryption password from my iMac. Ergo: the encryption password is shared amongst your OS X devices.
Answer:
Open iTunes preferences from the Edit Menu.
Click the Devices tab. Here you will find the backup for your iPad.
Delete it by clicking the Delete Backup button below the pane.
Now you can start over.
Comment: I don't have enough rep to vote this down, but it is not correct. I just followed the instructions, and the "Encrypt local backup" option is still checked and cannot be unchecked without the password.
Comment: This does NOT work, just tried it (iTunes v12.3) - the backup is deleted but the Encrypt option is still greyed out and I can only "change password" - which I cannot do since the old one is unknown. Another bad iTunes feature
Comment: That's not possible. Try restarting iTunes.
Comment: I just tried it with my iPod touch, and it works.
Comment: Restarted iTunes (latest version). Same issue. This is with an iPad (although I wouldn't think that would make a difference).
Comment: It is very unlikely, but probably this is because the iPad and iPhone are cellular? I can't help you after this, as I can't recreate your problem on my Mac. Sorry.
Comment: I'm guessing that this is because the setting is stored on the device in the `/private/var/Keychains/Keychain-2.db` file mentioned [here](http://www.iphonefaq.org/archives/972853). As far as I can tell, you have to be jailbroken to access it though.


How can I get stains out of a pine table?

Question: I have a light pine dining table. After we got married, we left an orchid from the wedding on the table while we went on honeymoon, giving it a bit of water before we went. Didn't realise the pot wasn't water-tight! The water leaked out onto the table and has created quite widespread water damage which obviously wasn't dealt with early.... Can anyone suggest how to get it back to a lovely even finish? Haven't tried any stains yet as wanted to get advice before I tried anything.
Answer: Some background, there are two types of wood water stains. White rings and black marks. White rings form when the water has only made it into the finish, this is the "best" kind of stain to have. Black marks occur when the water has penetrated into the wood itself. This is slightly harder to fix and will ultimately require either sanding or covering it with a richer, darker stain, although sanding is the only sure-fire method.
There are some options that involve staining or not, I'll start with the least invasive.
White ring removal

Place a dry, clean white lint free shirt or bed sheet over the water stain and rub with an iron at medium setting for a few seconds, then lift the cloth and repeat until the stain is gone. You want to be rather brief in the application of the iron as not to further damage the table. You can use a hair drier too. This works very well on antiques with delicate finishes that you can't replace.
Apply lemon oil to fine steel wool, make sure it's fine, and gently buff the rings out.

Black mark removal

Stain the wood with a suitable, darker stain. This is a judgement call, if the black mark is very pronounced or covers a large area you are better off sanding. You can test this out because if this doesn't work, you are sanding anyway.
Sand the table down to the wood and begin bleaching. Use a brush and apply bleach to the black marks as best you can, let it sit for a few hours and reapply until the stain is gone. If normal bleach doesn't work get some commercial wood bleach. Follow the instructions but you should have two bottles as part of a kit. After application it should start bubbling. Before finishing and project and restaining, you MUST apply a mixture of 2 parts water and 1 part vinegar to the area you bleached to neutralize the bleach, then rinse with normal H20. This is to ensure a good surface to re-stain.
Answer: The secret to removing a fresh water stain is to use alcohol. Alcohol will attract water, bind to it, then evaporate. Use the purest ethanol you can find.
I will tell you a funny story. A refinisher is called to a house to remove a water ring and there are two cherry end tables, one of which has the ring. The guy tells the lady it will take an hour or two, so she goes off somewhere. The refinisher then removes the ring using alcohol which takes him about 5 minutes. While he and his assistant are sitting there relaxing, he says to his ward, "I will teach you something about human nature." They then switch the two end tables which are identical. The lady comes back and examines his work (even though she is looking at the wrong end table). She says, "I can still see a little bit of the ring, but most of it seems to be gone, thanks very much." The apprentice refinisher learned something important that day.
Comment: I know! I know! The apprentice learned he could charge 2h of work for something that takes 5min, right!?!


2012 Ford Escape negative cable removal

Question: On the 2012 Ford Escape the negative battery cable clamp is very different from the positive cable clamp. The negative has an upright bolt and nut that compresses a set of  split bars when you tighten the nut. I have removed the nut but cannot remove the bolt as it has to be removed downward and the battery is in the way. The clamp is still blocked by the split bars and will not allow the clamp to be lifted and removed. So i ask, how do you remove the negative clamp from the post?
Comment: It would be great if you could add a photo of the negative battery post.
Comment: Update: I went to Ford and they could not get the clamp off either. They said I was faced with 2 choices: Replace it ($110) or replace teh clamp only ($70). I said no to both. The car is running so I went home, sent an email to Ford Corporate Cust Svc and complained about the design problem and why should I pay that kind of money for this poor design. They say they will get back to me. We'll see.
Answer: If this is what your battery clamp looks like:

Take the nut off from (in the image) right side. Then take the small piece under the nut off. The bar which goes through there should now be loose. Take a screwdriver an place between the two sides of the clamp just outside of the battery post, then twist the screwdriver to loosen the clamp up. You should now be able to remove the clamp by moving it back and forth and pulling it up. You don't have to remove the small bolt to get the clamp to release.
Answer: If the bolt looks something like these photos:

Then all you probably need to do is to tap gently on the top of the bolt (leave the nut on, but loosened, to protect the threads). A tap or two should be all that you need to get the bolt to drop down a bit and release the terminal clamp.
Answer: I just went thru that exercise. It turned out that the clamp had worn a groove in the battery terminal. You couldn't easily remove the clamp even though it was obviously loose. I finally inserted a tool underneath and pryed the clamp up and off. It took a surprising large amount of force for a little groove barely a 1/2 mm deep.
Comment: Did you try spreading the clamp, like @Paulster2 suggested? That will often help. When prying up, I'm always concerned about damaging the case of the battery. I'll sometimes use a wide putty knife or something similar to spread the load. Also, it helps to keep the clamp level as it comes up, otherwise it can cock and dig in.
Comment: In my case the battery was totally dead, tested and verified.  We were replacing the battery and we knew it.  The clamp was QUITE loose, and still wouldn't come up.  It was one of those stamped metal clamps and not the cast solid type.  It was surprising how wide we opened the clamp and it STILL WOULD NOT COME OFF THE BATTERY.    It was a surprise that there was even a groove there.  So no, we did not try to spread the clamp any more because if we did that, we would have bent it beyond use or snapped it in two.  Why, do you think I offered this as a separate answer? Its a different root cause!

2012 Ford Escape negative cable removal


Can I replace an old closet light with multiple electrical outlets?

Question: I have asked a family member to replace an old light fixture in a large walk in closet with an actual electrical strip. The house is an 101 year old craftsman. There aren't any electrical outlets in that corner of the small house. The closet(has windows so it will be my office) I will need electricity for  desktop pc, printer, at least one light, and just outside the closet I need to run at least two more lamps. Is that safe? Is it too much? We won't be doing iside wiring. Again only an old light fixture that has electrity running though an old fashion "flex tube" for lack of a better word.It is on the outside of the wall. ANY precautions or ideas?
Comment: This refers to a circuit breaker or fuse. They are located in the electrical panel near where the wiring comes into the house, often in the basement (or sometimes the kitchen or hallway). The size refers to amperage on a particular line and is expressed in numbers, such as 15A or 20A. The line in question is the one that serves the old light fixture. Finally, your level of familiarity suggests that you probably should have a professional or at least a very knowledgeable friend manage the project.
Comment: You're going to have to provide more information.  What size overcurrent device is protecting the circuit? What other loads are on the circuit?
Comment: Another issue to look into besides circuit size and connected load is equipment grounding. Unless the electrical has been redone, I suspect a house this old has no grounding conductors. Not only is this important for personal safety, but desktop PCs need to be properly grounded, as do any UPS equipment or surge protectors.
Comment: I don't know much about it? Where do I look to find out??
Answer: The best answer to this is to leave the light as a light and have a qualified electrician run a three wire circuit (hot, neutral, ground) direct to your soon-to-be office. Your modern equipment needs it and disturbing any old turn of the century wiring is asking for disaster.
Having lived in an old house with Range, Pump and four circuits, adding any extra load to an ancient system without upgrading the wiring is a good indicator for having several fire detectors located in strategic places and keeping their batteries up to date.
Answer: Here is the problem (and its one I've run into in my own home):  Those old houses were usually wired with just one or two circuits of knob and tube wiring.  Then, over the years, people add to those circuits (usually overloading them) or add new circuits.  Sometimes they even splice newer wire into the old stuff, so you think you're working with a new circuit when it really connects to old, crumbling, overloaded knob and tube wiring in a wall somewhere.  If you can determine that your light is connected to any old knob and tube wiring (black, dirty-looking, crumbly insulation on the wires), then that is an automatic disqualification for adding anything else to the circuit.  In fact, that wire should be replaced throughout the house as soon as possible.  If your circuit uses newer, plastic coated wire (one black, one white, one bare copper) and you are SURE that new wire goes all the way back to the breaker box with no connections to old wire, then you can analyze your circuit to determine whether you can add more to it.  Here's how:
First, go to your breaker box and turn off the breaker that controls that light.  Note the number on the the switch.  It's probably a 15 or a 20.  This tells you how many amps the breaker is designed to let through to your circuit.  Now, go through your house and figure out what stopped working (other than the one light in question) when you turned it off.  Be sure to check outlets, lights, porch lights, appliances, etc.  How much stuff quit working?  If it was just a couple of lights, you're ok to add on to it.  If it was a bunch of lights and outlets, then you're not.  As a basic rule of thumb (for a DIY project, not a professional electrician) multiply the number on your breaker by 100, so it will be either 1500 or 2000.  For every light bulb that quits working when you turn off the breaker, subtract 100 from that number.  For the first outlet that quits working, subtract 1200 from the number (That's for the possibility of a vacuum cleaner getting plugged in to one outlet on the circuit).  For additional outlets, look at what is plugged into them.  Are they high power items, or just cell phone chargers, clock radios, and stuff like that?  If it's just little stuff like that, subtract 50 for those outlets (in addition to the 1200 from the first outlet).  Count lamps the same as a light bulb.
If a bathroom outlet stops working, don't add anything else to the circuit.
If a kitchen outlet stops working, don't add anything else to the circuit.
If any appliance, such as a washing machine, microwave, or space heater, stops working, don't add to the circuit.
For anything that takes more power than a light bulb or a cell phone charger, you have to figure out how many amps it draws (usually printed near the cord somewhere), take the amps times 100, and subtract that number from the 1500 or 2000 you got from your breaker.  If the item tells you how many watts it draws, then divide the watts by 120 and multiply by 100 and subtract THAT answer from the total.  Next, subtract 100 for each new light you want to install. Then subtract for the power your computer will use.  Most computers have at least a 400 watt power supply, plus printers etc. You'll need to check yours for the exact number. If, after all of that subtraction, you end up with 100 or less, then don't add to the circuit.
If your circuit breaker is a 15, DON'T change it to a 20 to get more power!  It doesn't work that way.  If it's a 20, be sure to use 12 gauge wire for your expansion.  If it's a 15, use 14 gauge wire.
Comment: Many of your suggestions make sense, but this questioner is so inexperienced that any handling of wiring or fixtures is very risky. Even a look inside the panel box requires removal of the cover. Sharon needs a pro. A DIY project needs either a low risk task or at least some familiarity with the field. As is said in the medical field, when picking up a scalpel, you need to at least watch one before you do one.


Greyhound bus ticket (print at home)

Question: Really silly question but just to make sure: do I just print my Greyhound bus ticket out and I'm all set for my ticket, or do I need to cut it out? I'm only bringing one bag, could I bring that on the bus?
Answer: If it's a suitcase, they may ask to check in (which goes in the check in bin in the belly of the bus). If it's a back pack or something similar, you can carry it with you. As far as the ticket goes, you can print it from your home, print it out from a kiosk at the bus stand or use your smartphone to scan the e ticket and avoid any printing altogether.
Comment: You can't print Greyhound "print at home" tickets at station kiosks or counters. If you want to do this you need to select "will call."

Greyhound bus ticket (print at home)


How to draw line plot with multiple lines on Tableau?

Question:
I have 4 different measures which I want all on the SAME line plot. They do have the same scale. I tried dual axis but it doesn't work for more than 2 plots.
Answer: Use "Measure Values" in your Measures Tab. Pull it in Row, and then under the Measures Marks, pull in all the measures you want to display.