UI for multi-select batch editing where eligible item list changes depending on the action

Question: We have a list of items in rows with the first column being a checkbox so you can select it. Additionally, above this grid list of items are several search criteria to narrow down the list i.e. think of the Gmail inbox with emails and the first column is a checkbox and several search type boxes above it to search on specific attributes of the items.
Search By
Filter 1: _____________   Filter 2: _________________
Filter 3: _____________   Filter 4: _________________
Results
[ ] | Item 1 | attribute 1 | attribute 2
[ ] | Item 2 | attribute 1 | attribute 2
[ ] | Item 3 | attribute 1 | attribute 2
The problem is, not every item in the list can have every batch edit action taken upon it. As an example, let's say you search Gmail for a certain subject. The result has emails that are in Trash and your Inbox. If you want to move some of the results to Trash, we don't want the current ones in trash to be selectable.
So we need a way to first let the user tell us what type of action they want to do, then hide checkboxes on the rows where they shouldn't be allowed to do that, then they can check what they want, and finally confirm to perform that action on the selected items.
Idea 1:
We thought about having a button like "Select Items to Move to Trash", which then displays a modal popup that would show only those items that are eligible to move to trash. But they will likely want to do additional filtering by default, and there is already a sophisticated way to filter the items on the current page that we don't want to replicate on the modal. Plus, there is already a sophisticated way to determine which columns they see, which show additional attributes about each item in the list that they may need to make the determination of which items to select. And again, this feature is already on the main page and hence don't want to replicate it.
Idea 2
Add new filters up top to restrict the results below based on the Bulk Action they want to take. i.e. Items Eligible to:  Move to Trash or Move to Archive, etc (which are radio buttons). They can select other data limiting filters too, then click Search to bring back the results. In this case, every row would be eligible since we had the highest level filter being that to restrict the results that are eligible for that batch action. If they don't select any of these "Action Filters", we don't display the checkbox column.
Search By
Items Eligible To: [o] Move to Trash [o] Move to Archive
Filter 1: _____________   Filter 2: _________________
Filter 3: _____________   Filter 4: _________________
Results
[ ] | Item 1 | attribute 1 | attribute 2
[ ] | Item 2 | attribute 1 | attribute 2
[ ] | Item 3 | attribute 1 | attribute 2
Answer: There are two typical ways of user behavior:

I need to do some action (move to trash) so let me create list by searching and then mark appropriate items.
I created list by searching, now I mark appropriate items and then select some action to do (move to trash).

We can support both behaviors using the following:

Add filter option as 'Filter by Action'. This supports the first behavior.
Just do action on records which support it and then update list after the action. Some items will remain selected and you should warn user about that they don't support the action.


Once a cheater, always a cheater

Question: I wonder if the title phrase is ever used in a meaning different from the obvious one: cheating in a relationship? Can it refer to cheating in an exam or obtaining money in a dishonest way?
Comment: The phrase can refer to all sorts of *cheating*. Not all people remain a cheater, though.
Answer: The "Once a, always a" is a common saying and can be used to illustrate multiple situations:

once a ——, always a ——
proverb: A person cannot change their fundamental nature
  once a whinger, always a whinger

(Oxford Dictionary)
So yes, you can use it for other types of cheating as well.
Comment: Thank you, that helped :) When I googled the phrase, the first 30 hits referred to cheating in a relationship ...

Once a cheater, always a cheater


"Launch Configuration" Shows up Blank When Trying to Export Runnable Jar?

Question: I've gotten this to work in the past, but now whenever I choose File > Export... > Runnable JAR File and select the drop-down menu "Launch Configuration", all I get is a blank bar.
How can I get my main class to show up?
Answer: Launch configurations are presumably used because they describe the main class you want to run, and the libraries the main class needs.  They are created automatically when you run your main class inside Eclipse.
In the Package Explorer panel, right-click on the class you want to have main(...) executed in and choose Run as -> Java Application to run your program.
This process creates a launch configuration you can use (and save too, if you make it shared)
Comment: Worked nicely. I was trying `Run > Run` From the top menu until I re-read what you wrote and right-clicked the main class after pressing the `+` in the left sidebar to open it up.
Answer: I came across this same issue today as I have many times in the past, and although I've usually corrected it as Thorbjorn has posted, for some reason it was not working for me today.
Typically I would just browse to the project, search for the main class, and hit apply then run, but it wasn't working.  Still wouldn't show main class while trying to export runnable jar.
I actually had to go run configurations, and right click on the window to the left under Java Application and click 'new'.  It then created a new configuration item where I could browse to the project, and add the main class.  Then it would show up while trying to export runnable jar.
Answer: This "launch configuration" thingie is all fine and good, but you probably just want to specify a main class. One of the pages of the "export" dialog will let you browse for and specify that main class, without the need to go looking for an appropriate configuration. That's how I do it.

EDIT
What I do is
File | Export | Java | Jar File
Then I select the stuff I want exported.
Next | Next and I get a chance to specify my main file.
Comment: I don't see anything to specify the main class. The first page gives me the option of what I want to export, then the second page has the options: `Launch Configuration`, `Export Destination`, `Library Handling`(radio buttons), and `Save as ANT Script` (checkbox).
Comment: The launch configuration is needed to give the class path.


What DAL level is IFE software certified at?

Question: An inflight entertainment (IFE) system has software for the computers and for the seatback displays. What DAL level is the software classified at?
Comment: Welcome to aviation.stackexchange! You are asking many questions at a time. Could you please rephrase your question to only ask for one thing. You can then create more follow up questions and link them to this one.
Comment: Done. Thank you.
Answer: DAL is specific to a design and installation. It's a flow down from the aircraft system requirements and design and the safety assessment process.
These processes are defined in SAE ARP4754A Guidelines for Development of Civil Aircraft and Systems and ARP4761 Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment.
ARP4754A is the more relevant to this question. A summary of the process is to start with a Functional Hazard Assessment which identifies hazards associated with failure modes of specific functions. Based on the severity of the failure condition a Functional DAL (FDAL) assignment is made.
The next step is to assess the architecture for functional and item independence. This allows for setting Item FDAL for each of the components of the system.
It can get complicated, but for a simple example: If you have an FDAL B and FDAL E function combined into a single item with no independence, the IDAL of both becomes Level B. If they are functionally independent and also independent items, the IDAL would match the FDAL for each.
Back to the question: An old colleague of mine worked much of the certification effort for the B777 IFE when he was at Boeing. As he explained, the highest criticality function in the IFE is the PA override function which is FDAL C. The rest of the IFE system was set at Level D. (you could argue for Level E based on the argument that losing it has no safety effect, but the Level D is based on the requirement that you show non-interference with any other system.)
The question as posed, is about the software which means we're asking about IDAL. If the IFE SW architecture is a single application or multiple applications that lack independence from the PA override code, the IDAL for the IFE SW will be Level C.
It may be possible to architect the SW with proper hardware or software partitioning to provide independence of the functions and items. In that case, the independent items could be developed at the lower IDAL level.
Answer: While I haven't worked directly with IFE software, I would expect it to be either DAL D or E, depending on the integration with the rest of the cabin systems.
Most likely it would be DAL E, as the failure of the IFE system should have no bearing on the safety of the flight systems themselves.
Comment: ...unless you're on Swissair 111, but that wasn't software (I think).
Comment: From the reports, Swissair 111 was likely cause by the IFE wiring, definitely not the software.
Answer: I can answer with certainty on several products I am familiar with that they are certified to DAL C.  This seems a bit much in my personal opinion, but it is a fact.
Comment: Is that DAL then driven by the specific OEM/installer? I don't recall a TSO geared towards IFE systems to help guide their criticality level, which leaves either PMA or TC/STC.
Comment: I am not certain what drives this, it is a different division that handles these particular products.  And for clarification, the hardware is various power supplies for the IFE systems, and not the displays themselves.
Comment: Please note that we are talking ONLY about IFE software and not the IFE system. I am having a hard time visualizing why it would be at DAL C - there is nothing in there to be at a failure condition of "major"


Identify transactions issued by the coordinator

Question: I am listening for new transactions on the ZMQ stream published by the iri. Is there a way to identify transactions that were created by the coordinator?
Answer: If you query a node with the getNodeInfo command, it will return a JSON object similar to the following:
{
    "appName": "IRI",
    "appVersion": "22.214.171.124",
    "duration": 0,
    "jreAvailableProcessors": 8,
    "jreFreeMemory": 1824745296,
    "jreMaxMemory": 3987734528,
    "jreTotalMemory": 3987734528,
    "jreVersion": "1.8.0_112",
    "latestMilestone": "FRAYIUUSUGMTASGCPQJUZHVCZGAPESWFMZBWWSNSHJZXFCFBV9X9CVQZHVTQSLXJBDUGVWRDFUVO99999",
    "latestMilestoneIndex": 292862,
    "latestSolidSubtangleMilestone": "QGCJGNDLGERQRHRDGYJJYIYBDZVGTLNIGGFKLSPQMCPMRUEJQDFKDLAJKLWYEODLKYXCBVJCKDY9A9999",
    "latestSolidSubtangleMilestoneIndex": 292053,
    "neighbors": 21,
    "packetsQueueSize": 0,
    "time": 1512056790045,
    "tips": 5005,
    "transactionsToRequest": 0
}

The latestMilestone value is the latest co-ordinator transaction hash as seen by the node. Continuously monitoring this on your own node would be a way to record all the co-ordinator txs.
Comment: There is no guarantee that your node will see all milestones before the next milestone arrives, but to get the latest milestone (or if you do not care if you miss some), this is fine.
Answer: All transactions from the coordinator (on mainnet) will send 0 IOTA to/from address KPWCHICGJZXKE9GSUDXZYUAPLHAKAHYHDXNPHENTERYMMBQOPSQIDENXKLKCEYCPVTZQLEEJVYJZV9BWU, and their tag will be the milestone number.
Note, however, that anyone can send such transactions, so there might be more transactions like this that are not coming from the coordinator. To be sure, you'd have to verify the signature of the transaction, or check whether a node trusted by you picks the transaction up as latestMilestone
Comment: no problem. It confused me first, too. On the other hand, tangle can be quickly searched for address/tag combo, so if you want the hash of a previous milestone, querying it is fast (and you have to verify the signature afterwards anyway if there is more than one result).
Comment: @Zauz: Why did you edit my post? The "message" contains the signature, while the tag (or obsoleteTag depending on how you call it) contains the milestone number.
Comment: tbh I just assumed... now I know better. sorry. Thanks for being observant and point it out


How is it possible to calculate potential energy?

Question: I'm working through an 11th grade physics course and am trying to grasp the concept of kinetic potential energy. According to an equation I'm given, potential energy can be expressed as $$m * h * g.$$ Thus, as an object falls, it's potential energy decreases, converting into kinetic energy. Now according to this equation, if an object (like a ball) is at the edge of a cliff, it has lots of potential energy. However, if that same ball is at ground level, it's potential energy is zero.
But really, isn't gravity pulling on both objects with virtually the same strength? And aren't they both sitting on a solid surface? Thus, the tension, or "stored energy" in each object should be the same, right?
Answer: Welcome to physics stack exchange !
Actually there a couple of concepts which have to be cleared up for answering your question: Essentially,  kinetic energy and potential energy: First of all: a body, a ball, for instance, only has kinetic energy when it moves. So the ball at the edge of the cliff does not have kinetic energy, not yet, only when it starts falling, then it gets kinetic energy. On the other hand, it has at the edge of the cliff "potential energy", this is what  in simple words saying is "stored energy", energy is can be potentially be converted into kinetic energy.
So the formula you cite:   $m\cdot g\cdot h$ is  actually the potential energy : $E_{pot}=m\cdot g\cdot h$, it turns into kinetic energy if the ball starts falling from the cliff if the cliff is of height $h$ with respect to the ground at the foot of the cliff.
A very important thing to know is that the observer has to fix a reference level for the potential energy, that means the level where the potential energy is supposed to be zero. In the experiment you propose the reasonable level for this is  the ground at the foot of the cliff.  This makes sense, because the ball on the ground is  at height zero, so the potential energy $E_{pot}=m\cdot g\cdot h =0$. Actually, the choice of the reference where to define zero potential energy is free. One could  choose another level for defining  zero potential energy, but it would unnecessarily complicate the reasoning if we chose another reference level in the "ball at the cliff experiment".
Finally I come to your last point: You are right: All objects fall with the same strength, or to be more clear: All object fall with the same acceleration: On earth, the acceleration of gravity is called $g$ and you use it the cited formula. This fact can be used to compute the speed the ball achieves when it reaches the ground. When this happens, all potential energy has been converted into kinetic energy $E_{kin}$ and we can set up the following equation:
$E_{kin}=E_{pot}=mgh$
And finally knowing that kinetic energy can be computed from the velocity and the inertial mass of the object: $E_{kin}=\frac{1}{2}mv^2$, we can say:
$\frac{1}{2}mv^2=E_{kin}= E_{pot}=mgh$
And now we see that on both sides of the equation we can cancel out the mass $m$:
$\frac{1}{2}v^2=gh$
and we can compute the velocity of the ball when it reaches the ground:   $v = \sqrt{2gh}$. This velocity is independent of the mass!  Amazing, isn't it ?
Actually, this already a lot of explanation, may be even far  too much, so if you don't understand it, send a comment.  Then I'll try to explain more. Nevertheless I hope it helps you understand the concepts of kinetic and potential energy better.
Comment: Thanks for the answer! I actually have no problem using the equations, and I'm pretty sure I'll ace this test, it's just the actual _concept_ of potential energy that's bothering me. I suppose my real question is: is potential energy just a theoretical expression, or is there really some sort of "energy" stored in an object on a cliff as opposed to an object on the ground?
Comment: When we say potential energy is stored in the object, one has always to keep in mind that this type of energy depends on the reference point. What counts is the potential energy difference between the object at the edge of the cliff and the object on the ground.  This concept is also the basis of the energy conversation. Actually, you can store energy by putting a massive object on a cliff and release it when necessary(well better not a bit dangerous) the same as using some chemical compound like fuel that stores (this time chemical) energy which can be burnt for driving a motor when needed.
Comment: @CalebBertrand: I've removed the phrase about the gravitational mass. After thinking about it  I realized that in both types of energy $E_{kin}$ and $E_{pot}$ the mass $m$ is inertial mass. It's the independence of $g$ on the mass of the falling object  which expresses the behaviour found by Galilei.
Answer: The $h$ in the formula $U=mgh$ is a height. So you can ask: a height from where? You need a reference.

The ball on the high shelf causes potential energy to be present when compared to the ground.
The ball in the ground causes no potential energy to be present compared to the ground - but it does when compared to the bottom of a deep hole.

The point is that potential energies of any form requires a reference. Their values are nothing more than a difference to the reference level.


Maximize number of assigned variables in constraint satisfaction

Question: What are some known algorithms (or resources to find algorithms) to find the assignment that maximizes the number of assigned variables in a constraint satisfaction problem (in case no satisfying assignment is present)?
Comment: You need to narrow your scope. What type of constraints are you talking about? Linear?
Comment: Yes, the constraints are linear.
Comment: Cool, then you should check out the Simplex Algorithm.
Answer: For linear equations, linear algebra can be used to find the number of degrees of freedom, and hence the number of assignable independent variables.
Edit:
Upon closer thought on you problem, I think the Simplex Algorithm might help you. It is an optimizing algorithm to find the best integer solution to a linear optimizing problem.
Edit 2:
Let the feasible region be the supplied depots.
Example:
Let's say you have 2 depot types, X and Y.
X requires 5 oil and 7 steel to be supplied.
Y requires 8 oil and 2 steel to be supplied.
You want to maximize the number supplied depots:
function to maximize  = X + Y
Conditions:
X <= total number of depots of type X
Y <= total number of depots of type Y
5X + 8Y < total oil supply
7X + 2Y < total steel supply
Apply the Simplex algorithm, and voila!
Comment: Well the simplex algorithm works on linear programming problems of  maximizing an objective subject to constraints. According to wikipedia, in case no feasible region is present, the possible results of Phase I of the simplex method are either a basic feasible solution is found or that the feasible region is empty. I'm looking for the maximum size feasible partial assignment in a constraint satisfaction problem in case there is no feasible complete assignment. How would simplex give me that?
Comment: I've added an example showing how I though. If I misunderstood your problem, please clarify your question further.
Answer: Could it be that you want to maximize the number of satisfied constraints, instead of assigned variables? I thought about what you might gain from maximizing the number assigned variables (until you trivially see at least one constraint violated), and it appears to me that you want something along the line of the largest subset of constraints that are satisfiable. Otherwise I probably don't understand your optimization criterion.
In case you want this largest subset of satisfiable constraints an idea is to convert your problem to a constraint optimization problem, find the assignment that minimizes the number of violated constraints, and then pick all those of your constraints which this assignment satisfies to construct a largest subset of satisfiable constraints.
I will use the framework of weighted constraint satisfaction problem (WCSP) in the following.
Given that you represent your constraints as tables of allowed or disallowed partial assignments, you can convert a constraint by simply assigning allowed assignments cost 0 and disallowed assignments cost 1. That is, whenever a variable assignment is not allowed by a constraint, it will incur a cost. The assignment that minimizes the costs consequently minimizes the number of constraints it violates, which is equivalent to maximizing the number of satisfied constraints. Once you have such an assignment it should be easy to construct a largest subset of satisfiable constraints by iterating over all constraints and check whether the assignment satisfies them or not. A good solver for WCSP is toulbar2, which computes such least cost assignments to a given WCSP.
Constructing a WCSP from your constraint satisfaction problem (CSP) is simple in case you do represent constraints as tables. Weighted constraints are just tables of the form
<code>X_1 X_2 … X_n   c

1    1 …   1    0

1    2 …   1    0

...

2    2 …   3    1

2    2 …   4    1
</code>
Here we have a constraint over n variables X_1, …, X_n, where variables may accept values from finite domains {1,2} and {1,2,3,4}. Assuming that you mark an allowed tuple with "T" and a disallowed one with "F", converting amounts to replacing the "T" with cost 0 and "F" with cost 1.
Note that this is not the actual WCSP format. The format is described in detail in the toulbar2 package linked above.
Of course, more compact representations of constraints will require a more elaborate conversion, which can grow arbitrarily complex depending on your representation. That is then the point where you might want to look into something else.
Comment: No, I'm not trying to maximize the number of satisfied constraints. I'm trying to solve a resource allocation problem to match resources to entities where the goal is to maximize the number of entities that have been allocated the required number of resources.


Can I ask about the full-time compensation package when receiving an internship offer?

Question: I'm worried about coming off as presumptuous, but at the same time it's a significant factor in deciding what internship offer to accept, as quite often an intern receives and accepts a full-time offer at the place they interned. From the company's perspective, however, asking about this likely comes across negatively, as I have not yet had the chance to work with them, so they wouldn't know whether or not they indeed want me as a full-time employee. So is it ever appropriate to ask about full-time compensation after receiving an internship offer? And if so, how would I phrase the question delicately?
Answer:
So is it ever appropriate to ask about full-time compensation after receiving an internship offer?

If you are thinking of asking "what is your starting salary for converted interns" than the answer is "no".
You can (and should) ask about hiring policies for interns up front. Some companies do convert interns, others do not and that can change over time (based in business needs and budget).
You can look up typical salaries and compensation satisfaction and sites like salary.com, glassdoor.com, etc. Salaries are freshers are pretty standard, so chances that you will find large variances there are small.
However, the money discussion should not start until there is serious talk about an offer for full time employment which would only happen towards the end of your internship.
Answer: It's entirely reasonable to want to know whether a company is merely offering some initial commercial experience in exchange for cheap labour, or is running a program to identify it's future junior hires.  Something along the lines of following would indicate your interest in a permanent role without being presumptuous about your performance leading to an offer.

I'm hoping to find an internship with the potential to lead to a permanent full time job. Does that happen at [company name]?  If it does, could you tell me a bit about the salary range and other terms and conditions for your junior employees please?


Change default products per page in search results

Question: When a user performs a search the default Magento search result pages offers pagination, it defaults to 9 items per page. I'd like it to default to 30 items per page.
How is this done?
Answer: You can achieve this by layout update. For this you need to follow these steps
Create local.xml file
This is a special layout file that will process by Magento after processing every other layout updation files. So this file is a perfect place to do "alteration" works.
File: app/design/frontend/<package>/<theme>/layout/local.xml
<layout>
    <catalogsearch_result_index>
        <reference name="product_list_toolbar">
            <action method="addPagerLimit"><mode>grid</mode><limit>30</limit></action>
            <action method="addPagerLimit"><mode>list</mode><limit>30</limit></action>
        </reference>
    </catalogsearch_result_index>
</layout>

Explanation Of Code
As you can see, we are using a layout handle catalogsearch_result_index, which is a unique handler for search pages. So any layout updates comes under this particular layout handle only affect in search result page. Next we have used an action addPagerLimit() in a block product_list_toolbar  in order to set the page size.addPagerLimit() uses two parameter for its internal operation. First parmeter specifies which list mode we need to alter. Basically there are two list modes. They are list and grid. Next parameter is the limit. This is used to set the toolbar size. So basically using our layout update, we set page size for all available list of modes that should only affect in search page.
Note: Don't forget to clear the cache
Answer: I think this is tied to the products in the category page, but i might be wrong. Values can be changed from
System > Configuration > Catalog > Catalog > Frontend

See this question also, it might be helpful if you only want to change the search.
Comment: You saved my day. I was looking everywhere else for this option!


Why don't we feel the Earth rotating beneath us?

Question: I'm not sure all of the details in the experiment but basically it went as follows. Someone marked their location of take off in a hot air balloon and went straight up in the air. They stayed suspended for some time before coming straight back down. Apparently the result was that they had not drifted from the original take-off point underneath them. Maybe I got all of that incorrect, but I'm sure it's close.
But if in that experiment the Earth had no effect on the landing point, why does the "rotation of the Earth" need to be factored into making the shot with a long range rifle for example? Now I know it isn't the best comparison and that there are many different factors in both scenarios. Such as "the bullet is traveling and in the experiment the balloon wasn't", but I'd just like to hear different theories and opinions as to why this is.
P.S. I know a popular answer is going to be that the Earth is too massive for us to feel its spin, but I'm thinking deeper than that!
Comment: It's a good question, but I'm not sure that an *astronomy* site is the best place for it - I think this is pure physics. Have you checked on our [physics.se] site to see whether there might already be a related question there?
Comment: I marked my seat while sitting in a train. I then climbed straight up into the overhead luggage compartment, and stayed there for some time before climbing straight back down. The result was that I ended up back in my marked seat; apparently the train wasn't moving at all!
Comment: On the other hand, if I throw a ball down the length of the aisle of the train, where it lands depends on whether the train is moving in a straight line, or whether it is making a sharp turn.
Comment: Related, but not duplicate: [Why don't we feel the speed of earth moving](https://astronomy.stackexchange.com/q/1998/7982)
Answer: There are two different things going on, and they aren't too related (from what I can see). For the hot air balloon situation, you would think that if you hovered above where you are for 6 hours, the Earth could spin under you, and you would land back in a completely different place. Unfortunately, because the hot air balloon was on the Earth to begin with, it was already moving with the Earth. There are many reference frames in play, even though we feel like we are standing still. Everyone on Earth is standing still on the surface. However, the surface is rotating around the Earth's axis. The Earth's axis (and the Earth itself) orbits the Sun. The Sun is goes around our galaxy and our galaxy is travelling through intergalactic space.
So how does this relate to the hot air balloon situation? Well because the balloon was on the surface, it was already moving with the surface of the Earth. Remember how I said that the surface of the Earth rotates around the Earth's axis? Well, since the balloon was on the surface to begin with, it will also rotate with Earth's axis, just like the surface! What if we wanted to achieve that hover effect? I said earlier that the Earth orbits the Sun. In order to achieve that hover effect, we would need our hot air balloon to orbit the Sun without rotating around the Earth. You can't do this with a hot air balloon, since the atmosphere also happens to move with the Earth, and hot air balloons can't go into space. To achieve that hover effect, we would need some sort of spaceship with lots of fuel. If I had a hovering spaceship that didn't orbit with the Earth (this would, again, cost lots and lots of fuel), then yes, I could hover in the same spot and have the Earth rotate under me.
Now, you're probably wondering how I could achieve this with a spacecraft that was originally on the surface of the Earth. There wouldn't be much point in this hovering effect since you may as well just fly to your destination (like the theoretical Big Falcon Rocket), but if you wanted to do it, you would need to go above the Earth's atmosphere, use your boosters to go opposite of the rotation of the Earth (to cancel out your velocity), hover for some time, then use your boosters to go along with the rotation of the Earth (to return to rotation velocity), and land on Earth. Of course, you could skip the 2nd part by using heat shields and ramming into Earth's atmosphere like every other spacecraft we have, and no rocket would ever do this as it's just much more practical to orbit around the Earth (hovering costs fuel, orbits don't).
Ok, what about the sniper situation? The Earth rotate on its axis. Since a day is 24 hours long, a location at the equator goes around once in the same time it takes for someone in the arctic to go around once. However, the further north or south you are from the equator, the slower that part of the Earth has to rotate to complete 1 rotation in 24 hours. Think about spinning a ball. The equator of the ball whips around, but the top and bottom move much slower. It's the same thing. Lets say my sniper is at the equator. When the sniper shoots east or west, they do not need to correct for the Earth's rotation because everywhere along that latitude, the Earth is rotating at the same speed. However, if the sniper shoots north, the bullet will go to the east. That's because when the bullet was shot at the latitude closer to the equator (shot from the south), that spot of the Earth was moving faster than the spot of the Earth that the target was standing on. It's like saying that the spot I'm standing rotates at a speed of say... 1000 mph, but my target's spot rotates at say...995 mph. Since my bullet came from the 1000 mph part, it will obviously go out of the barrel at high speeds because of the gun, but it will also be rotating around the Earth's axis at 1000 mph. However, once my bullet starts approaching my target's latitude, since the Earth rotates slower, it will appear to deviate in the direction of the rotation (which is east, or to the right). Why? Well since my target's speed is 995 mph from rotation, you do 1000 - 995 = 5. That means that my bullet will have a net velocity of 5 mph to the right relative to my target. That means my bullet will miss if the target is far away enough. If you shoot from the equator to the south, the bullet will also go east, so as a result, it will deviate to the left. It's the same effect, but "upside down". This effect is called the Coriolis effect, and it's what gives hurricanes their power.
Finally, you asked "why don't we feel the Earth rotating beneath us?" This is because we are moving with the Earth. When you are on a train that is going at a constant speed of 50 mph, you do not feel it move (you may feel some bumps due to bumpy tracks). It is only when you accelerate or decelerate do you feel things move. When you are on the train, your speed is constant, so you do not feel anything. It's the same for the Earth, except you are rotating around the Earth's axis at a constant 1000 mph. Nothing has changed, except the speed is faster.
I probably explained this horribly so feel free to ask anything.
Comment: You explained it very well and in great detail, thank you!
Comment: @Begons18 Let say I go bowling on a train (it's a big train). The train goes 50 mph to the right. There are 2 bowling lanes, one that faces left and one that faces right. If I always bowl at 10 mph, then when I bowl to the left, it will go 10 mph left relative to the train, but 40 mph to the right relative to the ground. (50 - 10 = 40) If I bowl to the right, it will go 10 mph right relative to the train, and 60 mph relative to the ground. (50+10=60) Change the train with the Earth spinning 1000 mph east at the equator and a gun that fires 1500 mph. The situation stays the same.
Comment: @Andreas Hurricanes cannot cross the equator. They would disappate before they got there because there isn't any supporting coriolis force to keep it spinning. A few years ago typhoon vamei developed only 1 degree north of the equator, setting a new record. Apparently, though not particularly powerful, it was so rare that it was estimated to be a 400 year storm.
Comment: A rocket does not need to go to space for this to work. Go straight up and straight down without leaving the atmosphere and you still don't come down at the same point. it only works with the balloon because the balloon stays in the very dense parts of the atmosphere and he balloon is very light compared to the surrounding air and gets pushed along easily.
Comment: But, I do have some questions. Bare with me here. You said in the experiment he didn't move because he was on the surface to start with so he was moving at the same rate as the earth beneath him. Just like when a car is moving, the person in the care is going that same speed. But let's say you're standing at the equator, and you fire a bullet in the opposite direction of the rotation of the earth. The bullet would still leave the barrel and travel at its intended speed wouldn't it? Why is that?
Comment: If I'm driving in a car going let's say 1500fps and I fire a bullet in the direction of that travel, what would happen if the bullets top rated speed was 1500fps? You're moving at the same speed of the bullets top speed but would it exit the barrel? If you exit a car while moving, you still exit that vehicle at the same speed it was moving to begin with correct?
Comment: I hope my questions aren't a bother to answer and seem logical in your mind. I mean after all you'll never get an answer to a question never asked correct? Thank you for teaching me!
Comment: @Begons18 Concerning your bullet question, it also your bullet was rated 1500 fps, probably relative to the air. If I shoot in front, relative to the air, your bullet will go 3000 fps (1500 fps from car + 1500 fps from gun), so your bullet might shatter.  If I shoot behind the car, relative to the air, your bullet will go 0 fps. (1500 fps - 1500 fps) Since gravity still pulls down, it will fall down normally (like bullet drop), but your bullet won't have a net horizontal velocity. Feel free to search up "Mythbusters cannonball truck" on youtube for this in action.
Comment: @Begons18 Not a problem.
Comment: Hmm... Do hurricanes dislike crossing the equator?
Comment: "the atmosphere also happens to move with the Earth": this is the most significant factor in the hot air balloon experiment.  @Polygnome it's less that the balloon is pushed around very easily and more that the coriolis forces are negligibly small.
Comment: "there isn't any supporting coriolis force to keep it spinning": Coriolis forces do not keep hurricanes spinning.  They are too weak.  They only determine the direction of the spin.  The force driving the spin is the vertical air circulation, which creates a low pressure area causing surface air to flow toward the center.  See https://en.wikipedia.org/wiki/Tropical_cyclone#Secondary_circulation:_a_Carnot_heat_engine.  The reason hurricanes do not cross the equator is not that a lack of equatorial coriolis force would cause them to dissipate, but that the coriolis force pushes them poleward.
Comment: @phoog Its both, the coriolis force is small, but a balloon has a very low density, especially compared to a rocket. the weak coriolis force is able to move the baloon, but not the rocket.
Comment: @Polygnome perhaps.  It depends on the frame of reference.  From the frame of reference of the earth's surface and (still) atmosphere, the force is too weak to move the balloon noticeably in light of its high drag (which is more significant than its density). In fact the coriolis force *does* affect rockets, which is why they are launched near the equator.  The reason the coriolis force does not appear to affect the rocket is that the rocket is traveling much faster than the balloon.
Comment: @phoog would it be correct to say that coriolis force is what initially kickstarts the spin?
Comment: @KITTENDESTROYER-9000 I believe so, but I am no expert.  As I understand it, the air moving toward the center of low pressure is deflected by the coriolis force, initiating the spin.  But in fact even if it weren't deflected, the air wouldn't rush *exactly* toward the center, so it would end up spinning anyway. Without the coriolis deflection, though, there would be an equal chance of spinning in either direction, so the deflection guarantees that the spin is counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.
Comment: I have a problem with your last paragraph. The train analogy is not exact, because the train is supposed to be an analogy of motion in a straight line with constant speed, i.e. in an inertial frame of reference. However, rotation is non-inertial, with constant acceleration. And humans *can* feel acceleration, and rotation in particular, even if in a windowless laboratory. Accordingly, in theory, humans *should* be able to sense the rotation of Earth, even if standing in a windowless lab. Considering that Earth rotates fast at the Equator, it is not trivial why we do not sense it with our body.
Answer: It's hard to feel the Earth's rotation personally, but only because we are not very sensitive to very gradual changes and very weak "forces". However, there are everyday objects that can show us the rotation of the Earth. The balloon may have been a bad choice because even a slight wind over time will dominate the problem. (also see]
A pendulum
One object is a Foucault pendulum.
 Source
A gyroscope
Another is an (expensive) camera with inertial image stabilization. Some cameras have small gyroscope chips that sense very tiny rotations of the camera body and compensate with image processing.
 Source
See the following questions and their answers for more on this.

SLR camera gyroscopic stabilization - limited by rotation of the earth?
Why does Image Stabilization have a Limit?
Comment: This is a GREAT answer.
Answer: That's three questions in one.

Why don't we feel the earth rotating beneath us?

If you're asking what one feels when standing still on the surface of the Earth, it's because

Static friction and the normal force are constraint forces,
The difference between what you would feel on a nonrotating planet with the same mass and size of the Earth and our rotating Earth us very small, and
You've never experienced anything but standing on our rotating Earth.

Constraint forces take on whatever value is needed to satisfy the constraint if doing so doesn't violate some other condition. For example, the normal force pushes normal to the surface so as to keep the constrained object on the surface (the constraint). The "other condition" in the case of the normal force is that the normal force can only be directed outward. Friction comes into play if the surface on which one is standing isn't level. The other condition in the case of static friction is that it can't exceed the coefficient of static friction times the normal force.
So, what values do these forces need to take on to keep you standing still on the surface of the Earth? From the perspective of an inertial frame, an object at rest on the Earth's surface is undergoing uniform rotation about the Earth's axis. This means the net force on the object must be inward, toward the Earth's axis of rotation (note well: not toward the center of the Earth, except at the equator), and have a magnitude of $F_{\text{net}}= m r \Omega^2$, where $m$ is the object's mass, $r$ is the distance to the axis of rotation, and $\Omega$ is the Earth's sidereal rotation rate. The other forces acting on the object are gravitation and buoyancy, which is very small. Ignoring buoyancy, we must have $\vec F_\text{surface} + \vec F_\text{gravity} = \vec F_\text{net}$. The net force is largest at the equator, where it's very small compared to gravity, about 0.3% of gravitational force. In other words, the upward force exerted by the Earth's surface and the downward force exerted by the Earth as a whole are nearly equal to one another.
The same result arises if one looks at things from the perspective of a rotating frame. From this perspective, the apparent net force is zero. Rotating frames involve fictitious forces such as the fictitious centrifugal force. This has the exact same magnitude as but the opposite direction of the net force calculated above. The end result is the same.

Someone marked their location of take off in a hot air balloon and went straight up in the air. They stayed suspended for some time before coming straight back down. Apparently the result was that they had not drifted from the original take off point underneath them. Maybe I got all of that incorrect but I'm sure it's close.

That's the second part of the question. Unless tethered, hot air balloons typically do not return to the spot from which they take off. Hot air balloons go wherever the wind carries them. That's why hot air balloons need chase teams. A hot air balloon will return to its take off point if the wind is nonexistent or if it reverses direction during the course of the balloon's flight. The buoyancy that I ignored above is anything but negligible for a hot air balloon. Here it's the normal force that is negligible (it's nonexistent). For a balloon to remain stationary, the wind needs to be nonexistent and the buoyancy force must take on the same form as the normal force takes for an object sitting still on the surface of the Earth.

Why does the "rotation of the earth" need to be factored into making the shot in a long range shot from a rifle for example?

Because the bullet is moving with respect to the surface of the Earth. Note well: It's only the very long range shots, more than a kilometer, where the Earth's rotation needs to be taken into account. The motion of the bullet brings another fictitious force into account, the Coriolis effect. The Coriolis effect is zero for a stationary person and for a stationary balloon.
The Coriolis effect has two primary effects on the flight of a bullet, a horizontal deflection and a vertical deflection. The horizontal deflection depends on latitude, the effect being strongest at the poles and zero at the equator. The Coriolis effect makes moving objects turn to the right in the northern hemisphere but to the left in the southern hemisphere. The vertical deflection depends on latitude and direction. This vertical deflection is strongest at the equator, zero at the poles or if the direction of motion is to the north or south. The deflections are small, even for a bullet fired toward a target a kilometer away. Centimeters however can be important.
Comment: Although centimeters can be important, for sniper shots (about 2 km or less), Coriolis effects are swamped by other error effects, so it's not normally compensated for. Long-range artillery, on the other hand, can feel the need to compensate, and rocket artillery, with even longer path lengths (and more importantly, longer flight times), will correct for the effect.
Comment: "The Coriolis effect makes moving objects turn to the right in the northern hemisphere but to the left in the southern hemisphere. ... This vertical deflection is strongest at the equator": this can't be right. If it were correct, the strongest rightward deflection would be felt by a bullet fired parallel to and infinitesimally north of the equator, while the strongest leftward deflection would be felt by a bullet fired on a parallel track infinitesimally to the south. In fact, both will be deflected towards or away from the origin, depending on whether they were fired eastward or westward.
Comment: @phoog - What I wrote is correct. Perhaps not best written, but correct. The eastward, northward, and upward Coriolis accelerations are $v_n\sin\phi-v_u\cos\phi$, $-v_e\sin\phi$, and $v_e \cos\phi$ where $\phi$ is latitude and $v_e$, $v_n$, and $v_u$ are the eastward, northward, and upward components of the object's velocity. Bullets fly more or less horizontally (the vertical component of a bullet's velocity is small compared to the horizontal component), so the $v_u\cos\phi$ portion of the eastward Coriolis acceleration can be ignored. ...
Comment: This means that the horizontal deflection is proportional to $\sin \phi$, which is zero at the equator and one (or minus one) at the poles, while the vertical deflection is proportional to $\cos \phi$, which is one at the equator and zero at the poles.
Comment: I see.  I missed the change of gears in your answer from horizontal deflection (moving to the left or right) to vertical deflection (which is strongest at the equator).  The horizontal deflection is weakest at the equator, which makes sense if that's where its direction reverses, but I misunderstood that you were asserting to the contrary that it is strongest at the point where its direction reverses.

Why don’t we feel the Earth rotating beneath us?


Using Integrate tool to "snap" points

Question: I am using ArcMap 10.4.1 for desktop.
I have two layers with points in them and I am trying to get the points of layer A to "snap" to the closest points of layer B. I am using the Integrate tool with a tolerance value that should match the greatest distance between the points of the two layers. The tool will run fine but the end result is that the points in both layer A and B are changed rather than just the points in layer A snapping to layer B. Any idea what is going wrong here?
Comment: Welcome to GIS StackExchange!  As a new user, please be user to [take the tour](https://gis.stackexchange.com/tour).
Comment: The Snap Tool in Editing Tools might be a better choice than Integrate.
Comment: I think a picture showing what you start with and the result you are getting versus what you want would be helpful.
Answer: Try adjusting your xy tolerance, as ArcGIS Help indicates this situation will occur when the tolerance is too large:

The feature class or layer with the lower rank will snap to the feature from the feature class or layer with the higher rank (with 1 being a higher rank than 2). Note that features in the feature class with a rank of 1 may move when a large x,y tolerance is used.

You may wish to try a different tool, such as Snap. Warning: both Integrate and Snap will change your input dataset(s). Here's a similar question related to the Snap tool: Is there an alternative to the Integrate tool that will not change one of the inputs

Using Integrate tool to "snap" points


How to set a different input method for each app window

Question: How can I have a different input method for each app window on windows 8. When I change input language to ENG all app window also uses this method and I don't want that. Like windows 7 that has a different input method for this purpose. thanks
Answer: Update for Windows 10 at least 1809:
Switcher Let me set a different input method for each app window was moved to

Settings -> Time&Language -> Language -> Related Settings: Spelling,
  typing, & keyboard settings -> More keyboard settings: Advanced
  keyboard settings
Comment: Microsoft moved it again... Settings > Time & Language > Region & language > Advanced keyboard settings
Comment: ...and again: in Windows 10 21H2 it's at Settings -> Time & Language -> Language -> Keyboard -> "Let me use a different input method for each app window" ([from user Sergey](https://superuser.com/a/1732342/272824)).
Comment: In Windows 11 23H2 the location is Settings > Time & Language > Typing > Advanced  keyboard settings
Answer:
First, you need to access the Control Panel. There are several ways to open it.
You can right-click at the bottom left of the screen, and then choose Control Panel from the list.
Alternatively, you can access it from the Charm bar. Move your mouse to the bottom right of the screen, and then choose Settings from the slide-out bar.
You can also launch it from the Computer tab in the Explorer window.
In the Control Panel window, find the Language option. Use the search feature if you have trouble finding it.
Once you are in the Language section, click on the Advanced settings option, which is located on the left side of the window.
Finally, find the Switching input methods section, and turn on the Let me set a different input method for each app window option to be able to configure input method for each app.
When you are done, click the Save button to preserve the changes.
With the option enabled, go to the app for which you want to use a different input method, click on an input field, and then switch the input using the language bar.
Later, if you want to use a universal input method for all apps, simply turn off the Let me set a different input method for each app window option.
Comment: What is the method to do this on win 7 ?


Can Reavers reproduce?

Question: Can the Reavers in Firefly/Serenity reproduce or otherwise grow their numbers, or are they stuck, always losing numbers? I'm not really counting the ones produced occasionally during a raid, but a more consistent method of reproduction.
Comment: They don't reproduce in the sense of having tiny ragebabies, but converting people into raiders could be considered reproduction.
Comment: @Ian upvoted for "ragebabies"
Comment: in my opinion, @IanPugsley, you gave the actual correct answer. it even has more votes than the accepted answer
Answer: I believe the original Reavers' numbers have been dwindling ever since

 the incident on Miranda, where only 0.1% of the settled colonists had the violent reaction to Pax.

and much of their ranks now consist of converts.
The reasoning:

Due to the reason stated above, their original numbers should have been in the thousands.
They may be able to fly and maintain ships, but I really don't see them raising children.
It is difficult to tell how long ago the events took place. River was somewhat younger when she was exposed to the secret and the skeletons of the colonists seemed old. The scare stories about Reavers seem to be at least a generation old, judging from the way they're being told.
They convert by subjecting some of their victims to psychological torture.
Comment: They really don't seem to be the nurturing type - also, the Firefly wiki states a Reaver population of around 5,200 http://firefly.wikia.com/wiki/Miranda
Comment: @Pearsonartphoto: So, if there's 5,200 now, that would indicate to me that they don't reproduce often or very well, having lost 5/6 of their population.
Comment: I could swear that I heard the population of Miranda was 30 million somewhere...
Comment: @Jeff: 25000 out of 30000 as casualties seems plausible, given their lifestyle, lack of tactics, lack of reactor shielding...
Comment: Well, it's important to distinguish "can" from "do." Reavers are entirely human, so aside from physical malfunction they are just as capable of reproduction as any other human. For the excellent reasons stated above, they probably **don't** reproduce biologically, even though they **can**.
Comment: Agree with @Matt - I think they can.  They also probably eat babies, so "reproduction" is likely moot.
Comment: 5.2 million does sound about right for a colony of modest size.
Comment: I agree - particularly with the obvious tech level of the city we see in the movie.
Comment: @Pearsonartphoto That's what it says on [Wikipedia](http://en.wikipedia.org/wiki/List_of_Firefly_planets_and_moons#Miranda), but the Firefly Wikia only lists the Reaver population
Comment: @Izkata: I'm going to have to go re-watch Serenity just to see if it is quoted in the movie or not...
Comment: @Izkata: 30 million population, .1% became revears. That means there's around 30K Revears, at least to begin with...
Answer: I just watched the movie and the lady on the movie said the population of Miranda was 30 million.  She also said that 0.1% ("a tenth of a percent") of them became Reavers.  Doing the math that is 30,000 Reavers.  They probably just kept torturing and making more reaver guys like zombies or Will Smiths favorites?
Comment: +1: 30 Million; -1: It was 0.1% with a negative reaction.
Answer: What if the main goal of the Reavers is conversion? Couldn't that also mean that they could have consistent means and perspectives on how to care for their "ragebabies?" Could they not, for example, have a different perspective on how to interact with those who have not reached puberty and who were born to a Reaver mother? Some kind of coming of (r)age ceremony? There use of advanced technology obviously shows that their ability for critical thinking is not lacking, and that they should not be viewed as simply mindlessly aggressive.
I think what could be interesting to consider is if Reavers have a consistent perspective on life. For example, the self-mutilating could be a method adapted by Reaver leaders in Miranda for fighting against the pacifying effects of Pax, and later become a Reaver cultural norm. Furthermore, the Pax drug could have been modified by Reaver scientists (they already demonstrate advanced tech understanding) to make the process of converting a "normal" human into a Reaver  (think like the drug in Deadpool, a drug that combined with trauma to trigger a biological response). Imagine that some of the original Reavers (although probably already insane) saw the effects of pacifism and decided to make war on this pacifism, and with a religious fervor made it their life mission to "wake up" or convert to Reavers all those who seemed to be pacifists. The reason that that Reavers act the way that they do could be because it is expected in their society, seen as necessary to be shown not to be a pacified one, and for a variety of other social conditioning reasons.
With a coherent ideology, a modified Pax-based drug, and a religious zeal, there is no reason why they would not be able to either have a much higher conversion rate than 0.1% and/or have a social structure that could, at least, allow for outsiders to care for their "ragebabies."
One of the critical structures for creating a coherent cultural ideology, as described in The Pervert's Guide to Ideology, is enjoyment (jouissance). This is distinct from simple pleasure in that its excess can be described as pain by those outside the ideology. Think about how some say that fear or violence makes them feel alive, and can even think of themselves as superior beings.
Of course, a critical element is that a potential convert should have a perspective of themself that allows them to contextually fit into Reaver society and to perform the actions that will be required of them. Not all people will be able to make the transition, even with chemical enhancement, but there have always been people in society, for example — in early human societies, they were the hunters — the ones that would enjoy making the final killing blow in a hunt. Some of this layer became serial killers, others would be enlisted for certain military functions. The first explanation (Season 1 Episode 2) for a human/Reaver convert is that the only way to cope with the horrors that are seen is to become the darkness. This rather rushed explanation combines, in my estimation, perhaps a kind of Stockholm syndrome and an understanding of how a person internalizes trauma (and how they can take it to mean something about who they are). Although this a bit of sloppy explanation it does come around the same time that the horrors of war are mentioned, and I think this is a better place to look for a coherent explanation (think village massacres in Vietnam). Human beings are pliable both socially and neurologically, and to lose perspective on how they are fit to one nefarious purpose or another is to lose perspective on how one may be fashioned into a living biological weapon again.
I am only posing one of many possible coherent ideologies for the Reavers. I am curious if others think this fits the way that Reavers are portrayed in the show, or if they see other ways that it might be a coherent social grouping and retain their skill with advanced technology, and solve the problem of reproducing their numbers.
Comment: I think perhaps you could do with putting some headings in to show where you're: **1, answering the question with a short 'yes, but...' or 'no, but...'** and  **2: putting across your wider theories** (although I believe this site prefers source-based answers rather than speculation and discussion).
Comment: You should visit http://browncoats.com and seek a receptive forum for these ideas; some of them are quite fascinating.
Comment: It is an interesting theory, but it's a bit rambling and speculative.

Can Reavers reproduce?


Why are Arabian Nights set mostly in Persia?

Question: I liked the tales of Arabian Nights from childhood and re-read them many times through my life. What strikes me as odd, is that all the main characters are predominantly Persian. Moreover Arabs (e.g. a recurring theme is an evil Maghreb mage) are sometimes are cast as evil and unfaithful. If a person is from Maghreb it's a good enough reason to distrust them, according to the narrative. But these are folk tales, and they were written in Arabic, not in Persian! How is this historically explained? Surely Persians would have written it in Persian, and Arabs would not make Persian the protagonists?
Comment: From the second paragraph in your link to wikipedia, "Many tales were originally folk stories from the Abbasid and Mamluk eras, while others, especially the frame story, are probably drawn from the Pahlavi Persian work Hezār Afsān".

Can you please read the wikipedia article attentively, and state explicitly what is missing so that we can answer it here?
Comment: The Maghreb by the time of the Abassids had slowly separated from the rest of the zones colonized by the Arabs. This separation might have been seen by the time as a treason by the Abassids, thus triggering this picture of Maghreb people as evil and unfaitfhul.
Comment: Maghreb only means "west" in Arabic. Can we be sure that what is referred to as "West" in that literary work is actually the same area we call Maghreb today?
Comment: The title of your question is rather poorly chosen, IMHO. It would probably be better to call it "One Thousand and One Nights", which is its original title, and the title it is best known by for everyone who is not a *native* English speaker (and I guess even a few of those). This also avoids a casual reader thinking that your question is (also) about the title, instead of the language and the character depiction. Then again, that link to WP basically answers your question already -- it is not an *original* Arabic work, but a collection of *existing* stories.
Comment: @AstorFlorida I would imagine that if something has "roots" in a neighbouring area it would still be adapted so that the protagonists become "our folk". E.g. the Cinderella story was once about a [Greek slave girl who marries the king of Egypt](https://en.wikipedia.org/wiki/Cinderella), but of course she is no longer Greek, etc
Answer: The correct question would be "why is it called Arabian Nights". The answer is that this was a decision by the English translators, and has little to do with the original work. As explained in the second sentence of the wikipedia article you linked to.
Suppose someone would decide to translate the Song of Roland into English and give it the title "The Song of the French". Should we then ask why the work is mostly set in Spain?
One thing to keep in mind re. Persians is that the Abbasid court in Baghdad was located only a few dozen kilometers from where the (Persian) Sasanian court had been located earlier (and before that the Parthian and, for some time, the Seleucid court), in Ctesiphon. A story set in Baghdad, but several hundred years earlier, would automatically have been set in the Sasanian capital.
Comment: It's not just the name, it was written in Arabic language not in Persian.
Comment: @AndrewSavinykh Yes, it is common that literary works written in language A are set in a country where language B is spoken. As mentioned above, the Chanson de Roland is one such example. [Aladdin](https://en.wikipedia.org/wiki/Aladdin) is another one: originally written in France and in French, but set somewhere in the Orient. The uncommon thing here is the title, not the setting.
Comment: @AndrewSavinykh Asterix might be a more relevant example. Set in what today is France, but in a time when the language of the protagonists would have been quite different from French. Might some translator publish it under the title "The two French Bros"? Possibly. Would it be surprising that the stories are set in a world where everybody speaks Celtic or Latin instead of French? Not really I think.


Start cheek kissing on the left/right side

Question: Cheek kissing is a very discussed topic in each site like this, because it is quite different depending on the country (number of kisses (especially), when to cheek kissing, men/women...) and it is a thing a foreigner will do even in a short stay. There is a lot of information on the internet about each country culture respect of it, like this map of France.
I didn't ever think about which side should be kissed first, until I moved to (southern) Italy and I had a few of embarrassing situations because here they start kissing left cheek, i.e. moving the head to the right. It is even more embarrassing when men also cheek-kiss here.  Then I realized in Spain we always start kissing right check.
But I didn't find information (regarding a few sentences on Wikipedia) about this matter. Is it any cheek-kissing-depending-on-countries collection including it? Maybe it is more stablished in countries with an odd number of kisses?
Comment: https://i2.wp.com/www.johngrimwade.com/blog/wp-content/uploads/2016/09/kisses.jpg
Answer: I am French and I never thought of which cheek should be first kissed! I don't think there is a definite rule. The protocol I identified is:

first protagonist tends his or her cheek (left or right)
second protagonist adapts and tends the same cheek.
if it fails, both smile or laugh and the procedure starts again

As for the number of kisses, when people don't know each other's habit:

one protagonist thinks it's enough and starts to stop the game
the other one goes on playing
both smile saying something about regional differences
then they agree on either the short or long protocol
Comment: it sounds very analytical, almost robotic, but this is the exact process indeed. I can tell that when you have half your family giving 2 kisses, the other half 3, you smile a lot when you visit them :)
Comment: I agree with this answer, and let me also add that I have southern-Italian roots. There is no "protocol" about it
Answer: Cheek kissing - Wikipedia and How to air kiss - Wikihow gives conventions about kissing in diffrent countries, precising it's often the right cheek first.
("Air" kiss because your lips don't actually go on the cheek, it's more cheek-on-cheek and you make the noise with your lips.)
Only for France, combiendebises.com gives stats for each department about the number of kisses, and which cheek to give first (droite = right, gauche = left).
One can see that it's more often the left cheek in the south and the right one in the north.
(If you click on a department they ask you for the kiss count, which cheek goes first, your gender and which gender you kiss when you don't know the person.)
(There is also combiendebises.free.fr only for the number of kisses, but more voters.)
Comment: I talked about Wiki article on the question, it only appears information (of which cheek should be kissed first) of a few countries. Wikihow is not completely right information when saying Italy is right cheek first (maybe in the north). But, French website is amazing! And French culture too complicated. Thank you!
Answer: In the countries of the Levant (especially Lebanon, Syria, Jordan), cheek kissing is quite common. Depending on the situation, it might not be appropriate to cheek-kiss a member of the opposite sex.
However, in some areas such as the coastal part of Syria and most of Lebanon, or in case you're close friends or relatives, it's also common to cheek-kiss a member of the opposite sex.
The Lebanese cheek-kiss is performed by touching the cheeks and kissing the air. Starting with the left cheek, the right cheek, and ending with the left cheek, totaling 3 kisses.
The Syrian cheek-kiss starts on the right side, then the left side, in the last kiss that ends on the right cheek, a single more emphasized air-kiss or a double air-kiss is performed.
Update: Answering the question in your comment is not as easy to answer as one would think. As you probably have noticed in my answer, cheek kissing is common in places that were under the French mandate. In Lebanon the kissing starts on the left side. In Syria, Tunisia, Algeria, Morocco, the kissing starts on the right side.
Just keep in mind that the cheek-kissing isn't very deep in the Arab culture, so most people won't be offended if you start on the wrong cheek, you can consider it an ice breaker.
Comment: @HaLaBi Unfortunately, I don't have enough information about other Arab countries when it comes to cheek kissing. Feel free do edit the answer and include the ones you know.
Comment: @Adnan Thank you for the information, anyway I was focused just in which cheek starts. Is it left-cheek first in all Middle East countries? (also for @HaLaBi)
Comment: @machlas I've corrected my answer regarding Syria, I've also tried to answer your comment.
Answer: In Jordan cheek kissing always starts on the right cheek and moves to the left.
Answer: In the Netherlands, it's exactly 3 kisses, starting with the right cheek. Not between men.
As a man, it's absolutely not done to cheek kiss a woman who'd rather not, so you take a tiny bit of initiative and then see if the movement is continued, otherwise just shake hands. When in doubt, just shaking hands is always fine as well.
Answer: In Kuwait, Saudi Arabia (probably also Bahrain):

Close friends? left, right, left - this is the most common, air kiss.
Informal colleague? left only (of the person being kissed) along with a handshake. So you shake hands and give an air kiss on the left.
For close family relatives, air kisses between sexes is allowed; but its rare.
For elders (for example, your grandmother or grandfather, or the grandfather of your close friend), on their forehead, and its a kiss.
For elders, but you do not have the protocol to kiss on the cheek or the forehead, you kiss on their right shoulder. This is usually done when meeting someone of extreme prominence (like the Emir) and only by other Arabs, never by foreigners (who just shake hands).
Answer: In hungary we kiss each other on the left cheek which is contrary to lot of southern and western european countries. And it CAN cause a problem when your noses bump into eachother becase the other person starts with his/her right cheek.
Answer: For Catholics it is usually two kisses. Starting on left. So left then right.
For Orthodox it's three kisses starting on right. So right, left, right.
But kissing is always only for those who know you and who you know. Either close family or close friends. Anything other will likely be very offensive and intrusive. So don't just go around kissing people unless it's a joke and they know it's a joke. You might get yourself in trouble you don't want to be in. Otherwise people are pretty easy going for the most part. Obviously some are conceded assholes. So just use your best judgment.
Comment: @pnuts Yes, you are right
Comment: @pnuts cheek kissing means that you kiss a cheek of somebody. And when you're kissing left cheek, your left cheek also is being kissed. What's your question?
Comment: @pnuts I'm thinking you are trolling. Both people select left from their point of view, and yes, these cheeks are "right" from the other participant.
Comment: I know many catholics who do 4. You should specify which area you think your rule is valid in.


A corollary of Mermin-Wagner Theorem

Question:
The picture above shows Mermin-Wagner Theorem and its corollary.  How can the corollary be derived from Mermin-Wagner Theorem?
Answer: The corollary can be inferred from the Goldstone theorem:  If the ground state breaks a continuous symmetry, there are gapless excitations.  Thus, if the system is gapped, the symmetry cannot be spontaneously broken in the ground state.
This does, of course, not explain how the corollary follows from the Mermin-Wagner theorem (and it holds in any spatial dimension).

A corollary of Mermin-Wagner Theorem


Does an inflatable heat shield have some capacity to be used for LEO Earth's atmospheric entry?

Question: It was originally designed and tested by NASA for Mars missions.
In my case, it does not have to work 100%. Even if it survives for only 1 minute or so, during atmospheric entry - it could add some value to an asteroid mining mission.
Comment: While I appreciate the accepted answer tick, it is generally a good idea to wait at least 24 hours for people in other timezones to have a look, it may turn out there are newer/better design studies or that I completely malfunctioned the math.
Comment: I am looking for a way to decrease the chances of a 100-ton metallic asteroid (piece from it) breaking apart during atmospheric entry.
Comment: @GremlinWranger - good question. I was not thinking about that part. I thought Earth's gravity assist will be sufficient to get on LEO.
Comment: @GremlinWranger -  thank you very much. Do you think I will be ridiculed if I bring up the option of using an inflatable heat shield in Earth's atmosphere? Some people tell me that this is a nonstarter, because it was designed for a thinner  Mars atmosphere.
Comment: @GremlinWranger - Thank you!!! I am updating my article accordingly.
Comment: @GremlinWranger - You were very generous. The details you've provided and the reference to "Advanced European Re-Entry System" were very important for my article.
Answer: For LEO the answer appears to be a qualified yes.
This design study looks at recovering the 150 kg Vega upper stage using a 4.5 meter diameter system. Scaling for area to get 100 tonnes that looks like a 50 meter radius.
This is notably larger than the 100 tonne space shuttle orbiter with a 23 meter wingspan, due to the larger heat flux that could be tolerated. If a more robust design is possible the area can probably be reduced closer to the 37 by 23 meter shuttle.
Engineering a 50 meter structure that is inflatable is probably not possible but assuming robotic or human assembly presumably already required to load the asteroid into the system a flat pack solution using the same flexible heat shield surface with an assembled supporting structure probably is achievable, possibly also allowing a higher heat loading and therefore smaller dimensions.


How can I import a raw RSS feed in C#?

Question: Does anyone know an easy way to import a raw, XML RSS feed into C#?  Am looking for an easy way to get the XML as a string so I can parse it with a Regex.
Thanks,
-Greg
Answer: This should be enough to get you going...
using System.Net

WebClient wc = new WebClient();

Stream st = wc.OpenRead("http://example.com/feed.rss");

using (StreamReader sr = new StreamReader(st)) {
   string rss = sr.ReadToEnd();
}

Comment: Or just call wc.DownloadString("feed url");
Answer: If you're on .NET 3.5 you now got built-in support for syndication feeds (RSS and ATOM). Check out this MSDN Magazine Article for a good introduction.
If you really want to parse the string using regex (and parsing XML is not what regex was intended for), the easiest way to get the content is to use the WebClient class.It got a download string which is straight forward to use. Just give it the URL of your feed. Check this link for an example of how to use it.
Comment: Interseting article. I need to start looking into WCF and the Syndication API.
Answer: I would load the feed into an XmlDocument and use XPATH instead of regex, like so:
XmlDocument doc = new XmlDocument();

HttpWebRequest request = WebRequest.Create(feedUrl) as HttpWebRequest;

using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
    StreamReader reader = new StreamReader(response.GetResponseStream());
    doc.Load(reader);

    <parse with XPATH>
}

Answer: What are you trying to accomplish?
I found the System.ServiceModel.Syndication classes very helpful when working with feeds.
Answer: XmlDocument (located in System.Xml, you will need to add a reference to the dll if it isn't added for you) is what you would use for getting the xml into C#.  At that point, just call the InnerXml property which gives the inner Xml in string format then parse with the Regex.
Answer: You might want to have a look at this: http://www.codeproject.com/KB/cs/rssframework.aspx
Answer: The best way to grab an RSS feed as the requested string would be to use the System.Net.HttpWebRequest class.  Once you've set up the HttpWebRequest's parameters (URL, etc.), call the HttpWebRequest.GetResponse() method.  From there, you can get a Stream with WebResponse.GetResponseStream().  Then, you can wrap that stream in a System.IO.StreamReader, and call the StreamReader.ReadToEnd().  Voila.
Answer: The RSS is just xml and can be streamed to disk easily.  Go with Darrel's example - it's all you'll need.

How can I import a raw RSS feed in C#?


How to create a reusable rdlc template?

Question: How to create an rdlc template so that we can use it for all the rdlc files in a project reducing the time to format each and every rdlc file. is it possible to create a rdlc template by which we can have the header to all rdlc files as same as rdlc template by inheriting it??
Answer: SSRS for SQL 2008 R2 added some features for using reusable queries (DataSets) and Report headers.  The two caveats to this technology is that 1) You can only render these reports via SSRS 2008 R2 (not via the .net reporting controls for Winforms or Webforms), and 2) you need to edit them via Report Builder 3.0 (which requires elevated permissions to SSRS).  It will not work with BIDS (VS2008).  I have heard that you might be able to edit the new RDLCs by getting an add-on for VStudio 2010 or by using VStudio 2012, but I cannot confirm this.
Answer: I usually use a good compare tool, like Beyond Compare, and merge everything from my template into the new report.
It's not that fancy but works. Plus you get a good insight to how reports are defined.
Answer: This is usually done through Sub-Reports for Header and Footer.
Is it possible to reuse a header or footer in ReportViewer in Visual Studio 2010?

How to create a reusable rdlc template?


Using 'diff' command over ssh

Question: If I have a folder with several files on my computer, and a copy of the same folder on a remote server, is it possible to run 'diff' through ssh so I can see the differences between my copy and the one on the remote server? Ideally, I'd like to see if there are any additional/less files in either copy of the folder and then check to see if the individual files themselves have any differences.
Answer: diff only works with local files. You might use scp or rsync to copy the files to a local directory and compare it with diff, or you can use something like sshfs to mount a remote directory to a local one and compare it with the second one.
For a single file, you can use ssh and diff:
ssh user@machine cat remote-file | diff - local.file

Comment: Is there no ssh equivalent of diff? This would work... but it seems to me that someone else would have wanted the same thing, and hopefully done it. :P Thanks, though!
Answer: To see if there are any additional/less files in either copy of the folder
diff -y <(ssh user@remote_server 'ls -1aR /remote_folder/') <(ls -1aR /local_folder/)

Answer: An alternative to find which files differ is to use rsync, as described in https://serverfault.com/a/16665/317052. Use
rsync -anicu  . user@remote_host:directory/

Using 'diff' command over ssh


Why can't concave lenses be used as magnifying glasses?

Question: I see why convex lenses work, but why can't concave lenses work? The light from an object diverges, making it wider, so technically that should make the object bigger, shouldn't it? Why isn't this the case?
My thinking:
Comment: if that's true, then convex lenses would make objects smaller, which is not the case.
Comment: A glass (index of refraction 1.5) concave lens DOES magnify, in a medium of carbon disulfide (liquid with index of refraction 1.6).   Not in air, though.
Comment: @AccidentalFourierTransform I know that, but my question is why convex lenses won't work.
Comment: @Whit3rd *Why* not in air though?
Comment: @AdityaRadhakrishnan because $n_\mathrm{air}=1$
Comment: Convex lenses DO work, but do not magnify.  The formula for magnification comes out to less than 1x for a thin lens which is concave, if it has higher index of refraction than the medium of light transmission (usually air).
Answer: In your image it is not clear how you actually end up with a "big image". It is not enough to take into account just one light ray per point on the object.
You also need to consider how we actually see something, because if you think of it, at any moment there is light hitting our eye that comes from all kinds of directions and all kind of objects. However only a small part of it is actually used to make up the image we see.
You need to distinguish between virtual images and real images.
Real images are formed if all (or at least many) light rays coming from one point of the object are focused into one point on the viewer side. In that case you can for instance put a screen/paper on the viewer side on which an image gets projected. This is for instance the case in projectors or cameras.
In the case of Virtual images, the light rays diverge on the viewer side, so rays coming from one point of the object are  not focused into a single point on the viewer side anywhere. Therefore one cannot have a projection directly onto a screen. However all the rays from one point of the object appear on the viewer side as if they are coming from a single point (if there was no lens). The eye re-focuses all these rays and produces a real image inside the eye, in the same way as it would do when looking at a real object the size/distance of the virtual image.
Let's look at the four combinations of virtual/real convex/concave lenses for a single lens:
Convex, real image
If the object is located outside the focal length of the lens, a real (reversed) image is formed on the viewer side. This is effectively what you have in case of cameras, though they have somewhat more complicated optical system, since for instance they need to keep the distance from the lens to the film/sensor/screen constant, independent on how far away the object is. If you take a magnifying glass and look at distant object through it you should also get this effect. But note, that in that case your eye is not where the image is formed but further away (to the right in the image below).

Convex, virtual image
If the object is within the focal length of the lens a virtual image is formed. Light rays on the observer side are diverging but appear to come from a point corresponding to a larger upright (virtual) object. This is the case for the magnifying glass when used to magnify things.

Concave, virtual image
Independent on whether the object is inside or outside the focal length, these lenses always produce a virtual image that is smaller than the original.


Friend borrowed gaming keyboard to use on severely virus infected pc. danger to keyboard?

Question: is it possible for my keyboard, a Logitech G910 Orion Spark to get infected with a virus or a keylogger after a friend used it to type in his log in password? his laptop's built in keyboard wasnt working so he used mine merely to type in his password then he unplugged it (he only wanted to watch some youtube vids and only needed his mouse for that). my question is, since this is a mechanical keyboard with on board memory and macro capabilities, is it possible that it got infected in that short time frame? what are the odds of that? shouldnt the potential exploit have to be specifically coded to infect this specific product? if its possible to infect, how does one check and by extension how does one remove the potential exploit? i havent seen any signs, im just paranoid about stuff like this and wish to make sure.
Comment: I suspect not - there's more detail in what I would think was a duplicate: http://security.stackexchange.com/questions/39437/can-i-use-the-same-keyboard-on-both-my-infected-and-non-infected-computers
Comment: i saw this post, but i was wondering if the fact that my keyboard has on board memory and is capable of storing macros makes a difference so i decided to make a fresh thread
Answer: In fact, this is possible and Logitech peripherals have been used to attack machines, or to move malware from one host to another. Time doesn't really matter, because an infected PC can flash a hardware device in seconds (probably less).
Though I think it is highly unlikely you have been infected, for two reasons:

This type of expolit has not been seen on mass scale (yet) and has primarily been a topic of studies.
In addition to that, the malware must have been on the PC in the first place, and should have been capable of infecting you keyboard without any firmware corruption. This requires skills and a highly sophisticated piece of malware.

From what I gather, I don not think you have anything to worry about.
Update:
Like you said, a keyboard firmware will likely whipe the ROM.
Comment: i updated the firmware of my keyboard right after i connected it back to my own pc which i know is clean in the hopes that i could overwrite whatever potential changes were made to my keyboard's firmware. was that the right move? or didn't it even matter. anyhow, basically you are saying that the chances of my device getting infected is slim to none? Thanks for the reply btw, really appreciated.
Comment: @BlueWreck As a reference, I'd suggest the original paper https://www.usenix.org/system/files/conference/woot14/woot14-maskiewicz.pdf
Comment: when you say "a keyboard firmware will likely whipe the ROM." you mean the firmware update would likely remove whatever the infected pc could have potentially changed?
Answer: It is highly unlikely, and yes it would have to be tailored to the device. I'd like to point you to Karsten Nohl's BadUSB attack, the code for which has been public for almost 2 years now. The bad news is; you can't really reliably detect it. The good news, because it's so obscure it's only doable for governments and large companies to build malware for it. So the chance is not quite zero, but not enough to worry about.
Comment: i see. thanks for the reply. would a firmware update of my device potentially overwrite whatever changes/piece of code that could potentially have been injected? the laptop was something he hasnt used for over 2 years(almost everything should be out of date). (his current one went in for repairs and he wanted to watch some vids so he pulled out the old laptop)


Can I safely delete items in my "downloaded apps" folder?

Question: I want to free up space on my phone and was wondering if I can delete items in my "downloaded apps" folder.
  I know on my computer there is a difference between the downloaded file and the installed application and that once the application is installed the downloaded file can be deleted.  But I wasn't sure about my phone.
Comment: What is this "downloaded apps" folder? Where do you see this name?
Answer: Direct answer: Yes you can safely delete the apk you download once it is installed.
Developed answer: Any apk file you download goes to the external storage (either external sdcard or fuse-mounted internal storage that appears as external storage). Installing an apk is just a matter of copying it to internal storage (inside a folder within /data partition). so once installed, the apk becomes redundant, and it is safely to remove the one you downloaded.
Answer: If the folder you are refering has the apks of the apps you have downloaded then they can be deleted since they are not requied for the app to function.
Answer: When I attempt a delete of a file in the downloaded apps folder on 5 June 2017 on my Galaxy Prevail, a box appears advising that the app will be uninstalled.


How do you work with SQL Server CE and SQL Server 2008 Express?

Question: I have installed:

Visual C# 2008 Express
Visual Web Developer 2008 Express
Visual Studio 2008
SQL Server 2008 Express
SQL Server Management Studio

In Visual C# 2008 Express, I can "Add Item" and create a "Local Database" (.sdf file) or a "Service Based Database" (.mdf file).
Visual Studio 2008 is the same as Visual C# 2008 for applications but in Websites, the only way I can create .sdf or .mdf files is via the Database Explorer.
In Visual Web Developer 2008 Express, however, I can "Add Item" and ONLY create a "SQL Server Database" (.mdf file). Even the Database Explorer doesn't offer to create a SQL CE database.
Questions:

why the discrepency between the applications, is this normal or did something go wrong with my installations?
I never "installed SQL CE", where did it come from and how is it that I am able to create .sdf file?
How do you work with these in projects on a day to day basis, do you use Visual Studio to edit the databases or do you use SQL Server Management Studio?
Answer: I believe only Professional and above may create MSSQL CE databases.
SQL CE is installed with 2008 studio, I was surprised to see it myself and didn't see an option to exclude it.
Personally I use VS 2008 to add items to my project databases.  Since it's open anyway I just use it.  It provides most of the same functionality as Management Studio.  If I am doing separate database work, I usually do it in Management studio.
The CE databases are pretty useless.  They have a limited sub-set of types and functions.  They do not support views or stored procedures.  Basically they only store tables; I haven't attempted to create foreign keys in them.
There is no way to rename tables or columns.  You must create a new table.
Once you create your database it must be manually added to your project.
You cannot directly create a LINQ to SQL class in VS2008 on a CE database.  You need to use the command line tool sqlmetal (called from .NET console) to create the class for you.
I've had issues where the Class created for a CE database didn't work like a class built for a regular SQL database.  Because of this I abandoned using a CE database all together.
It would be nice if there was a reliable way to use Linq to SQL on SQLite databases. SQLite is a great self-contained database not requiring any type of external engine.
Sorry I don't have any performance statistics for an SQL CE database.
I hope this is somewhat helpful.
Brett
Comment: SQL Server CE 4.0 does support multithreading and is designed to be deployed with a WebApp into IIS.  http://blogs.msdn.com/b/sqlservercompact/archive/2010/07/07/introducing-sql-server-compact-4-0-the-next-gen-embedded-database-from-microsoft.aspx
Comment: Can you provide a citation for being unable to change table/column names in SQL CE? It looks like the ALTER TABLE command exists... ( http://msdn.microsoft.com/en-us/library/ms174123.aspx )
Comment: WRONG. SQL CE simply isn't supported by web sites. In fact, CE will explicitly prevent itself from being loaded by something running under IIS.
Answer: Ok registered now and not sure why got a -1 vote on previous answer but will expand.
Web Developer Express 2008 Does not create or work with Sql Server CE simply because SQL Server CE is not designed to work on the Web Server.
When you load c# express or vb express. sql server express 2008 is offered to be installed.  SQL CE isn't installed. if you go and add a data source the two I know will be there, Microsoft SQL Server Compact 3.5 (.NET Framework Data Provider for Microsoft SQL Server Compact 3.5)and Microsoft SQL Server Database File (SqlClient), the access client may be there also.
It should be noted with a default Express setup that if you choose to use the data provider for sql server compact it will fail even though it is an option. you would have to download sql server ce separately to create sdf databases.
Also Express versions are targeted to a different audience and doesn't have the same ui setup as the main vs sku's have. For example  Web express in database setup doesn't even offer the choice to use sql server ce.  while in VS it is a choice from the data menu mainly because VS supports more than just web developer.
Now you said you loaded VS 2008 (didn't say what version but doesn't matter since this affects standard and above)
The default install for vs 2008 will install Sql server ce (and as previous answer stated 3.1 was with rtm, 3.5 was with sp1).  you can turn it off in advance options.
One concern I have is that you mention that you can't create a database in vs on web projects. which template are you using.  You should be able to create server based database Items in add item and both local and server database objects in the data tab.
so in Summery.
on client based express skus and client based projects you should be able to create a local or server based database from add item and from the data tab.
Since sql CE is not officially supported on the Web Server. on the web skus in add Item you should only have access to create a server based database.  on express since it is a dedicated sku CE isn't an option in either the data tab or the add item.  on vs you can create a CE database from the Data tab. and you should have access to create a server database in add item.
sql server management studio doesn't care where the source is. so it will work with all and create the database.
I use all the options listed just depending on what or where I am at the time.  as was mentioned CE on the desktop is primarily a cache database perfect for offline database support.  but does have its limitations and in addition really needs better integration. once I am created or working with a database in support I primarily use management studio.
Comment: A lot more verbose but not much more useful, for a simple question.
Answer: This is normal.  The database types supported by the Visual Studio designer differ by edition.  Note that any version of Visual Studio can write and use code that connects to any of those databases.  It's just that the visual "wizard" tools included with the IDE that walk you through it are different for each edition.
SQL CE is the Compact Edition of sql server.  It's intended for use on portable devices like smart phones or as an Access replacement for a local data store in desktop apps.  It's very portable: only 2 dlls that clock in at less than 1Mb of disk space, and was probably included with at least one of your Visual Studio packages, probably all of them.
I normally do all my database work from Management Studio, but that's a personal preference.
Comment: No, the issue is that CE doesn't run under web sites so it makes no sense to offer it in the "Web Developer" edition.
Comment: CE certainaly _can_ run in a web site.  It's probably not a good idea to use it in that scenario, though.
Answer: The key point in why you can't access CE from Web express is that CE is not supported on the web server.
Douglas
Comment: I don't know why you had a down vote. CE explicitly blocks IIS from loading it into memory.
Answer: The discrepancy is odd, but since SQL CE is a plugged-in item, it may well be that the team didn't test every possible scenario and some of the applications simply didn't get the info they needed to know that it's there.  I'm not saying that anything went wrong - it may simply be a scenario that the SQL CE team never tested.
SQL CE was installed with Studio (can't recall offhand, but I think 3.1 shipped with the RTM and 3.5 shipped with SP1).
I always use Management Studio for making database modifications (except those done directly in code).
Comment: This was intentional. Web sites can't use SQL Server CE by design.
Comment: I'm going to call BS on that - you have no idea what you're talking about.  SQL CE 3.5 is fully desktop compatible, with a desktop client, including 64-bit support.  It doesn't "know" if a web site is connecting to it and here's no "design" that precludes using it for a web site.


Can there be a compound which stops the pesticide from entering into the fruit or vegetable?

Question: Can there be a compound which stops the pesticide from entering into the fruit or vegetable? For example, a solution which is sprayed before pesticides and somehow blocks pesticides from entering into the fruit?
Comment: You mean a substance which itself stays completely on the surface, does not get washed off and pollutes the surroundings, is totally harmless to birds and insects, and completely decays into water and carbon dioxide within a few weeks?
Answer: In addition to all the qualities @Karl stated (harmless, edible, overspray decomposes, etc.), such a coating would also need to stretch as the produce grows. Such a protective covering might even obviate the need for pesticides, if it were to be created.
That said, there are edible wax and protein coatings to preserve produce after it's picked. Unfortunately, these are applied after pesticides may have been sprayed on the food, so one hopes that the produce is washed before spraying seals in toxins.