Minecraft how to detect when a player accesses an anvil?

Question: How would I detect when a player interacts with an anvil? And I don't mean by repairing, I mean opening the anvil interface. How would I also detect when a player interacts with an enchantment table? The only way I can think of is wait till Mojang adds those statistics. Also, is there anyway to stop the interface coming up for crafting tables? the only way I can think to do it is to test for if it has been interacted with, and then immediately  replace it with another crafting table. Any help would be appreciated.
Comment: I don't think you can do this without mods right now.
Answer: First two questions aren't possible as far as I know. There's not really a good way to detect if a player right clicks in general; whether it's a specific block would be even harder to detect.

The third question is possible though, as there's a stat.craftingTableInteraction scoreboard objective type.
First, create the objective to track people opening a crafting table:
/scoreboard objectives add openedTable stat.craftingTableInteraction

Delete the crafting table:
/setblock X Y Z air

Then wait a tick for the interface to close, and replace the crafting table:
/setblock X Y Z crafting_table

This should work, but keep in mind that if the player is lagging or has a modded client, they may still be able to craft; don't rely on it completely to stop people from crafting.
Comment: Would it be possible to just replace the crafting table with another crafting table? Setting air and then a crafting table there would probably be a few seconds where the player could see that interface.
Comment: @thezi3 Not as far as I can tell. You can remove it in one tick and replace it in the next to have it pretty much instant, but replacing it with another crafting table straight away does nothing (it's still the same block, nothing has changed).


Can we construct fully homomorphic encryption scheme based on non-circuit approach?

Question: At present, all FHE scheme are be constructed based on circuit approach. Can we construct fully homomorphic encryption scheme based on non-circuit approach?  Is Polly cracker non-circuit approach ?
Comment: Could you explain (probably in an edit to your question) exactly what the "circuit approach" is?
Answer:
Is Polly cracker non-circuit approach?

Polly Cracker is non-circuit.

Can we construct fully homomorphic encryption scheme based on non-circuit approach?

The best info for this I could find comes from a recent paper proposing a non-circuit approach due to Xiao, et al..
They identify a number of non-circuit systems, but go on to say that "they all either have been broken or lack conclusive security evidence."
They then propose a symmetric system which reduces to the problem of factoring.
So it seems that the answer is yes, one can be constructed. It is still an active area of research, however, and I personally wouldn't use the proposed systems yet.
Now, what I am exactly not quite sure of is what non-circuit means? In the paper I reference, they state:

The main works on homomorphic encryption algorithms are circuit based. They develop the encryption schemes and computation algorithms considering a single bit plaintext. All operations on various operand types can then be achieved by constructing the corresponding circuits.

So is a circuit approach simply that the cryto algorithms assume a single bit plaintext? If that is the case, then there are many, many more FHE systems which are "non-circuit". In fact, the BGV system does not require single bit plaintexts. So perhaps I am missing something in the circuit vs non-circuit discussion.
Comment: Xiao' paper I read before two weeks, so this problem produce in my mind. Gentry's definition of FHE isnot same as in xiao's paper. The defination in Xiao's paper is homomorphic rather than fully homomorphic. Even though Polly Cracker is non-circuit, this scheme isnot fully homomorphic encryption.
Comment: @ZhigangChen, I'm not sure I follow. Could you explain what Gentry's definition of FHE is and the difference with Xiao's? Do you mean that Xiao's system does not require bootstrapping, and other tricks that Gentry's system does require?
Comment: Homomorphic scheme in Xiao's paper can only compute polynomial on encrypted data rather than arbitary functions, for example, loop, Xiao's scheme cannot compute. Fully homomorphic scheme can compute arbitary functions(include loop), it is because circuit model is used in FHE. Any computation in FHE first express circuit to compute.
Comment: @mikeazo, circuit and non circuit is nothing but black box and non black box way of solving , see my answer below
Comment: @ZhigangChen thanks a lot for clarifying the difference, i almost missed it !
Answer: In cryptographic literature ,a black-box construction is one that uses only the input/output behavior of its components. By contrast, a non-black-box construction relies on the code of its components ( i.e circuit representation gate by gate etc). Non circuit based approach is usually called "black box" approach , a recent paper , although not directly on homomorphic encryption but very close concept can be found here . (Note: I am yet to read it completely, but this is very fascinating paper on black box and non black box approaches ) . If interested you can read "instance hiding" schemes, which are usually on blackbox approaches.
Comment: It's hard for me to tell (the original question is not very clearly written), but my guess is that I don't think this is what the original question-asker meant by "circuit approach".
Answer: Yes There was recently a breakthrough FHE and it used p-adic ring homomorphism. the paper was published on nov 10 2012. and the algorithm is LITERALLY quasi-linear time without any "lambda" factor in the keys and NO noise in the ciphertext. it seems to be a very big breakthorugh and i don't know why no one has paid attention yet but me :P . here is a link to that paper, its VERY mind boggling and amazing. If you dont know p-adic numebrs, then take a look at the abstract and conclusion; and if the algorithm really works as claimed then it will throw IBM and Microsoft decades behind. here is the link http://www.ijtpc.org/volume1/JTPC1386.pdf
I hope you enjoy reading about this breakthrough. btw, the homomorphic part of the encryption "LITERALLY" goes like for addition E(m1)*E(m2) = E(m1+m2) and multiplication is like
E(m1)^m2 = E(m1*m2) ; Algorithm says it used p-adic ring exp to obtain this effect. Its way different and much advanced than Gentry's scheme.
Comment: I posted this on your other post, but what you are describing is not fully homomorphic. $m_2$ is not encrypted. You can not get the multiplication of two encrypted values (at least I'm assuming not, I haven't read the paper). Furthermore, I don't see how this particular answer goes along with the question of non-circuit based FHE.
Comment: I count three or four red flags just in the abstract and keywords of this paper. Also, what is the security reduction? What evidence is there that the underlying problem is computationally hard?
Comment: "ZK111 is perhaps the only known public-key encryption
algorithm which is also Information Theoretic Secure." My bullshit detector is going crazy.


iOS Inputs in UITableViewCell

Question: I have followed this tutorial for building a text field form inside a table and i've managed to do it but in the tutorial he just uses a single type for the fields. I want some fields to have dropdowns and i'll also add other fields.
I'm not sure of the best way to do this, i'm guessing the fields need to be in an array to make it a lot easier to manage. I was thinking of the code below, the structs are just generic for now.
struct DropdownInput {
    let name: String
    let placeholder: String
    let defaultValue: String
    let values: [String]
}

struct TextInput {
    let name: String
    let placeholder: String
    let defaultValue: String
}

var formFields: [Any] = [
    TextInput(name: "test1", placeholder: "Some value", defaultValue: ""),
    DropdownInput(name: "test2", placeholder: "Some value", defaultValue: "", values: ["Test1","TEST2","Test3"]),
]

Edit: My code is working but I think it's not unpacking the formField object properly. It's saying value of type Any has no member name, how can I access the values?
    if self.formFields[indexPath.row] is TextInput {
        if let fieldValues: Any = self.formFields[indexPath.row] as? TextInput {
            if let cell = tableView.dequeueReusableCellWithIdentifier("cellTextField") as? TextInputTableViewCell {
                print(fieldValues.name)
                return cell
            }
        }
    }

Comment: Which error did you get? Also you can reduce code by using `if let textInput = formFields[index] as? TextInput`
Comment: make sure you have attached TextInputTableViewCell class for both cells.
Comment: and I'd suggest to use `dequeueReusableCellWithIdentifier:forIndexPath` so that you'll be sure you registered cell's class/nib
Answer: Answering your question that "any has no member name" - just remove Any and use
if let fieldValues = formFields[indexPath.row] as? TextInput {
   print(fieldValues.name)
}

Answer: You can make it a little simple if you have two different cells;
struct TextInput {
    let cellIdentifier: String
    let name: String
    let placeholder: String
    let defaultValue: String
    let values: [String]
}

var formFields: [TextInput] = [
    TextInput(cellIdentifier: "cellTextField", name: "test1", placeholder: "Some value", defaultValue: "", values: []),
    TextInput(cellIdentifier: "cellDropdownTextField", name: "test2", placeholder: "Some value", defaultValue: "", values: ["Test1","TEST2","Test3"]),
]

and then;
let txtInput:TextInput = self.formFields[indexPath.row]; //It is not optional, so no if condition.
let cell = tableView.dequeueReusableCellWithIdentifier(txtInput.cellIdentifier, forIndexPath: indexPath) as! UITableViewCell; //It must return cell, if the cell is registered so no if condition here too.

return cell;

iOS Inputs in UITableViewCell


How are neural networks used when the number of inputs could be variable?

Question: All the examples I have seen of neural networks are for a fixed set of inputs which works well for images and fixed length data.  How do you deal with variable length data such sentences, queries or source code?  Is there a way to encode variable length data into fixed length inputs and still get the generalization properties of neural networks?
Comment: I'm voting to close this question because it is not about programming as defined in the [help] but about ML theory and/or methodology - please see the intro and NOTE in https://stackoverflow.com/tags/machine-learning/info
Answer: I have been there, and I faced this problem.
The ANN was made for fixed feature vector length, and so are many other classifiers such as KNN, SVM, Bayesian, etc.
 i.e. the input layer should be well defined and not varied, this is a design problem.
However, some researchers opt for adding zeros to fill the missing gap, I personally think that this is not a good solution because those zeros (unreal values) will affect the weights that the net will converge to. in addition there might be a real signal ending with zeros.
ANN is not the only classifier, there are more and even better such as the random forest. this classifier is considered the best among researchers, it uses a small number of random features, creating hundreds of decision trees using bootstrapping an bagging, this might work well, the number of the chosen  features normally the sqrt of the feature vector size. those features are random. each decision tree converges to a solution, using majority rules the most likely class will chosen then.
Another solution is to use the dynamic time warping DTW, or even better to use Hidden Markov models HMM.
Another solution is the interpolation, interpolate (compensate for missing values along the small signal) all the small signals to be with the same size as the max signal, interpolation methods include and not limited to averaging, B-spline, cubic.....
Another solution is to use feature extraction method to use the best features (the most distinctive), this time make them fixed size, those method include PCA, LDA, etc.
another solution is to use feature selection (normally after feature extraction) an easy way to select the best features that give the best accuracy.
that's all for now, if non of those worked for you, please contact me.
Answer: You would usually extract features from the data and feed those to the network. It is not advisable to take just some data and feed it to net. In practice, pre-processing and choosing the right features will decide over your success and the performance of the neural net. Unfortunately, IMHO it takes experience to develop a sense for that and it's nothing one can learn from a book.
Summing up: "Garbage in, garbage out"
Comment: What about the case where you want the neural network to extract the features and feed it to another network for classification / interpretation.  Or you want the network to learn a grammar from a set of examples.  In both these cases the network would need to process variable length data sets.
Comment: There are times when you want a bidirectional associative memory and the size of the items to associate are different. (name of person, picture of person)
Answer: Some problems could be solved by a recurrent neural network.
For example, it is good for calculating parity over a sequence of inputs.
The recurrent neural network for calculating parity would have just one input feature.
The bits could be fed into it over time. Its output is also fed back to the hidden layer.
That allows to learn the parity with just two hidden units.
A normal feed-forward two-layer neural network would require 2**sequence_length hidden units to represent the parity. This limitation holds for any architecture with just 2 layers (e.g., SVM).
Comment: It is more similar to a neural network with some output fed to the next input. Unimportant history will be forgotten over time.
Comment: Is this similar to a hidden markov model only using neural networks?
Answer: I guess one way to do it is to add a temporal component to the input (recurrent neural net) and stream the input to the net a chunk at a time (basically creating the neural network equivalent of a lexer and parser) this would allow the input to be quite large but would have the disadvantage that there would not necessarily be a stop symbol to seperate different sequences of input from each other (the equivalent of a period in sentances)
Answer: To use a neural net on images of different sizes, the images themselves are often cropped and up or down scaled to better fit the input of the network. I know that doesn't really answer your question but perhaps something similar would be possible with other types of input, using some sort of transformation function on the input?
Answer: i'm not entirely sure, but I'd say, use the maximum number of inputs (e.g. for words, lets say no word will be longer than 45 characters (longest word found in a dictionary according to wikipedia), and if a shorter word is encountered, set the other inputs to a whitespace character.
Or with binary data, set it to 0. the only problem with this approach is if an input filled with whitespace characters/zeros/whatever collides with a valid full length input (not so much a problem with words as it is with numbers).


When did aircraft carriers eclipse battleships as the "King of the seas"?

Question: During the 19th century and into the early 20th century, battleships were the Kings of the Sea, and every naval power of note had at least one. When did they lose this title to the aircraft carrier, and was it a particular battle, event, or was it a more gradual series of events that lead to the changeover in naval strategy?
Answer: I would date the transition to aircraft carrier domination to the Battle of Midway, in June 1942.
The Japanese fought an old style battle in four ship waves. In the first wave as a carrier task force, plus supporting cruisers and battleships, whose main task was to soften up Midway by air bombardment, and then screen the rest of the Japanese fleet.
In the second wave was a supporting force of four cruisers. In the third wave were the transports, escorted mainly by battleships and cruisers. And the fourth wave contained three of Japan's largest battleships, which was supposed to deliver the coup de grace to the American fleet, after it presumably rushed to save Midway.
After the destruction wrought at Pearl Harbor, the Americans had only one "wave," a carrier task force of three aircraft carriers and supporting cruisers, roughly equivalent in strength to Japan's first wave alone.
The battle degenerated into an air to ship battle, along lines similar to those of Coral Sea, fought a month earlier. With their greater focus, the Americans sank all four Japanese aircraft carriers, while the Japanese, who had been concentrating on Midway at the expense of watching out for American carriers, sank only one. (Two, if you count the temporary destruction of Midway as a "carrier.") The surviving American carriers then stayed out of sea range of the Japanese battleships, but the Japanese didn't dare to invade Midway while the Americans had carrier aircraft within air range.
This battle proved the dominance of carrier based aircraft over ships. Carriers had proven their worth at Coral Sea, but it was considered a "fluke" because no battleships had been involved. At Midway, Japanese battleships were present and had their "chance," but basically chose not to fight.
Comment: Frankly, I'd argue for Pearl Harbor, as an entire US fleet was sunk using nothing but carrier-based air power without being able to fire back so much as a shot at any of the attacking ships. Anybody with half a brain should have seen the writing on the wall at that point. This is a very good argument though.
Comment: Pearl Harbor was considered a "fluke" or at least "unrepresentative," because it was a surprise attack. Midway was a "stand up" fight.
Comment: @T.E.D.: Why not Taranto, a year earlier than Pearl: https://en.wikipedia.org/wiki/Battle_of_Taranto
Comment: Midway did not prove anything for the battleship-carrier theoretical opposition. It was a pure carrier opposition, and the Japanese losses pushed them to abandonn the fight. At Guadalcanal, there was no opposition as well but the American land-based aviation prove to be an asset against the Japanese surface ship
Comment: @TomAu I disagree: Midway prove the usefulness of carriers (and the battle of Coral sea did before), not that battleships were "eclipsed". The decline of battleships started after Guadalcanal massive battles, or maybe even later in 1944 with the defeat of Japanese and German surface fleets in the Philippines and Arctic sea
Comment: @totalMongot Or even sinking of the Bismark it beat other battleships but air power crippled it. It showed that Battleships were just targets. Also Prince Of Wales and Repluse near Singapore albeit land based air
Comment: @mmmmmm yes but the strategic situation of the Bismarck was unfair for Bismarck. Plus destroyers and heavy battleships (Renown if I recall) sank the Bismarck in the end, even if fatal damages were made by airplanes
Answer: Sea power is not directly about which ship type can beat up which other ship type; it's a matter of being able to run one's merchant ships in an area and preventing the other side from running merchant ships.
In WWII, it was difficult for surface ships to protect a convoy from air attack, as we can see from the 1942 attempts to relieve the siege of Malta.  Moreover, naval powers were hesitant to risk battleships in the face of enemy air power, particularly after the British lost a modern battleship and older battlecruiser to Japanese air attack off Malaya shortly after Pearl Harbor.
The questions, then, were whether aircraft carriers could defend themselves against battleship attack and whether aircraft carriers could protect shipping against battleships.
In WWII, carriers were generally able to not be sunk by battleships or other surface ships, unless badly handled like HMS Glorious off Norway.  Their aircraft gave them warning of enemy forces, and their generally high speed enabled them to avoid combat.  Therefore, they could stay in an area despite enemy battleship forces.  (This was not
always the case; in the 1930s, when carrier aircraft had much less range, US battleships "sank" US carriers a few times in the annual Fleet Problems.)
Their ability to defend shipping against battleships was a bit less certain.  Normally, heavy air attacks would deter battleships from proceeding.  After all, there weren't many battleships around, and they were expensive.  If the enemy was determined to force his way through, some surface ships would likely make it through.  This was shown by RN cruisers and destroyers around Crete and the Japanese Center Force in the Battle of Leyte Gulf, both of which carried out their missions despite serious losses.  No naval power could afford to lose battleships with each mission, unless the enemy missions were extremely critical (the Battle of Leyte Gulf was an attempt to stop the first US landings in the Philippines).
Comment: It wasn't purely about being able to move merchant ships around but also being able move naval firepower freely around.  Naval power that could help with amphibious landings and provide a mobile airfield for support.
Answer: Through the course of World War 2; in September 1939 battleships were still considered more important than aircraft carriers, and by VJ Day carriers were considered utterly decisive at sea.
This process took a good few steps, however, and really examining it in detail could take an entire book.
You also need to consider the application of carrier air power to two main problems:
1) the decisive battle
2) the guerre de course, or convoy war.
So, first let's look at decisive battle. At the beginning of WW2, it was by no means taken as read that unsupported aircraft could sink a battleship; so while a carrier could do extremely well at finding a battleship, and keep a safe distance from her, sinking her was another matter. And the carrier could hardly replace the battleship if a carrier couldn't even sink a battleship.
As a result, any would-be naval power had to have battleships in order to counter enemy battleships, whereas those who expected their navy to operate in range of land-based air support (Italian, German) did not need aircraft carriers.
This assumption had to be overcome by experience, and there were several battles which made that example, and then rubbed it in the noses of the gun-deck admirals.
At Taranto in November 1940, the Royal Navy sank an Italian battleship in harbour and damaged two more, for the loss of two obsolescent torpedo bombers; so battleships were proven to be vulnerable to carriers when unable to manoeuvre freely.
In the chase of the Bismarck, the carrier aircraft did not sink Bismarck - however, they did damage her rudder, enabling her to be caught and destroyed by battleships.
Then we have the fate of Force Z - a surface-force only, consisting of a battleship, a battlecruiser and a few destroyers sunk by Japanese air attack. These were not carrier aircraft - the Japanese carrier force were somewhat busy at Pearl Harbor - but the crucial difference with Force Z, which differentiates it from Taranto and Pearl Harbor, is that Force Z was sunk while under sail, showing that any naval force which went into reach of enemy aircraft without its own air cover would be sunk.
Having already mentioned the parallel, I would be remiss to not cover Pearl Harbor - this is essentially Taranto writ large. It showed that if your enemy has a sufficiently powerful carrier arm, your fleet is not safe in harbour anywhere, not even across an ocean.
Then at Midway the combat between the American and Japanese carriers was decisive, without the Japanese battleships becoming engaged.
So, enough about decisive battle - what about the guerre de course, conducted primarily in WW2 by German U-boats?
Well, protecting a convoy against U-boats was helped hugely by air cover. Spotting the submarines in the first place, guiding in escorts to kill them or killing them directly, routing convoys around them (and providing excuses to use ULTRA intercepts to route convoys around them), forcing submarines to submerge and lose a chance to make an attack...the uses of aircraft in the Battle of the Atlantic were many and varied.
However, at the start of the war there was a gap in the mid-Atlantic where land-based aircraft could not reach a convoy to protect it. Some desperate measures were used to help close the gap, including CAM ships (Catapult Aircraft Merchantmen which carried a single Hurricane on a catapult; this could be launched once, and at the end of the flight the pilot had to ditch the plane and bail out), the slightly more capable MACs (Merchant Aircraft Carrier) which carried about 80% of a normal cargo and had three or four aircraft embarked which could be recovered after a flight.
These were stop gap solutions - as the war went on, they were gradually replaced with escort carriers, which were generally akin to MACs in that they were based on merchant hulls, with the difference that they were full conversions no longer carrying any cargo and could carry perhaps 20 aircraft - they were still too slow to operate with a fleet.
There were many aspects to the outcome of the Battle of the Atlantic, but unlike decisive battle where the battleship admirals resisted fiercely the supplanting of their beloved big-gun ships, the usefulness of air power to this aspect of naval warfare was little doubted, and the frantic attempts to close the Air Gap in the Atlantic show this quite clearly.
Comment: +1 although answer would benefit from more references.
Comment: Wxcellent answer.
Answer: Battleships became obsolete with the rise of air power; this was clear to General Billy Mitchell at the end of WW I.

A 2,000 lb. bomb "near-miss" severely damages Ostfriesland at the stern hull plates (1921)
A series of tests were conducted between 1921 and 1925 which conclusively showed that battleships could be severely damaged or sunk by means of aerial bombing.  It took time, and repetition, for the lessons to "sink in", but they did, and this lead to the creation of the air craft carriers which played such a prominent role in WW II.
The balance is found in "cost to build and operate" vs "cost to destroy"; air power is cheaper and more flexible than the battle ship.  Note that coastal defenses in the form coastal artillery were also rendered obsolete by air power.
Comment: True, and +1 for pointing this out, but it's only true in hindsight. At the beginning of WWII, the battleship was still considered invulnerable to air power.
Comment: @Peter Diehr: Two flaws there: 1/ the tests conducted on old ships only prove air power could sink passive battleships. It proved armor was not invulnerable, not that the battleship could not defend itself with manoeuver and AA Artillery. 2/ battleships are flexible just as battleships: battleships are used against other ships, as land support or land attack. Air power by the time was used as well
Answer: The Japanese sank the Royal Navies greatest and one of their most sophisticated Battle Ships HMS Prince of Wales and its older escort Cruiser HMS Repulse off the coast of Malaysia on 10th December 1941 using land based bombers and torpedo planes. The British ships had no air cover and were sunk relatively easily. These were the first ever capital ships sank purely using aircraft and the Allies realised a handful of torpedo planes sinking the Prince of Wales meant the era of the Battleship was over. Air power was everything and the Carrier was King.
https://en.wikipedia.org/wiki/Sinking_of_Prince_of_Wales_and_Repulse
See Z-Force mentioned in the answer above, Z-Force was HMS Prince of Wales and its escorts.
Comment: To some extent this is now slightly less the case than it was. In the Falklands Campaign the Royal Navy accounted for a lot of Argentine aircraft with Sea Wolf and Sea Dart missiles. Problem in Dec 1941 was that every last aeroplane that Britain had was being used in the defence of Britain.
Answer: The question could be divided in two parts: First, when did they loose the title of King of The Sea to Aircraft Carrier, then when did the naval strategy change?
And of course, all of that should be considered in respect of each country's naval system.
Germany
The Germans aimed during WW1 to be challenger of the seas. They used battleships against UK's battleships and they failed. But aircraft carrier was a concept by the time.
During WW2, the Germans aimed to attack trade and challenge Allied escorts with battlecruisers and fast battleships. The Bismarck/Tirpitz were of them. When the Bismarck was sunk by the British, with great help of the Ark Royal carrier, the Germans ceased to consider battleships as King of the Sea. They still used them in their naval stategy, but with more caution in face of a carrier. Eventually the Tirpitz was sunk by land-based aircraft and the defeat ceased the German naval strategy.
UK:
The British had a strong prescience of the capacities of aircraft carriers. But they also had strong traditions, so they aligned both capabilities. The use of battleships in fight remains very prominent until the defeat of the Z force to massive land-based air attacks. This was the end of battleships as King of the Sea, because initally the Z Force was supposed to save Malaysia from the Japanese (please note that the Z Force was supposed to be supported by a carrier, but losses in the Mediteranean Sea hampered this strategy).
But the naval strategy continue to put an emphasis on both means, mainly because:

Battleships were still useful against German battlecruisers/battleships (see the Scharnorst)
Battleships still provided support to land attack
There was battleships in the inventory, so the British used them because they were available. On the contrary, they were carriers but losses of carrier did not help to use them all the time
Japanese navy was mainly fought by the Americans and not the British

Italy:
Italy mainly based its navy, the Regia Marina, on battleships.
The attack of Taranto reduced their availability. But the turning point was the battle of the Matapan, a fight during which one British aircraft carrier compensate the Italian advantage in naval gunnery.
Naval strategy changed: the Italians still used battleships (and heavy cruisers), but under the protection of land based air power. This reduced their ability to intercept with naval forces British convoys.
Overall, after Matapan the Italians did not consider the battleships as King of the Sea anymore.
USA:
Let's change the part of the world we're considering: The USA mainly fought other ships (except submarines) in the Pacific Ocean.
During thoses fights, battleships were involved in various tactical situations. The first major event, of course, is Pearl Harbour: by destroying or damaging most of battleships, this Japanese attack force the Americans to center their strategy on aircraft carriers.
BUT it does not mean battleships were diminished: the Americans mainly faced Japanese carriers with their own carriers so it did not mean anything during the battles of Coral sea and Midway.
Later however, the naval strategy changed progressively during Guadalcanal fights and later: the battleships were centered on the role of night fighting, while in the Center Pacific they escorted carriers that led the strikes on the Japanese fleet: this was a strategy change
Eventually, after the big surface battle of the Philippine sea, aircraft carriers had proven central but battlehsips were still useful and powerful, and the Americans had not yet won a major battle of carrier-based aircraft against battleships: this came in 1945 with the sinking of the Yamato: the King of the Ocean had fallen.
Japan:
Of course, the evolutions for Japan are linked to the ones for Americans. There were some differences of spirit, though, but overall the same events triggered the same changes. Only point: with the early loss of carriers the Japanese had to turn to a aircraft-carrier central strategy to a battleship strategy in 1944, that failed with the turning point mentionned above.
Answer: As other have said, the change became appreciated during WWII.
An important prerequisite for the change was the advent of aircraft engines in the 1000hp class, which meant that single-engine aircraft that could fit on carriers could also carry bombs and torpedoes powerful enough to be a serious danger to large warships.
Such engines started to come into service in the mid-1930s, which was only about one battleship building cycle before the outbreak of WWII. It's thus easy to see why the change wasn't appreciated until ships had been sunk.
Answer: The predecessor of the aircraft carriers were the seaplane carriers. UK was the first country that used in naval combat with great success (battle of Jutland). So was the success of that warship that UK improved them into an aircraft carrier. HMS Argus was the first aircraft used by UK in 1918.
Comment: Not sure this answers the question.
Comment: British seaplanes were present at the Battle of Jutland, true, but I'm not seeing any evidence that they were used for anything other than scouting (or that they were particularly effective at that).


How can I add a melting effect towards a specific part of my picture in GIMP?

Question: I want to make something horror-like, but the only thing that comes to mind is "Melting of skin". So I experimented with GIMP but couldn't find anything. What specifically I want it to look like, is this:
Comment: Hell-0 Michael! Can you show us what you've tried and edit your question to add some context and be more specific, and maybe even the file you've made tests on? Dripping blood, flesh, brains or whatever are all using similar techniques and tutorials. All I see in this animated gif is an hungry dyno but not much dripping! Maybe you should move the character in this animation a few steps forward for this to happen ;)
Answer: You won't find any "automatic" melting/dripping effects.
You need to learn to make your own by matching 2 or more pictures together, and using layers masks (or whatever it's called in Gimp.)
The trick to show skin as if it was peeled off or removed somehow is to use a picture with bones, and the original picture. You can also use different bones and stick them under the main subject, as long it biologically makes sense.
I don't know Gimp but you can use the same similar basic techniques in Photoshop or Gimp.

When you don't know how to draw something, you don't re-invent the
  wheel; you simply use 2 pictures and merge them together.

For example these 2 pictures:

Can become like this:
All I did was to put Britney's picture on a layer on top of the skeleton, and then I erased some parts of her face with different brush transparency, using a layer mask. And you can add red to show some tension or whatever fluid you want.

And if you want to add dripping stuff
You can use a bright color and trace roughly some lines and use overlay on that layer. It doesn't need to be perfect.
Then you duplicate that layer and move it slightly up/down and left/right, and add a saturation on it. It's an easy way to get a thick liquid effect with some shine!
You can add some dimension to the ripped skin by adding a line of a darker red as I did on the top of the mouth. That layer is simply in multiply. And then if you want even more realistic effect, you add very light shadow under these areas to give the impression the skin is at a higher level than the bone. And you can also add some lighter color on top of this area to add more light and add more dimension too. I didn't do any shadow or lightning effect in this example below.

You can use embossing and other colors
If you want some alien kind of dripping, you can use other blending modes and add some embossing to the "fluids", and simply change the colors.

You can add muscles or anything other parts and merge them too with layers masks and add shadows
Use layer blending modes, some layers with brush, and lot of layer masks and play with transparency.*

This is what was used.

If you wanted to make an animation with these effects, you'll need to make many of these images with different melting and dripping phases, and assemble them.
* I know the eyeball is not the same color. Her contact lenses fell off.
Comment: One could add a muskcle layer too ;)
Comment: @joojaa One could indeed! Pretty much anything can be added... metal and electronic parts, unborn twin! Not much limits, very fun.
Answer: The simpliest way would be to change the color of the place you want burned out. But make sure you do it step by step, so only change a little bit of color every frame.
I hope you do know how animations work in GIMP?


How do I enable multicast routing in Windows XP

Question: I have successfully set up a Windows XP machine as an IPv6 router using netsh, that is, it announces prefixes and forwards packets on two interfaces, as verified by pinging.
Now I'd like to forward multicast frames between both subnets; hosts on both sides are properly sending out multicast listener reports, so all it would take would be for the router to process these and start forwarding datagrams.
How can I enable IPv6 multicast routing between two interfaces?
Answer: To merely forward IPv6 multicast packets, you need to have Windows Vista/Server 2008 or later. Windows XP does not support this at all. (XP's IPv6 stack was very limited and is not recommended for production use.)
With the proper OS, you would enable IPv6 multicast forwarding with:
netsh interface ipv6 set global multicastforwarding=enable

or in PowerShell:
Set-NetIPv6Protocol -MulticastForwarding=Enabled

At this time, however, no version of Windows is capable of acting as a full IPv6 multicast router:

However, at the time of the publication of this book, there is no mechanism to update the IPv6 multicast forwarding table. Entries in the IPv6 multicast forwarding table allow the IPv6 protocol to determine how to forward incoming IPv6 multicast traffic. An IGMP routing protocol component for the Windows Server 2012, Windows Server 2008 R2, and Windows Server 2008 Routing and Remote Access service allows a computer to act as an IPv4-based multicast forwarding router. There is no corresponding routing protocol component for MLD that allows a Windows Server 2012, Windows Server 2008 R2, or Windows Server 2008–based computer to act as an IPv6-based multicast forwarding router.

This information taken from Understanding IPv6, Third Edition, pages 201-202.


I have 20 symptoms and need to do a hierarchical cluster analysis? Which method is appropriate?

Question: and thank you in advance for any suggestions. I have 20 binary symptoms (for example, anxiety yes/no, depression yes/no), and i have to do a cluster analysis for my research project in order to see which symptoms cluster together. However, i find this quite challenging, as i don't know which method of hierarchical cluster analysis i should use and what distance measure. Any help would be highly appreciated. Thank you!!
Answer: Any help would be highly appreciated Ok, I did a quick search on CrossValidated and found that there are several similar questions with excellent answers. This one shows hierarchical clustering is very well suited to binary data. Two step clustering is also mentioned . There are many similarity measures for binary data. See A Survey of Binary Similarity and Distance Measures for example. Both the answers linked to above contain plenty of additional links for further reading.
Kudos to the authors for providing much better answers than I could.
Best thing is to read around the topic and then start playing with various hierarchical clustering models and simialrity measures. There is a simple introduction to R's hclust algorithm here and another cross validated question here with R code included to get you going. I hope this helps
Comment: Thank you Martino, i have read quite a bit about it but it becomes more and more complicated. Thank you for your help anyways. All the best.


Earth's interior heat ratio between pressure and atomic decay

Question: What is our current understanding between the ratio of Earth's interior heat between the downward pressure and atomic decay?
Answer: There is no heat caused by pressure. Heat increases with depth, like pressure, so the two show a correlation, but this does not imply causality.
The two main sources of Earth's internal heat are radiogenic heat (as you said) and primordial heat, that is the kinetic energy turned into thermal energy during the accretion of the planet. There are also minor sources, like tidal heat caused by the Moon, and latent heat caused by crystallization of the liquid core.
The total heat budget of the Earth is pretty well constrained: we can just measure the heat flow coming out at the surface (in W/m$^2$) and multiply this by the Earth's area. The current estimate is ~47 TW (Davies & Davies, 2010). Getting ratios between sources, however, is more difficult, and rely mostly on modelling. See for instance the work of Dye (2012), who proposed a radiogenic heating of 15–41 TW, while other authors (referenced by Dye) proposed 12–30 TW of primordial ("fossil") heat. As you can see, the uncertainty is still quite high...


Can smoke from small fire cause wiring problems?

Question: I had a pretty confined fire in my
Small enclosed laundry room.  there was a lot of smoke, however. In the low ceiling is a light and i think it now sometimes flickers.  Electrician just looked at the outside of the fixture and said he can tell it's fine because it works.  Im still worried that something is wrong.  Advice? Pretty sure no flzme hit it but it got to 140 degrees and very black smoky.
Answer: At only 140 F there should be no problem, 140C on the other hand would have me checking the fixture and wiring insulation to see if anything melted. Most modern homes are wired with NMB wire that is rated for 194F in use (90 C). With the extra heat if an Edison (screw in type lamp) the center contact may have bent away from the lamp causing the flickering. With the power off remove the lamp and using a small screwdriver or other tool reach in and lightly lift the center metal tab, it won't take much and lifting two much can cause the tab to break (1/16 of an inch should be plenty) replace the lamp and see if that fixed the problem. Just a note that if this is a can light recessed in the ceiling they have thermal safety's that do go bad especially if a larger wattage lamp is used (larger than the fixture was designed and listed for)
Comment: Yes 140F. Same electrician does not want to instsll my washer in unfinished  basement using a GFI even though i keep reading it is required and I definitely want it so im just confused overall
Comment: Also do you think the smoke could have corroded the wires?
Comment: I think I would find a new electrician. If you wanted GFCI's on every branch circuit in the house the electrician may tell you why some circuits may have problems but should proceed with the work you want. I have done things in the past that were not good ideas but code legal then because I had explained what might happen got the job to convert back. Just wondering is this electrician licensed? Almost missed smoke, I doubt the smoke could have damaged the wires but heavy soot could cause a minor carbon path in extreme cases
Comment: He must be lisenced even if he didnt renew lately. We built our house and he was the electrician not working under anyone at all so i think we would not have gotten our CO or even electrical permit.  The GFCI is code as far as I know though i plan to call my town. I read something i have to admit not understanding that seemed to say new washers don't trip as much because of some change
Comment: also I'm overly cautious and never use higher wattage bulbs   most fixtures i have are 60 watt max and that's all I use. Hate to break the stack exchange rules but have to say thanks for you help.


Matching up cam lock or cam and groove coupling

Question: I am trying to select new hose cam locks to connect to cam locks on an existing pipe system. There seem to be a lot of different types of cam locks as I've searched for them, so I am unsure how I distinguish between them. Are there different swages, groove radii, or other variables that I need to measure so I can match up new cam locks, or are cam locks all the same and only vary by diameter? If there are measurable variables, is there a chart available that lists these variables (e.g. like the charts for measuring steel C-channel weights)?
Comment: Are you talking about cam-locks as in locks that keep a door closed or as in single pole power connectors? Just because both are common terms.
Comment: I'm talking about pipe or hose connectors. And I think I may have found my answer on Wikipedia. Oops. I should have stayed persistent.
Comment: Ah, a third option! If you want to post an answer based on what you found, it may help others in the future.
Answer:
Camlock connectors are capable of carrying liquids, powders and granules and are interchangeable with all other cam and groove couplings made to the same standard (A-A-59326A – formally MIL-C-27487),[1] ensuring compatibility with couplings made to the same specification.
  https://en.wikipedia.org/wiki/Camlock_(fluid_fitting)


Latex Tables in ipe

Question: I'm making a presentation in ipe. I have a table from a .tex document that I would like to include in ipe document. Is there any way to use the tabular environment or something similar in ipe?
Comment: no `tabular` would not give that error, `table` would, but you don't need `table` for a self-standing fragment. The whole point of table is to float to another page. I see you answered already!
Comment: I'd never head of IPE but http://ipe7.sourceforge.net/ says it can include fragments of latex, did you try it?
Comment: @DavidCarlisle ipe7 is exactly what I'm using. You can embed pretty complicated fragments of latex, but tabular complains because its not in an outer par environment
Answer: I was copying and pasting the tex from a paper, which included \table{} which pdflatex complained about, saying it's not in an outer par environment. By just using tabular, ipe was happy to include it, after I cleaned up some other issues that the latex code also had.
\begin{tabular}{|l l|l|l|}
\hline
Query Type  &                 &  Query Time         & Space   \\ \hline
Orthogonal: &   Standard  & $O(\log^{d-1} n)$ & $O(n \log^{d-1} n)$     \\
    &  SD fixed $m$                  & $O(m \cdot \log ^d n)$     &  $O(m \cdot n \log^{d-1} n)$     \\
    &  SD variable $m$               & $O(m \cdot \log ^d n)$     &  $O(n \log ^d n)$       \\
    &  SD size est.                  & $O(\log ^{d+1} n \log U)$  & $O(n \log^{d} n \log U)$         \\ \hline
\end{tabular}

Answer: Just a small addition to your answer.
If you would need to include a pmatrix instead of tabular into your figure, you also need to ask IPE to include the amsmath package. This is simple (taken from here). Click on Edit > Document properties (alternatively, press Ctrl+Shift+P) and type \usepackage{amsmath} into the "Latex Preamble" field.
You can also use this for changing fonts or doing anything else you normally do in the preamble of your LaTeX document.

Latex Tables in ipe


Is on-topic humor appropriate?

Question: I've just posted an answer that includes a link to an XKCD cartoon that is closely related to the topic.  Is it appropriate to include such humor in an answer?
Comment: And d) not attribute it?
Comment: The only crime is to A) not include the actual xkcd image and B) to not include the hover text. Oh, and C) to not include an actual answer along with it.
Comment: I've locked the post in question for the meantime (it will expire after one day), so that we can get this sorted out.
Answer: Absolutely it is.
As long as an answer still answers the question, linking to external resources, be they serious or comedic, is fine and actively encouraged.
This only becomes a problem when the humor is out of place or is the only thing in an answer, which is not the case here.
Comment: It's also a problem when the image is CC BY-NC licensed and the person included the image is not the copyright holder... (see my answer)
Answer: As long as the cartoon isn't the only component of the answer, it's fine. Pictures are encouraged to make up a supportive section of an answer. Having taken a look at your answer, it looks perfectly fine, you could always embed the picture :)
However, if an answer is only a picture, or only a link, or only a quote...
None Shall Pass!
Comment: The irony of this.
Comment: @ArtOfCode Yep :D
Answer: I hate to be a party pooper... but the answer as it was when I wrote this (see edit note) is infringed on XKCD's copyright.
You are required to:

provide the name of the creator and attribution parties
a copyright notice
a license notice (name and link to the CC BY-NC 2.5 license)
a disclaimer notice
a link to the material
the title of the material (I guess that would be "PGP")

Finally... all "user contributions" on stack exchange are licensed under the CC BY-SA license which is incompatible with the CC BY-NC license.
I'm not a lawyer but I think because of this last point it might be illegal (criminal in some countries with severe statutory damages) to include an XKCD comic in your answer even if you comply with the 6 things I listed above.
Thene answer including the comic can (and probably will) be used for commercial purposes. The XKCD's license prohibits releasing the comic under a license that allows commercial use.
This answer has some relevant details: https://opensource.stackexchange.com/a/1252/436
In summary, on topic humour is appropriate but not when it's licensed under terms that prohibit posting it here. You can probably only post a link to the comic page, rather than the image.

edit note
The answer in question originally contained a link to the comic, then somebody else edited it to include the image, and it has now been reverted back to having just the link.
Comment: I followed the instructions on the XKCD site.  Someone edited the link.  I deliberately did not copy the image to SE for the reasons you mentioned.
Comment: You are allowed to link to the image. I'm not sure I see much wrong in that.
Comment: @Zizouz212 you can link to the image, but you can't distribute copies of the image, which is being done here.
Comment: I've rolled back the edit, to make it a link not an embedded copy.
Comment: @GlennRanders-Pehrson ah thanks, I've updated my answer to contain a summary of the confusion... I even looked at the edit history but because it highlights text in red/green (doesn't work on images) I failed to notice that somebody else embedded the image in your answer.
Comment: @GlennRanders-Pehrson I followed [xkcd's license](http://xkcd.com/license.html) to the letter when I embedded that comic."That is, you don't need my permission to post these pictures on your website (and hotlinking with  is fine); just include a link back to this page"
Comment: The trouble is that by embedding, it becomes CC-BY-SA (losing the -NC restriction), as stated in this answer. BTW, whether it's right or wrong, there's a large number of embedded XKCD comics, more than I care to count, on stackoverflow.
Comment: @AbhiBeckert Hmmm, Super User uses it for not-found pages.
Comment: @Zizouz212, perhaps they got a dispensation for this use.

Is on-topic humor appropriate?


Do you know a good forum/site to send in your hand cipher

Question: Is there any forum or website on the internet except reddit subs where you can send in your hand cipher to get it analyzed?
Comment: I've migrated here to meta as asking for references is off topic; asking about what's good is opinionated - another reason for being off topic - as well. Maybe somebody here is willing to answer though.
Comment: Could you clarify by "get it analyzed", did you mean to just get the hand cipher solved? Or to analyze deeper like the strength and the weakness?
Comment: I mean the latter
Comment: Is reddit's /r/codes not good enough? And for attempts at more serious ciphers, there is a dedicated thread in /r/crypto for it
Comment: The thing is I have already posted the cipher in r /codes and took their advices I even had a private conversation with an user who was really eager to study my cipher but unfortunately in the end he admitted that he (quote) :"doesn't have that kind of advanced knowledge"
Comment: Do you think I could post the cipher in r/crypto without getting the post deleted?
Comment: @user65597 In the dedicated review thread, yes, but not outside it (I'm a moderator there, so I should know). https://www.reddit.com/r/crypto/comments/9kk5gl
Answer: You can ask such questions on PuzzleSO. They have a cipher tag which has currently 1186 questions.
The tag has the following definition:

A cipher is a simple method of modifying messages to make them unreadable, but still possible to recover. Common ciphers are Caesar, Vigenere, Atbash, and several types of substitution cipher. Other ciphers include polynomial ciphers such as Playfair, Foursquare, etc
Comment: Note that [Puzzling.SE] is a recreational site, and they will only try to solve the cipher for fun, not deep-analyzing the cipher as per IT security field.
Comment: Do you know any alternatives
Answer: The first solution
I suspect that this is an example of an XY problem.
What you want is analysis of your cipher. The pre-supposed solution is to find someone else to do that analysis.
I propose that you already have someone to do that analysis: You!
Try to find a pre-existing design that is similar to yours that has attacks against it. Or find a course on cryptanalysis of (classical) ciphers. Or just sit down and think about what information you have and how you can use it.
Until you are already familiar with all of the standard and/or generic approaches to attacks, then asking for others to do the analysis is counter-productive towards your own education (which is what I presume designing classical ciphers is for) and will not improve your ability to construct superior designs.
Asking questions on crypto.stackexchange
If you are really stuck, and you can make your question narrow and precise, then asking for help on the main site is fine.
However, it is important to note that posting your design and asking for someone to break it is thoroughly frowned upon, and such questions will be closed. We require that you list what you have tried, and where you are stuck.
You would need to have a concise description of the relevant part of the algorithm that you have a question about. It should not be a code snippet - we are more of a math site than a programming site, so explain the design in mathematical terms as best as you can. Try learning to use TeX, it will help the reception of your question significantly.
If in doubt, look for old questions about algorithm design and classical ciphers that were not closed, that received positive votes, and that received answers. Then use such questions as a template to ask your own.
Ask in chat
Once you have sufficient (20) reputation points on the main site, then you can use The Side Channel, which is the chat room for cryptography.stackexchange. You can ask about anything you want there - however, you are not guaranteed an answer.
The pre-supposed solution
I leave this to others to find recommendations here - I don't know of any.
Until you have a design that is noteworthy in some sense (very fast, provably secure, existing analysis, etc) then few knowledgeable people will be interested/willing to work on it.
Comment: @user65597 I'm not sure it's possible to objectively (e.g. quantitatively) remark on the probability that experts in general will/will not be interested in examining a given design. So in that sense any such commentary *must* be subjective.
Comment: "Until you have a design that is noteworthy in some sense (very fast, provably secure, existing analysis, etc) then few knowledgeable people will be interested/willing to work on it."
Comment: Isn t that rather subjective?
Comment: That is right of course


Why some textures become black in GDX

Question: I have such situation in my GDX game: I have a static class that manage my Drawables. It's a Singleton. I want to load all my Textures to it in order not to load them at every turn when I switch between screens (I know this is bad practice but I need this). I pack my resources into a TextureAtlas and load them. But when I pack and load more then some amount of Textures and try to use them some of them become black. Why this is happens? How can I bypass this unfortunate case. The size of my TextureAtlas (four images and one .txt file) is about 4MB.
Comment: I suggest that you learn to use a graphics debugger. The OpenGL debuggers are jokes compared to the D3D debugger, but there's some half-usable options: https://www.opengl.org/wiki/Debugging_Tools . Not using a graphics debugger is as silly as not using a code debugger: it's like trying to run a marathon with your shoes tied together.
Comment: You know that texture sizes mostly need to be a power of 2
Answer: https://github.com/mattdesl/lwjgl-basics/wiki/LibGDX-Textures
Read this and especially Hardware Limitations part. Each phone/pc has it's max_texture_size and if exceeded - will print a black texture.
Answer: If you have bad texture coordinates this can happen. But it could be your texture atlas itself is wrong or you even try to use the wrong atlas. So check that as well.
Answer: Well. I hope this will help somebody. Some of my textures were black because of their resolution. The resolution of one of them was something about 1200x2400 pixels.
If you have similar problem, try to juts decrease resolution of textures.
Comment: Please accept your own answer if that makes sense.
Answer: I was also getting a black square when trying to draw some of the textures on IOS. It turns out the problem was that I was using MipMap and the image sizes were not a power of 2.
texture.setFilter(Texture.TextureFilter.MipMap, Texture.TextureFilter.Nearest);

See:
https://github.com/libgdx/libgdx/issues/1296
OpenGL ES 2.0 support non-power-of-two images, but not for everything. Specifically, it does not require support for repeat or mipmap with non-power-of-two textures. If you require those features, you should use power-of-two images

Why some textures become black in GDX


Were the Jews allowed to crucify Jesus themselves?

Question: In John 19:6 Pontius Pilate says  "Take ye him, and crucify him: for I find no fault in him." Does this imply that the Jews were allowed to crucify Him? If so, why didn't they do that?
Comment: I migrated this question from [Christianity.SE] because it seems like a question about a specific Biblical passage that doesn't require any particular Christian doctrine to explain.
Answer: Crucifixion was a Roman punishment, not a Jewish one
You will find part of the answer to your question in the previous chapter of John, wherein the Jews explain that they are not authorized {under Roman Rule} to put a criminal to death. John 18: 28-31

28 Then they brought Jesus from Caiaphas to the praetorium.* It was
morning. And they themselves did not enter the praetorium, in order
not to be defiled so that they could eat the Passover.    29 So Pilate
came out to them and said, "What charge do you bring [against] this
man?"    30 They answered and said to him, "If he were not a criminal,
we would not have handed him over to you."    31  At this, Pilate said
to them, "Take him yourselves, and judge him according to your law."
The Jews answered him, "We do not have the right to execute anyone,"

Granted, the Mosaic Law had a variety of crimes that were punishable
by death.  Examples include:

Exodus 21:12-17

12 Whoever strikes someone a mortal blow must be put to death.    13
However, regarding the one who did not hunt another down, but God
caused death to happen by his hand, I will set apart for you a place
to which that one may flee.    14  But when someone kills a neighbor
after maliciously scheming to do so, you must take him even from my
altar and put him to death.   15 Whoever strikes father or mother
shall be put to death.   16 A kidnapper, whether he sells the person
or the person is found in his possession, shall be put to death.    17
Whoever curses* father or mother shall be put to death.

The Empire of Rome reserved to its own authority capital punishment in this conquered territory of Judea.  The passage in John 18 reflects that, and alludes to why the Jews in this case (because they held blasphemy to be worthy of the death penalty) had to get the Imperial authority involved to get that sentence passed on this (in their eyes) criminal. From the Roman point of view, it wasn't blasphemy that was the capital crime but rather sedition.

Jesus stood accused of sedition, not blasphemy—a civil crime, not a
religious one. Rome's punishment was a painful, and visible, death by
crucifixion. In the age of Roman domination, only Rome crucified. And
they did it often. {snip}  Clear evidence of the political nature of Jesus's execution — that Pilate and the high priest were ridding themselves of a "messiah" who might disrupt society — is the sign Pilate demanded be affixed to Jesus's cross: a scornful signal to the crowds that this death awaits any man the pilgrims might proclaim "the king of the Jews."

Jesus: Rediscovering the Mysteries Surrounding Christ's Resurrection Johnna Rizzo
Comment: I suspect that Pilate was simply engaging in a bit of sarcasm. As the local Roman governor, he knew very well that Rome reserved the imposition of capital punishment for itself. "Go do it yourself" was probably equivalent to, "Sorry, it ain't gonna happen."
Comment: But is only Rome could crucify Him why did Pilate proposed this to the Jews?
Comment: @Marijn The interpretations on that vary.  Attribution as to his precise motive will involve a bit of speculation, but on the practical side, Pilate had a political problem to try and solve that involved both the threat of sedition and a local leadership of the people Rome was ruling who were appealing to Rome's authority to hand out a sentence that they could not because they were under Rome's authority.  By the way, that's a separate question that you ought to post separately.  You asked why the Jews didn't, and I think I covered that.


How to learn IP addresses in a LAN

Question: For communication with machines in the same LAN, hosts do ARP for translating the IP address to MAC address, which means, IP addresses are already known to each other. My question is, how does the host come to know about the IP addresses of each other in the first place?
Comment: Most applications use DNS names that are resolved to IP addresses. However, applications and protocols above the transport layer are explicitly off-topic here, see the [help].
Comment: Did any answer help you? if so, you should accept the answer so that the question does not keep popping up forever, looking for an answer. Alternatively, you could post and accept your own answer.
Answer: Most often, hosts use DNS to get the IP address from the host name.
Comment: @Network_starter DNS is an application-layer protocol (off-topic here) that works globally. MAC addresses are only meaningful within an L2 segment, so propagating them outside is useless.
Comment: Does DNS work only within LAN boundary? Also, if some protocol like DNS offers to share the IP address of some host, is there any reason, why MAC address can not be shared in the same response as well?
Answer: Some application on one hosts needs to communicate with an application on another host. Either the IP address of that other host is configured in the application, or DNS is used to look up the IP address of a name (for example www.example.com is converted 192.0.2.123).
Comment: Some application must initiate traffic to a specific destination, and that application either knows a hostname or an IP address where to send that traffic to  mDNS can be used to discover which hosts are available on the network and thus used to convert a hostname into an IP address.
Comment: @Network_starter mDNS and DNS are different application-layer protocols (all off-topic here) albeit for the same purpose.
Comment: Is your real question "why use IP if you have MAC addresses?"
Comment: Okay. But, I am considering the case, where destination IP address is not pre-configured in this host. in such cases, is it always DNS or some other mechanism is also possible? Also, is this DNS same as mdns?
Comment: Okay, got it. But, one doubt is, if mDNS is used to learn about hosts and their IP addresses, it means, those hosts must have registered their host name and IP address in some server, so that, any mDNS query can send the reply back. If this is correct, why not those host also register their MAC addresses as well during the registration, so that, ARP broadcast may be avoided? Am I missing something?
Answer: if host A needs to communicate with host B, host A needs to know host's B address. It may be not an MAC or IP address, but it needs to be some address.
One common pattern is DNS, as described in other examples. Host B has a name. A network is running a service that allows to map host B's name to its current address. Important here is that (1) A has to know B's name, which btw can also be considered an address and (2) A knows how to reach DNS service, so A somehow knows its address.
There is a different available model, which is based on the concept of services. Services are some functions that can be performed by hosts/other network components. Some hosts provide services (aka are service providers). If other hosts want to use a service, they do service lookups which returns IP addresses of hosts(s) which provide the service. It can work other way around, each service provider periodically announses that it provides a service.
Service announcements and service lookups usually work by having well-known broadcast/multicast addresses for services. Service providers periodically broadcast announcement messages. Host, who lookup services, send discovery messages to well-known multicast addresses (and hope for reply :)). Examples of such a services are DHCP and IPv6 stateless address autoconfiguration.
Here is a wikipedia article for this. It has a couple of links with info. There is a mechanism called DNS-SD that allows to use DNS records for this. I think Multicast-DNS works like this too. And it has a couple of useful links.

How to learn IP addresses in a LAN


Bitcoin exchange, local or foreign?

Question: If I live in the USA, and buy/sell bitcoins from a Japanese exchange, are their any advantages/disadvantages for doing this, instead of buying bitcoins from a USA exchange?
Answer: There are legal differences. I won't go as far as saying I can tell you if any of them are advantages or disadvantages, because I don't think I can.
If both your exchange company and their banking is in your country, then there is no question if there is any legal obligation on your part to tell your government that you dared move money outside the country. Check your laws; if you're middle class, you'll be surprised how low the trigger amount for such issues that you might think would afflict only the seriously affluent can be.
One thing that is not very different is that no bitcoin exchange I am aware of is fully compliant with all laws fit for all sorts of similar enterprises for every location where they do business, and most probably are not compliant in any or only in hardly any. Some like to advertise their compliance, but I suppose the one case (campbx) where I did get more information on that by inquiring is typical. They wrote me earlier this year that they were then only compliant with the (comparatively easy) Federal FinCEN rules, not the rather tough state money transmitter licensing, although they emphasized their efforts towards progress on that front.
Whilst you may argue that this is mostly because many people don't get how these laws cannot possibly apply to bitcoin businesses, that hasn't stopped authorities in some countries from temporarily seizing a bank account of a bitcoin exchange (one case I know of was in Poland, and one not related to such laws in Germany) or even seizing a bank account for forfeiture (one case I know of in the USA).
So this is not different, but still there is the subtle but important distinction if there is even a chance that your exchange will be allowed to remain in business and at least try to continue honoring its obligations to its customers (as happened with MtGox, even after a possibly minor bank account they had in the US was seized for forfeiture for failing to have state licensing).
I wonder if it would go the same way for an exchange based in the US. Or in comparable countries, for that matter. For a UK company banking in Germany and Poland, the empirical answer is no (bitcoin-24 stopped doing business after its German bank acount was temporarily seized and hence released back to them, and their Polish bank account was simultaneously seized but at least not completely released back to them yet). Again, I wouldn't even try to venture towards judging which is better and for whom.
Comment: It doesn't affect any bitcoins you have bought AND withdrawn to your own bitcoin wallet. Those remain useful (not _become_ as they were already useful before). It might affect those you have stored at the exchange, depending on how (and if) they segragate them, and how they treat them---after all, they have lost customer funds and might need to declare bankruptcy, after which all company assets could get equally divided across clients' claims. And if it affects you ability to purchase more bitcoins from that company depends on whether they remain open for such business.
Comment: I'm not 100% sure what this means?  If I use a US exchange to buy bitcoins for example, and the back account behind this exchange gets seized for whatever reason, what does that mean for me as a buyer of bitcoins?  Does it mean the bitcoins I bought become useful?  Or does it mean I can't buy any further bitcoins from that US exchange?
Answer: Even though it seems simple, this question is actually too complicated to answer.  It is also ill-defined, because the answer depends on who you are and what types of accounts you have access to, in which currencies, and in which countries.
Right now, I have accounts with all the major Bitcoin exchanges, and I have bank and brokerage accounts in many different countries and currencies.  Some exchanges refuse to do business with U.S. residents, while others require U.S. residency.  Some exchanges always convert the currency, others don't.
At present, I have found all the exchanges to be severely lacking in maturity, disclosure, and documentation.  The only exchange I deal with is Localbitcoins, because it is actually clear what the rules are and how it works.
I am sure everyone will vote this answer down, but the answer depends on who you are, what types of accounts you have access to, and what capabilities to transfer money those banks/brokerage houses have.  And where you live.
Comment: You make good points, especially the "it depends" part is true on many levels. But I am also confused by your answer: You have accounts with lots of bitcoin exchanges, but you only deal with one? Is there a meaningful way to understand this without assuming you have contradicted yourself?
Comment: Thanks for the comment.  In order to evaluate the exchanges, I have opened an account, verified my identity and address, and attempted to use the services.

The services are:  Bitstamp, BTC-E, CampBX, Coinbase, Coinmama, Coinsetter, ItBit, Localbitcoins, Mt. Gox, and Bitbargain.

In all cases, the services are immature and inadequate, except for LocalBitcoins and Bitbargain.  I use LocalBitcoins because it is cheaper than Bitbargain.

I live in the UK, and the UK national bank system offers instantaneous transfer.  As I said, your situation may differ.
Comment: I see. Thanks for clarifying what you meant.
Comment: That is true too.  Over the years, I have opened many bank and brokerage accounts, but I really only use a small number of them, depending on what I am trying to accomplish.
Comment: Err, now I have to apologize for apparently editing my comment you replied to without realizing you must have already been typing your reply. Originally, I had included "That sounds like having opened many bank accounts, but only having money in one of them."

Bitcoin exchange, local or foreign?


Vega and Gamma signs

Question: Do vega and gamma always have the same sign (ie both positive or both negative)? Under what circumstances can they have opposite signs?
Comment: In Black Scholes Model ?
Comment: For a long option position they are both positive and for a short option position they are both negative. ("option" = vanilla call or vanilla put). So yes, they always have the same sign.
Answer: Usually vega and gamma go in the same direction, but you can have opposite exposure in a calendar spread.
For an ATM option, vega decreases closer to maturity while gamma increases. If you implement the following:
-long a 1 month ATM option
-short a 2 months ATM option
you should be long gamma and short vega.
Comment: By the way that's called a "short ATM Calendar Spread".
Answer: In the Black Scholes model, for an European option, we have
$$\text{Vega}=Ke^{-r\tau}\phi(d_2)\sqrt{\tau}$$
and
$$\Gamma=Ke^{-r\tau}\phi(d_2)\frac{1}{S^2\sigma\sqrt{\tau}}$$
thus
$$\frac{\text{Vega}}{\Gamma}=S^2\sigma{\tau}>0$$
Comment: Note that this is true for single European vanilla options. It no longer holds for portfolios of options. Even when the volatility surface is flat, you can build a portfolio of options with different maturities to obtain gamma and vega positions of opposite signs. Similarly, when the volatility smile of a maturity is not flat, you can achieve the same with a position in different strikes of that maturity.

Vega and Gamma signs


What topics should be discussed here?

Question: There are many people who don't seem to like the quality of questions that are on this site, and there's probably a half dozen questions on Meta about should something be on topic for this site. Perhaps it's easier to just ask in one place. What should this site be all about? I don't want to hear about things it shouldn't be about, only about what it should be about. Please limit your ideas to no more than a few related subjects per answer, feel free to answer more than one if you'd like. Please vote up the answers you would like to see included, and down the answers you would like to see removed. Add comments if you think you can add to the discussion of a particular topic
Comment: Calling it "Grumbling" doesn't help your case. Please understand that this site *will* be closed down if the Stack Exchange employees think this site isn't working, and the people more experienced with Stack Exchange are the very ones who can help the most.
Comment: I'll make it a bit nicer, but the point of this thread is to try and figure out what this site should be about. There are definitely some nuggets in the dirt of this SE site, and I'm just trying to figure out what we all agree are the nuggets, so we can keep them and keep the site as a whole functioning.
Comment: The reason why the information is hard to find on Meta is that there is no consensus yet. I recommend participating on Meta threads on a specific topic (by voting on answers you like, or adding your own if you have new arguments to contribute).
Answer: List of books that feature a particular technology, theme, or idea (Books or movies dealing with the early colonization of Mars, What movies feature time travel as a central plot device?)
Answer: Obscure triva requests (What was Shepard Book's past in Firefly?, In the Dune series, why are they not using computers and programming related technologies?)
Answer: How Sci-fi and reality mix (IE, What FTL drives might be possible, Could electronics be developed by water-based life forms? What would they be like?)
Answer: Questions gathering common related sci-fi technologies into one question (What are the different types and classes of FTL engines?)
Answer: Topics relating Sci-fi books to movies (When we will see Pierson's Puppeteers on the big screen?, What are the Least faithful movie adaptation of a sci-fi book?)
Comment: @Dori Then vote it down. I'm fine with that.

What topics should be discussed here?


Deleting an accepted answer

Question: I gave a wrong answer to a question, but the asker accepted it. I added a second (correct) answer, because completely changing an already accepted answer felt wrong to me. What can be done, if the asker doesn't remove the accept flag?
Comment: "because completely changing an accepted answer felt wrong to me" - I don't understand your reasoning behind that. If your answer is false but already accepted, and OP doesn't respond to a request to un-accept it, changing the accepted answer is infinitely better than having a wrong accepted answer on the site. That said, in this specific case it probably doesn't matter as the question very unlikely to help any future visitors regardless...
Comment: *"if the asker doesn't remove the accept flag"* ... nothing
Comment: You could potentially flag for moderator attention and explain the situation. But still the easiest is a simple request to the OP to unaccept.
Comment: @l4mpi Upvoters and downvoters aren't alerted when an answer is edited, so completely changing it is rather dishonest, especially when it was accepted/highly upvoted.
Comment: @l4mpi, for some silly reason, we think the asker is important and award his or her judgment some special meaning. If that person says a totally wrong answer solved their issue, we have to go with it. It's silly, but those are the rules. If we then change what the user said fixed the problem to something else entirely, we undermine the checkmark and all the silliness that goes along with it.
Comment: +1 for the desire - and taking action - to curate your content for quality!
Comment: @l4mpi The difference between "improving the answer" and "changing the answer" is that after changing it, the answer won't necessarily still apply to those who upvoted it because it solved their problems.  If you change it, those votes are now a lie.  _Improving_ the answer without changing it does not invalidate those votes.  wheaties' answer is somewhere in the middle.
Comment: I've voted to delete it. 2 more 20k+ users and it should disappear. :-)
Comment: I say it would be nice if (a) wholesale changes to an answer automatically invalidated the checkmark or (b) the answerer could simply reject it (perhaps within a *reasonable* timeframe, to prevent coming in months/years later and just rage quitting). I don't know if either has been proposed and/or shot down, however.
Comment: It's deleted now.
Comment: @CodyGray and @ kapa thanks for your help! Is this the only way?
Comment: It's been deleted by the community now.
Comment: @l4mpi seems true for this special case. But for [this question](http://meta.stackoverflow.com/q/258602/2932052), it was just an example.
Comment: @Izkata that reasoning implies that the new answer does not solve the problem anymore, which seems unlikely. You're also implying all upvotes come from people with a similar problem who found the answer helpful, not just from random users who upvote a seemingly plausible but wrong answer. But I think we're mostly on the same page here - if the wrong answer contained helpful content, this should not be deleted by an edit unless it would become redundant (and given it is on-topic and related to the question, of course).
Comment: WHAT? How can a accepted answer be deleted? In some other Meta post I red that "an accepted answer can't be deleted .. not even by Moderator". Then how this deletion was made possible?
Comment: @Rahul Users with 20k+ reputation and moderators can delete any answer, regardless of whether it is accepted. What they *cannot* do is remove the accept checkmark or switch it to another answer. Only the person who asked the question can do that.
Comment: @CodyGray, Thanks for the info. I am approaching towards that :)
Answer: If you have the ability to edit your answer then...

Disclaimer as to why the original answer is wrong
Correct Answer
blah blah blah
Previous Answer
blah blah blahty blah

That's what I'd do so that people who come to it (especially the person who asked) knows that the accepted answer was wrong and why. Why is very important
Comment: I like this option far better; Deleting your old answer removes the data, which might be interesting to see for archives sake.
Comment: I think it's useful to leave the old answer in so people can easily see what was accepted.  Sometimes people are wrong about being wrong.
Comment: You don't necessarily have to actually leave the previous answer in - it's always still available via edit history.  Just mention that you changed it and why, and specifically reference the edit history link.
Comment: This is exactly what I do, usually when OP adds some information regarding her question or comments on some specific aspect of my answer +1
Comment: This is what I was going to answer with when I saw the question.  And agreed with leaving the original in the body of the text rather than relegating it to the edit history (unless the change is fairly minor).  Convincing incorrect answers, so long as there is an actual correction, can be very informative.
Comment: Keeping the old potentially incorrect answer & revising your post to also include a new updated answer ensures any comments made during the old answer will still hold their value, rather than seeming irrelevant if the new answer voids any comments.
Answer: I did the same once, then I flagged my answer as "Other" and explained, Moderator "unaccepted" my answer, then I deleted my own answer.
So the easiest way is to flag your answer as "Other" and explain, leave the rest for moderator.
Comment: Moderators cannot 'unaccept' an answer. If your answer was unaccepted, it was done by the OP themselves. Moderators can only delete the post.
Comment: @whe Yes, this is a good option, if the correct answer is already given by another one (+1). But in cases like mine, I now think it's better to follow [wheaties's suggestion](http://meta.stackoverflow.com/a/258638/2932052)
Comment: I just wanted to add my situation, otherwise I too support wheaties's answer :)
Comment: I'm pretty sure that moderators can't unaccept your answer, unless it is *their question*. They can delete it, of course.
Comment: happened to me, don't know how.
Answer: It happened to me once. I realized that it was no doubt at all that the answer was wrong, and also was misleading to future readers. I edited the answer to something like:

This answer was wrong, but I cannot delete because it is accepted

and then I reported it.
Comment: Consider if [the solution explained by wheaties](https://meta.stackoverflow.com/a/258638/2932052) would be better. I personally found it best, but of course it depends also on the presence of competing answers ...

Deleting an accepted answer


Two Dehn fillings yielding the same lens space?

Question: Let $M$ be an oriented three-manifold with $\partial M$ a torus. Suppose that two different Dehn fillings $M(r)$ and $M(r')$ are (oriented) homeomorphic to a lens space $L(p,q)$.
Does that imply that $M$ is a solid torus?
Answer: This is a case of the oriented knot complement problem in lens spaces, also called the cosmetic surgery problem. If $M(r)\cong M(r')$ preserving orientation, then these form a purely cosmetic (or truly cosmetic) pair. See Problem 1.81 (A) from Kirby's problem list (posed by Steve Bleiler).
You probably want to avoid reducible examples like that given in Mukherjee's answer (note that this hypothesis is missing also in the statement of Problem 1.81).
Given that assumption, there is no such example which is irreducible and non hyperbolic by a result of Daniel Matignon (he classifies all cosmetic surgeries on such manifolds, and shows that all the examples are chiral cosmetic pairs, i.e. orientation-reversing).
There are examples of cosmetic surgeries on hyperbolic knots in lens spaces that reverse orientation, but I think the orientation preserving case is still open in general.
By the way, maybe the interesting case of this question is for $M$ not a homology circle. Otherwise, the two surgeries must lift to the $p$-fold cyclic cover of $M(r)\cong M(r')\cong L(p,q)$, and hence one would have two surgeries on a knot yielding $S^3$, a contradiction to the knot complement theorem.
Comment: To follow up on Ian's comment, perhaps the simplest hyperbolic manifold which admits an L(p,q) filling and an L(p,-q) filling is the figure eight sister manifold (aka m003) which admits an L(5,1) filling and an L(5,-1) filling. The homology of the figure eight sister manifold is ZxZ/5Z.
Answer:
Here is an easy example. Consider M as the 3 manifolds obtained by the surgery on the two black curves ( $0$ surgery on one unknot and $p/q$ surgery on another unknot) and take a neighborhood of the pink curve out. Clearly $M$ is not a solid torus (compute the fundamental group). Now if you do any Dehn filling with integer co-efficient, the 0-framed unknot will cancel that out and you will be left with a lens space $L(p,q)$ which is $p/q$ surgey on the unknot.
Comment: That is an unknot in L(p,q), so is reducible. Probably @Adam should assume the manifold is irreducible to avoid such examples.
Comment: Yes, that question would be more interesting. But the way he asked, I think this is a quick counter example.
Comment: Agreed. The answer would be more clear if you just drew a 2 component unlink with p/q surgery on one component.
Comment: Thank you, Anubhav and Ian. Somehow I missed it, but indeed requiring M irreducible makes the question more interesting :-)


Import 256 bit private key

Question: Can I import a 256 bit private key in a Wallet (binary format)?
Or do I have to convert it in another format?
Comment: It all depends on the wallet, sometimes it's not possible to directly import a private key, sometimes it uses some specific format (for example WIF for Bitcoin Core). I think you should be more specific or really we can't help much.
Answer: dumpprivkey in bitcoin core returns private key in WIF
importprivkey adds a private key (as returned by dumpprivkey) to your wallet.
Private key to WIF: https://bitcoin.stackexchange.com/a/99101/
Answer: Most wallets (and by that, I mean almost all) will not accept a binary 256 bit private key, you will have to convert your 1's and 0's to a WIF format.
There are libraries in python and javascript (and I'm sure other languages too) available that can do this function conversion for you.

Import 256 bit private key


Obtaining phases of all basis states

Question: I'm wondering that is there a way to separate phases of basis states from the magnitudes (namely putting phases on some new basis states with the same probability magnitude) if the exact values of phases and magnitudes are unknown? One way I can think of is the quantum phase estimation routine. But to me it seems this method can only estimate one single phase at a time, so if there are a lot of basis states it will take a lot of time to estimate all the phases.
Answer: So, are you asking whether it's possible (in the qubit case) to perform an arbitrary map of the form
$$
ae^{i\theta}|0\rangle+be^{i\phi}|1\rangle\rightarrow \frac{1}{\sqrt{2}}(e^{i\theta}|0\rangle+e^{i\phi}|1\rangle),
$$
if $a$ and $b$ are unknown real numbers satisfying $a^2+b^2=1$? If this is the case, this is impossible.
Consider a simple case where instead of completely arbitrary values, you're either given $a|0\rangle+b|1\rangle$ or $a|0\rangle-b|1\rangle$. Your map would require these to be converted into the states $(|0\rangle\pm|1\rangle)/\sqrt{2}$, which are orthogonal. This means that your map would facilitate cloning of those two original states (because I can measure the outcome and know which state I had, so I can prepare many copies), which must be impossible because the two states are not orthogonal if $a^2\neq b^2$.
Comment: I am thinking  to have n qubits as ancilla qubits (assuming originally we also have n qubits) so that the phases can be transferred to the ancilla qubits (the ancilla qubits are now 1/√2(eiθ|0⟩+eiϕ|1⟩ and the original state becomes a|0>+b|1>) , so in some sense the absolute values and phases are 'decoupled'. Does this process involve cloning?
Comment: My objective is only to obtain the values of the phases (of course the 'decoupling' I mentioned is better if it is possible). I think it is actually possible through quantum phase estimation it is just it is too tedious. By the way I came across this paper http://iopscience.iop.org/article/10.1088/1367-2630/aafb8e/pdf which seems to provide a solution but I can't be completely sure since I cannnot understand it completely...
Comment: In my example, any deterministic way that would let you distinguish the phases $\pm 1$ on the $\ket{1}$ component implies cloning. Alternatively you could potentially use optimal cloning-type arguments to put an upper bound on the success probability of any such protocol to determine the $\pm 1$ values.

Obtaining phases of all basis states


What is the difference between a monocoque and semi-monocoque fuselage type?

Question: What are the main differences between these two types of fuselages?
Answer: A monocoque fuselage has its skin holding the skeleton structure together while the semi-monocoque has both the skin and the skeleton holding together. Semi-monocoque also has "stringers" running horizontally down the plane to help hold the frame together. The monocoque fuselage also cannot be used for airframes after a certain size (small aircraft with single engine), but the semi-monocoque has been used from single piston engines to commercial airliners.
A monocoque design would also have a safety risk involved if the skin was damaged because it is the load-bearing structure.

Image and some text source
Comment: A semi-monocoque design also has a safety risk involved if the skin is damaged, because it is still a load-bearing structure.
Answer: The main difference between the two is the way the loads are carried by the aircraft structure.
The earliest aircraft had an underlying truss structure that carried the load, with fabric covering this load bearing skeleton. The outer shell carried no loads and from the structural viewpoint, was basically dead weight. The image below shows the underlying structure of the Blériot XI

By J.Klank - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=7219409
Later, the aircraft structure was designed so that the the skin itself was a mainload carrying member. This type of construction was called the monocoque, which is a French term for single shell (or hull). A good example is the fuselage of the De Haviland Mosquito (which is all the more impressive as it was made of plywood). The fuselage was made in two monocoque halves, which were joined together, which can be seen in the following figure.

De Haviland Mosquito monocoque structure- image from pistonwings.tumblr.com
As the skin carries the entire load, the strength requirements mean that this technique cannot be used for aircraft beyond a certain level. For thin skinned structures, buckling is critical issue, which affects the load carrying capcity. Large structures can be made that can carry load only via the skin, but support is still required. For example, the fuel tanks of Altas ICBMs carried the entire load on the skin, but required internal pressure to maintain the shape, without which they collapsed.
The semi-monocoque is in between the above two- here, a stressed skin is used that takes some of the load, but is reinforced by the underlying structure, which also takes load. Basically, both the skin and the underlying structure share the load. Most of the aircraft today use this type of construction, from small GA aircraft to the large commercial airliners. For example, the image below shoes a fuselage section of Airbus A350XWB, which features this type of construction.

Image from a350xwb.com
Comment: `As the skin carries the load, the strength requirements mean that this technique cannot be used for aircraft beyond a certain level. Most of the aircraft today use this type of construction.` Something's missing there - which is _this_ type of construction that most aircraft use today? Also, can you expand on the _certain level_ that, once exceeded, prevents the use of monocoque construction?
Comment: @FreeMan You're correct. Quite a large chunk is missing. I've edited it. Thanks for catching.
Comment: Makes much more sense now!  :)


Green caterpillars pest on kale, what to do after finding and removing the pests?

Question: I had recently discovered and removed what appears to be Cabbage loopers on some of my kale, as shown in the images below.
What is the best decontamination procedure after removal? Should I give the plants a thorough rinse and transplant it with some fresh potting soil?
Answer: No point washing the plant or changing potting mix. You could look on the leaves and remove the eggs weekly (most likely on the underside of the leaves).
Answer: These are probably cabbage loopers. You can use the biological control Bacillus Thuringiensis, commonly known as BT. It is a bacteria that infects many caterpillars, causing them to stop eating and they starve to death. It is non-toxic to humans.
Answer: The caterpillar that you have there is from the white moth. They are all over my garden. I literally harvested some lettuce + arugula today and made a salad and found about 5-6 of those caterpillars on the leaves. I rinsed the leaves with water best I could and enjoyed the salad.
I wouldn't over think it. I'm sure I've probably missed a few in my life and actually eaten some of those caterpillars. To reduce the number of caterpillars spray a neem oil solution on the leaves especially the underside of your leaves.


I want to know if I can patent such algorithm?

Question: My algorithm uses the modified version of existing algorithm (architectural modification) and I have combined it with existing mathematical law. so can a patent restrict others form using such combination of modified algorithm with a Mathematical law?
Answer: I agree with George White. I have several algorithm based patents. In all cases, they patent the application of a novel algorithm to solving a very specific problem (analysis of real time PCR results). I've been told (I'm not a lawyer myself) that an algorithm, by itself, would be considered "abstract" and thus unpatentable.
Even if you decide on a specific application of your algorithm for the patent, it still needs to be novel and non-obvious to someone skilled in the art. Since you are modifying an existing algorithm and combining it with another existing mathematical law, the question the examiner might pose is whether the modification and combination is something someone skilled in the art might think of and is thus obvious. It might take a skilled patent attorney to draft and prosecute a patent against such a challenge.
Comment: And I agree with Eric.
Answer: It is possible but it would need to be applied to some useful end. Using the terms algorithm and mathematical law in the text of a patent application would liking get it rejected out of hand unless phrased very carefully.


Tossing the ball after tagging out an attempted steal at second

Question: I was watching a compilation video that included many clips in which a catcher, immediately after a pitch, threw to second base, and a fielder tagged someone out who was stealing from first. In many of those clips, you can see that fielder then toss the ball in the direction away from the pitcher, seemingly to the center fielder or the second-base umpire. Whom is he tossing it to, and why?
Answer: They're tossing it to a teammate.  It's a common thing to do after completing a play; it's sort of the baseball version of spiking the ball after a touchdown - but more respectful, not with the implication of belittling the opponent. You won't see it when there are other players on base unless it's the final out of the inning, or course.
I've always assumed that it was mostly a way to build team spirit - the out only really involved the catcher and the 2B or SS, but they throw it around the diamond to get the other guys in on the action. It's also a good way to practice throwing - while these guys are very good, more muscle memory is always a good thing.
Answer: It is common for the ball to be tossed around the infield after any out before the inning is over and there are no runners on base, not just after a caught stealing.
Per https://en.wikipedia.org/wiki/Glossary_of_baseball_(A)#around_the_horn

The infielders' practice of throwing the ball to each other after recording an out, provided there are no runners on base. The purpose is as much traditional as anything, but it also serves to keep the infielders' throwing arms active.