Is art a form of communication?

Question: I recently got into a discussion where the other person claimed that art is a form of communication. Bearing in mind that the definition of art is disputed, did any philosophers argue that a work requires an emotional state or an idea to be transmitted between two parties for it to be considered a work of 'art'? If so, does the communication have to be intended by the author or can it be incidental?
Comment: how is this not opinion based?
Comment: [Yes, it would](https://philosophy.stackexchange.com/help/how-to-ask).   Are you asking whether art can be used to communicate, or whether communication is required for something to be considered art?  Is "communication" well defined?
Comment: I edited your question to make it comply with our policies, you can edit further or roll back the edit if it does not agree with your intentions. That art communicates *something*, and that most artists intend it is an empirical fact, what "something" is is more controversial, see [IEP on Art Expression](https://www.iep.utm.edu/aestheti/#H7), [Mothersill's Is Art a Language?](https://www.jstor.org/stable/2023126) and our [Is music just another language?](https://philosophy.stackexchange.com/q/36693/9148) thread.
Comment: Would that invalidate my question?
Comment: @user38026:  why should it matter?  Sometimes people want to hear other people's opinions.  If I ask "Is green the best color?" I might get some good expositions on the color green, even though it is totally objective.
Comment: Among musicians (I've played jazz guitar professionally for years) we say that "art is the communication of feelings".
Comment: "*Music is a kind of 'nonsense' that everyone understands.*" Et tu, arte?
Answer: Beethoven is reported to have said (my emphases added to highlight the connection to the question)

When I open my eyes I must sigh, for what I see is contrary to my religion, and I must despise the world which does not know that music is a higher revelation than all wisdom and philosophy, the wine which inspires one to new generative processes, and I am the Bacchus who presses out this glorious wine for mankind and makes them spiritually drunken. When they are again become sober they have drawn from the sea all that they brought with them, all that they can bring with them to dry land. I have not a single friend, I must live alone. But well I know that God is nearer to me than to other artists; I associate with Him without fear; I have always recognized and understood Him and have no fear for my music — it can meet no evil fate. Those who understand it must be freed by it from all the miseries which the others drag about with themselves.
Music, verily, is the mediator between intellectual and sensuous life.
Speak to Goethe about me. Tell him to hear my symphonies and he will say that I am right in saying that music is the one incorporeal entrance into the higher world of knowledge which comprehends mankind but which mankind cannot comprehend.
Comment: While this is a nice quote from Beethoven I don't see how it answers the question. Is art a form of communication according to this quote? What does it communicate exactly?
Comment: @eliran Beethoven I cannot improve! And he covers the question. But some may find him too poetic to be clear. So I've made a separate answer and left Beethoven alone!
Comment: Pertinent question @Eliran. Need to run just now (doc). Will write in a bit.
Answer: Communication is merely the act of sharing mental contexts: thoughts, ideas, knowledge, feelings, perceptions, etc... Any human sense can be used as a channel for communication by codifying a mental context into a form perceptible to that sense. For instance, if I tap someone on the shoulder, click my tongue, and point, I can effectively communicate an intention. Communication is a mysterious and poorly understood activity, but it is not difficult to see because it infuses most of human life.
Art is always an attempt to share a mental context  usually an emotional context — and so art is always a form of communication.
Of course, every channel of communication is subject to static and white noise: mere production of sensory experience not codified to share any significant mental context. On a certain level humans (like parakeets) are comforted by bland sensation, a kind of primal instinct that feels the world in safe so long as there is an ongoing stream of insignificant experiences. But we should not allow such noise to drown out the signal.
Comment: Is art _always_ an attempt to share a mental context? Can't I paint a painting simply to enjoy the process, or is that a form of communication as well?
Comment: In the most trivial sense, every form of expression is meant to share a mental context. When a mother picks up an infant and sings a nursery rhyme, she is trying to communicate a calm, happy, sleepy mental state to the infant. But if you mean communication in the non-trivial (serious) sense of the term, then not even language is always an effort to share a mental context.  A good 90% of modern media is mere drivel with no purpose except to fill silence. If you want to vapidly enjoy yourself you can paint, talk with a friend about The Bachelorette, post something on Twitter...
Answer: I agree with Rusi's answer. This provides another way to consider art as a form of communication even when unintended.
Michael Polanyi claims the following about knowledge in general: (page 7)

...all knowledge is either tacit or rooted in tacit knowledge.

If that is the case then any form of explicit communication is rooted in tacit knowledge. This may help answer the OP's second question:

...does the communication have to be intended by the author or can it be incidental?

Whatever the author is explicitly trying to communicate can be considered a form of knowledge. If so it is rooted in tacit knowledge even for the author. The full communication is more than what is intended by the author and so there is an "incidental" or tacit component.
Then consider the first question:

...would you agree that a work requires an emotional state or idea to be transmitted between two parties for it to be considered 'art'?

The author may have no explicit intention to communicate anything to the reader.  However, the communication itself creates an explicit statement.  When the reader attempts to understand that statement, which may be meaningless to the author, a tacit component is introduced by the reader creating an unintended communication from the author to the reader.

Polanyi, M. (1966). The logic of tacit inference. Philosophy, 41(155), 1-18.
Comment: Very elegantly put, but can you clarify if you mean that art _creates_ communication or if art _is_ communication, or perhaps that the former implies the latter?
Comment: On one hand you're backing up claims with references, but on the other hand you're making questionable inferences with no justification. "If that is the case then any form of explicit communication is rooted in tacit knowledge." why? Lying is a form of communication. Is that also a kind of knowledge?
Comment: @Mossmyr As I see it thinking of Polanyi, art both creates and is communication. The part one can point to as an object is the explicit part. What's tacit allows for understanding of what that art _object_, that explicit part, means.
Answer: I started working at an art school a few months ago, and have since been asking myself what I think counts as art.
The whole definition problem started when our cultural understanding of what art is became divorced from the concept of artisanship -- instead becoming linked to ideas about inspiration, uniqueness and genius (which lead to celebrity artists).
Even in the olden days I imagine, whether a cavemen was good at drawing oxen or whether a sculptor was skilled in making marble busts was up for debate. But now that artworks can be mainly conceptual (should be, according to many), what counts as art is even more complicated to lay down.
Anyone can have their own definition, of what art is and what isn't and what it should be. I too have a certain standard, but I won't bore you with that. Someone wants to call art a form of communication? Sure! Join the club and let's have a beer.
Ironically, the study of human communication has the same problem. I have a masters degree in Communication Science, and from what I remember learning at university, anything can be considered communication. Researchers studied anything from the cultural norms expressed in private letters between migrants and the families they left behind, to long-term effects of television soap operas on society as a whole. Each separate field of research may use a different definition of communication, which is fine. Communication Science is about asking 'what is going on between people communicating' (be it mediated or not, personal, many-to-many or one-to-many), and 'what is the result of all that communicating', and both questions are interesting and hard enough as it is. What truly counts as communication is not very interesting nor very useful as a general question.
Whether art counts as communication is, in my opinion, also a rather useless question. Art can be anything you define it to be. People have been shitting in cans and then had those cans be displayed in museums (see Merda d'artista). People who just put an entire pharmacy in an art gallery (Damian Hirst) have been applauded as exciting, innovative artists. Communication can also be anything you define it to be. Trying to define one as the other may sound interesting, but don't expect to gain any useful knowledge from the exercise.
Comment: Sturgeon's Law is helpful in these situations.
Answer: If we take communication as a mean to transmit information, with information allowed to be something as simple as one's sentiment, and with art having be sensed in some way, even if it is to sense its void, then I fail to see how art can not be communication.
Like other answers brought up, Art is a contested term. Fundamentally, however, it is an expression. An expression carries  information about one's sentiments; showcasing something that is pleasing to the artist, or something that is painful, or just what is. The scratches, etchings, whines and scribbles that may result from a subconscious fragment of one's state of mind are still expression, carrying equally blurred information even if it is just "I exist".
Ultimately, those who create art from being hired to do so are also communicating their understanding of what is being requested, regardless how they feel about it.
Comment: Graffiti on train cars appears to mean basically, "I exist". Not sure about the reason to want to express that.
Answer: Questions

Does art require an emotional state or an idea to be transmitted between two parties?
If so, does the communication have to be intended by the author or can it be incidental?

Added later (to @frankhubeny)

Does art create communication?
Or if art is communication?
Or perhaps that the former implies the latter?

Perhaps best to focus on
@Eliran summarized versions

Is art a form of communication?
What does it communicate exactly?

Here is...
Bob Dylan
Here is an example where message (communication) and art are inextricably linked.
And his Nobel prize citation

For having created new poetic expressions within the great American song tradition.

So the question whether art and the message(in this case pacifism) are linked is only non-trivially a question in the hi-brow «classical» tradition.
And that too only in the western tradition. It would become even easier to demonstrate from other-tradition material but for now I won't cite more art-examples.
Four levels of communication
Indian philosophy traditionally grades vak or vani into 4 gradations.
Vak is roughly speech and vani sound but we could treat them as communication.
The 4 grades or levels are

para
pashyanti
madhyama
vaikhari

Literally they would be

beyond or other
seeing
middle or intermediate
words

For philosophical purposes we could translate these as

transcendent
insight or intuition
mentalese (see Pinker1
The hypothetical language of thought, or representation of concepts and propositions in the brain, in which ideas, including the meanings of words and sentences, are couched
verbiage

A more elaborate explanation of these gradations by Robert Svoboda
Brings us to...
Real communication is communion

The deepest level of communication is not communication, but communion. It is wordless. It is beyond words. It is beyond speech. It is beyond concept. Not that we discover a new unity, but we discover an old unity. My dear brothers and sisters, we are already one. But we imagine we are not. And what we have to recover is our original unity. What we have to be, is what we are.

Fr. Thomas Merton
Some may find the following (copy-paste!) from Gurdjieff helpful.
Subjective and objective art
(Selections from Ouspensky's In search of the miraculous.
G is Gurdjieff)
At the moment it is not yet clear to you," G. once said, "that people living on the
earth can belong to very different levels, although in appearance they look exactly the  same. Just as there are very different levels of men, so there are different levels of art.
Only you do not realize at present that the difference between these levels is far
greater than you might suppose. You take different things on one level, far too near
one another, and you think these different levels are accessible to you.
"I do not call art all that you call art, which is simply mechanical reproduction,
imitation of nature or other people, or simply fantasy, or an attempt to be original.
Real art is something quite different. Among works of art, especially works of ancient  art, you meet with many things you cannot explain and which contain a certain something you do not feel in modem works of art. But as you do not realize what this
difference is you very soon forget it and continue to take everything as one kind of
art. And yet there is an enormous difference between your art and the art of which I
speak. In your art everything is subjective — the artists perception of this or that sensation; the forms in which he tries to express his sensations and the perception of these forms by other people. In one and the same phenomenon one artist may feel one
thing and another artist quite a different thing. One and the same sunset may evoke a feeling of joy in one artist and sadness in another. Two artists may strive to express
exactly the same perceptions by entirely different methods, in different forms; or
entirely different perceptions in the same forms — according to how they were taught,
or contrary to it. And the spectators, listeners, or readers will perceive, not what the artist wished to convey or what he felt, but what the forms in which he expresses his sensations will make them feel by association. Everything is subjective and
everything is accidental, that is to say, based on accidental associations — the impres-
sion of the artist and his 'creation'" (he emphasized the word "creation"), "the
perceptions of the spectators, listeners, or readers.
"In real art there is nothing accidental. It is mathematics. Everything in it can be
calculated, everything can be known beforehand. The artist knows and understands what he wants to convey and his work cannot produce one impression on one man and another impression on another presuming, of course, people on one level. It will always, and with mathematical certainty, produce one and the same impression.
"At the same time the same work of art will produce different impressions on people of different levels. And people of lower levels will never receive from it what people of higher levels receive. This is real, objective art. hnagine some scientific work — a book on asttonomy or chemistry. It is impossible that one person should understand it in one way and another in another way. Everyone who is sufficiently prepared and who is able to read this book will understand what the author means, and precisely as the author means it. An objective work of art is just such a book, except that it affects the emotional and not only the intellectual side of man."
"Do such works of objective art exist at the present day?" I asked. "Of course they
exist," answered G. "The great Sphinx in Egypt is such a work of art, as well as some
historically known works of architecture, certain statues of gods, and many other
things. There are figures of gods and of various mythological beings that can be read like books, only not with the mind but with the emotions, provided they are sufficiently developed. In the course of our travels in Central Asia we found, in the desert at the foot of the Hindu Kush, a strange figure which we thought at first was some ancient god or devil. At first it produced upon us simply the impression of being a curiosity. But after a while we began to feel that this figure contained many things, a
big, complete, and complex system of cosmology. And slowly, step by step, we began to decipher this system. It was in the body of the figure, in its legs, in its arms, in its head, in its eyes, in its ears; everywhere. In the whole statue there was nothing
accidental, nothing without meaning. And gradually we understood the aim of the
people who built this statue. We began to feel their thoughts, their feelings. Some of
us thought that we saw their faces, heard their voices. At all events, we grasped the
meaning of what they wanted to convey to us across thousands of years, and not only
the meaning, but all the feelings and the emotions connected with it as well. That
indeed was art!"

"Men have tried for a long time to invent a universal (philosophic) language," G said. "And in this instance, as in many others, they seek something which has long since been found and try to think of and invent something which has been known and in existence a long time. I said before that there exist not one but three universal languages, to speak more exactly, three degrees. The first degree of this language already makes it possible for people to express their owm thoughts and to understand the thoughts of others in relation to things concerning which ordinary language is powerless."
"In what relation do these languages stand to art?" someone asked. "And does not art itself represent that 'philosophical language' which others seek intellectually?"
I do not know of which art you speak," said G. "There is art and art. You have
doubtless noticed that during our lectures and talks 1 have often been asked various
questions by those present relating to art but I have always avoided talks on this
subject. This was because 1 consider all ordinary talks about art as absolutely
meaningless. People speak of one thing while they imply something quite different
and they have no idea whatever what they are implying. At the same time it is quite
useless to try to explain the real relationship of things to a man who does not know
the A B C about himself, that is to say, about man. We have talked together now for
some time and by now you ought to know this A B C, so that I can perhaps talk to you
now even about art.
"You must first of all remember that there are two kinds of art, one quite different
from the other — objective art and subjective art. All that you know, all that you call art, is subjective art, that is, something that I do not call art at all because it is only objective art that I call art.
"To define what I call objective art is difficult first of all because you ascribe to subjective art the characteristics of objective art, and secondly because when you happen upon objective works of art you take them as being on the same level as subjective works of art.
"I will try to make my idea clear. You say — an artist creates. I say this only in
connection with objective art. In relation to subjective art I say that with him 'it is
created.' You do not differentiate between these, but this is where the whole
difference lies. Further you ascribe to subjective art an invariable action, that is, you expect works of subjective art to have the same reaction on everybody. You think, for instance, that a funeral march should provoke in everyone sad and solemn thoughts and that any dance music, a komarinsky for instance, will provoke happy thoughts.
But in actual fact this is not so at all. Everything depends upon association. If on a day that a great misfortime happens to me I hear some lively tune for the first time this
tune will evoke in me sad and oppressive thoughts for my whole life afterwards. And
if on a day when I am particularly happy I hear a sad tune, this tune will always evoke
happy thoughts. And so with everything else.
"The difference between objective art and subjective art is that in objective art the
artist really does 'create,' that is, he makes what he intended, he puts into his work
whatever ideas and feelings he wants to put into it. And the action of this work upon
men is absolutely definite; they will, of course each according to his own level, receive the same ideas and the same feelings that the artist wanted to transmit to them. There can be nothing accidental either in the creation or in the impressions of objective art.
"In subjective art everything is accidental. The artist, as I have already said, does not create; with him 'it creates itself This means that he is in the power of ideas, thoughts, and moods which he himself does not understand and over which he has no
control whatever. They rule him and they express themselves in one form or another.
And when they have accidentally taken this or that fonn, this form just as accidentally
produces on man this or that action according to his mood, tastes, habits, the nature of the hypnosis under which he lives, and so on. There is nothing invariable; nothing is definite here. In objective art there is nothing indefinite."
"Would not art disappear in being definite in this way?" asked one of us. "And is
not a certain indefiniteness, elusiveness, exactly what distinguishes art from, let us
say, science? If this indefiniteness is taken away, if you take away the fact that the
artist himself does not know what he will obtain or what impression his work will
produce on people, it will then be a 'book' and not art."
"I do not know what you are talking about," said G. "We have different standards: I
measure the merit of art by its consciousness and you measure it by its
unconsciousness. We cannot understand one another. A work of objective art ought to
be a 'book' as you. call it; the only difference is that the artist transmits his ideas not
directly through words or signs or hieroglyphs, but through certain feelings which he excites consciously and in an orderly way, knowing what he is doing and why he does it."
Answer: Yes, if your model of communication is broad in scope. For example, below is an illustration of Roman Jakobson's theory of communication. Here, communication is not merely a message encoded and transmitted from one point to another, but is characterized according to different aspects of the communication process.

Referential (what the message is about)
Aesthetic/poetic (the message for its own sake)
Emotive (information about the sender)
Conative (vocative or imperative addressing of receiver)
Phatic (checking the communication channel working)
Metalingual (about the language itself, checking code working)

Although Jakobson's concern is literature and he refers only to the aspect as aesthetic/poetic that can be related to art, a more contemporary approach could re-interpret this model as every aspect potentially taking part in the communication of art. Art can not only tell a story (1) or be created for its own sake (2), but can also express the artist's inner feelings (3). It can also directly address the viewer (4), explore the medium/materials/technique of artmaking (5), or play with or create a new language (6).
Answer: I mean on a superficial level it's easy to dismiss this idea based on selective definitions of art and communication.
For example you could take the etymological definition of the English word "art" and just translate it to "skillful", then no, being really good at X is not really a form of communication. Even if you argue that the quest for improvement of a skill also creates a "perfect" version of the thing that you strive towards and that this is the expression of an aesthetic, of an idea or a philosophy that you express, you could also just do that in the confines of your own home and never talk about it with anybody thus being an artist without communicating.
So given that the interaction with an other is kinda the minimum requirement of a communication, one would need to answer at least the question as to "whether art can be art without an audience".
So is it just about the process of doing it? The result of having done it? The moment someone else interacts with it (actively, passively, emotionally)? And is it the artist that makes it art or the observer? For example consider ancient pottery, back in the days it might have been a tool for practical usage, 2000 years later and people put it in a museum and call it "art".
And in that latter sense you have at least one way of a conversation, that is you have the creator sending a message and a receiver reacting to it. But even if we assume that we're witnessing an alien species, don't know the language and just observe the interaction then we'd still kinda expect that a communication goes both ways. And even though there are also real life conversations where only one side does the talking, you'd still in those cases have a dedicated audience and the awareness of a communication. While you can imagine art where that is not the case "death of the author"/"found footage" for example.
Though it's quite possible that an active audience member (especially in the age of social media where everything has a comment function), would consider art to be a conversation, even the artist might disagree. Or an artist could think of art as a conversation when they provide society with an interesting problem waiting for their reaction to it, but they just don't. Depending on the definition that is failed communication, unintentional communication or no conversation at all.
"Bearing in mind that the definition of art is disputed, did any philosophers argue that a work requires an emotional state or an idea to be transmitted between two parties for it to be considered a work of 'art'? If so, does the communication have to be intended by the author or can it be incidental?"
Either way "art" would struggle to meet those requirements of a direct, bidirectional exchange of information and emotional states, in a shared language.
Maybe art is better described as a proto-conversation. By which I mean an attempt to create a connection and establish a language in order to later have a conversation.
Like art is both a tool to express something, an attempt to show an example of something that doesn't exist or describe the undescribeable and on the other hand a window into your soul that you leave open for other people. Yet as there is no established language the conversation can be pretty rough and misunderstandings are almost inevitable especially if the communicating parties are separated from each other in space and time and can't agree on a shared list of definitions.
Though even if the artist has no "mission" or "message" they nonetheless transport a lot of information even if the audience is eavesdropping rather than being talked to?
So there's plenty of possibilities to dismiss this picture and to establish more narrow definitions of communication where art doesn't fit, but one can also kinda see where people are going with that.
Answer: Art has been a form of communication for centuries. You see very well developed art forms in ancient India. Some of them still survive. They have complex hand and feet gestures synced to different musical instruments. If you watch a classical Indian dance performance you will be overwhelmed with emotion. This art form is very detailed and sophisticated. Dance is an art form which communicates with the audience in real time, providing a profound and exhilarating experience.
For those who are unaware of the complexity of Indian Classical Dances, check out this short description along with illustration. https://exampariksha.com/important-folk-classical-dances-of-india-general-awareness-study-material-notes/
Comment: Artists themselves mainly contend that they are intentionally sending some sort of message. They are often cryptic or coy about what that message is. Art critics spend much of their time trying to decipher those messages. But this question as to whether art is a form of communication is not a matter of opinion, it is undeniably a matter of fact. The matter of what an artist is trying to communicate, now there's the rub! CMS
Comment: How does this answer the question? You say "art has been a form of communication for centuries", but without any sources to back that up, it's just your opinion. Also, these "well developed art forms" are presumably static, representing dance, after which you delve deeper into dance as another art form, which communicates, again without giving argumentation. If the linked article holds answers to these questions, could you quote the relevant passages?

Is art a form of communication?


Why is IPv6 not backward compatible with IPv4?

Question: Also, how does it affect our websites? Do we need to shift all IPv4 websites to IPv6 or both?
Answer: There should be no need to shift existing websites onto IPv6 for a long time. IPv4 will keep running for years yet. There will be a process where new services begin to use IPv6 instead of IPv4. The two systems will co-exist side by side. To the end user, assuming they have their software up to date, they should notice no difference. If you want to test whither your PC can cope with IPv6, just go to this page: ipv6test.google.com
As IPv4 addresses run out, there will not be a sudden end. Rather the price to obtain an IPv4 will increase and IPv6 will begin to look attractive as an alternative.
8 June, 2011 was IPv6 day. Many major sites including Google, Facebook, Yahoo! and others turned their servers to IPv6 for one day. The internet continued as normal that day.
If you are running your own web server, you will have to read up some details on IPv6 in order to use it, when the time comes. There are a few tweaks that will need to be made by the admin to the server. However, if you, like most web site owners, purchase your hosting from a web hosting provider, then you needn't do anything. The service provider will take care of everything.
Why is IPv6 not backward compatible? Well IPv6 is more than just a change in the IP number though that is a significant part of it. There are a load of other changes to the function of the protocol which should enhance security and speed while simplifying many operations. Have a look at this article on IPv4-IPv6 Compatibility
Answer: IPv6 is mostly about the "plumbing" between your server and the user. The various parts of that plumbing may or may not be IPv6 compatible. Even if you make sure the network from your server to your ISP is your ISP may not support it. On the other hand, it's worth making sure your webserver software (Apache or IIS say) supports it (Apache v2.0 and upwards does, IIS 6.0 and upwards does), and your network equipment.
The main way that it would stop things working is when someone registers a domain and there are no IPv4 IP addresses available for the hosting company to use, so they only get an IPv6 IP address. Then it will only be accessible to people who have IPv6 all the way between them and the server.
Although the last lot of IPv4 addresses have been given to the people who give them out, they haven't all been given out. Also, if it really looks like it's getting short people may release unused addresses.
Comment: IP addresses are not allocated when people register a domain. Hundreds or thousands of domains can be hosted on a single IP address.
Comment: True, I've oversimplified it. I've now amended that sentence. In fact whilst hosting companies can squeeze sites onto as many servers as possible, using as few IP addresses as possible we'll probably be OK for years to come.


Installation path for root

Question: My understanding of paths is that ~/.jungledisk/ means the path is relative to the current user.  If that's true, if I installed this as root, where did it go?
Answer: Probably the same, unless the installation special-cases root, in which case who knows.
Comment: But root doesn't have a `/home/` folder, are you saying it would go to `/`?
Comment: @Webnet: No, it would go to `~root`.
Comment: @Webnet, Root's home directory is typically /root/ on Linux boxes.
Answer: I'm not sure: in case you install as root, that folder could be also created under /root, I mean, /root/.jungledisk, and its permission and owner would be unavailable for other users.
Anyway, when some program asks you to "make install" as root, it does knowing that the installation will copy binaries on folders that are only writable by root. But users will be able to use that utilities (read and execute them, not write/edit/delete them), so there should be no problem.
Don't know if I 've understood the problem, but there it goes :)
Answer: "~" is magically expanded to the actual home directory of the following user.  You can find out what root's (or any user's) home directory like this:
echo ~root

Installation path for root


Graph Invariants and Statistical Mechanics

Question: Many intuitive knot invariants including Jones' polynomial are inspired by statistical mechanics. Further profound connections have been explored between knot theory and statistical mechanics. I was looking if similar connection have been found for graph invariants. I am interested to know if any attempts have been made form statistical physics community to solve graph isomorphism problem. Since both knot problem and graph isomorphism are problem about testing structural equivalence there might be connection between them.
Comment: similar question was posted here http://cstheory.stackexchange.com/questions/12786/approaches-to-gi-inspired-by-knot-problem#comment36561_12786
Answer: Efficient graph isomorphism testing requires very simple invariants, and most graphs can be distinguished with very simple counts (number of vertices, distributions of degrees of vertices, edges, etc.) In contrast, distinguishing knots is something much more involved. Thus I think that there are no relations between graph isomorphism and statistical mechanics.
Answer: Polynomial invariants like the Tutte polynomial can be realised as the partition function of a certain spin-model on the graph. Questions about zeros of this Tutte polynomial are related to the existence of phase transitions, but beyond this, I think that the questions asked about these objects by physicists and mathematicians are very different.


Vegan egg nog for the holidays?

Question: With the holidays coming up this question seems relevant, so here it goes, would it be possible to make a vegan egg nog?
Comment: What characteristics of egg nog are you trying to retain -- general flavor, mouthfeel, etc.?
Comment: General flavor mostly as the question is for the benefit of my stepsister who's a vegetarian.
Comment: @AbrahamRay I see that the question asks about the vegan egg nog, but if this is for your stepsister, as a vegetarian, she probably won't have much trouble with eggs. :)
Answer: Traditional egg nog uses eggs, dairy, sugar, booze, and nutmeg. All of these are actually (lacto-ovo) vegetarian ingredients.
If you want to make a fully vegan "egg" nog, eggs and dairy can't be used. The good news, though, is that those aren't the primary flavor characteristics of the drink! I don't get nostalgic about drinking raw eggs, I'm interested in the nutmeg and sweetness -- and you can still include liquor, sugar, and nutmeg.
There are a lot of options available for replacing that "creamy" base of eggs and cream: non-dairy milks, tofu, cashew cream, and so on. (If your traditional egg nog is one that includes a foamy top layer, find a vegan whipped cream alternative.)
One of my personal favorite versions is Tori Avey's Veggnog, but I'd encourage you to search and try a few different options.
Comment: In that case I recommend rum extract; I do find it to be a helpful flavor (I used it to make non-alcoholic nog when pregnant!)
Comment: Personally I prefer the non-alcoholic version of egg nog myself, but that's just me.
Comment: When I checked out the veggnog recipe I thought it looked great!
Comment: Hope your stepsister likes it too! :)

Vegan egg nog for the holidays?


What is the best method to being able to sing again?

Question: I used to be able to sing and loved to with all my heart but after having neck surgery in 2007 it caused problems with the one muscle that effects the vocal cord. I've tried many times over the years to sing and I get like a charlie horse in my neck and causes severe pain. I want to be able to sing again. I was self taught so I don't know all the vocal lingo. It was the one gift that was taken from me that hurts the most. Loved singing songs by Whitney Houston, Patsy Cline and church music. It kills me every time I try and receive nothing but pain. I even get jealous of my daughter, who like me, has the gift of singing. I would never tell her though. I continue to help her the best I can. Any help would be greatly appreciated as I'm not ready to admit this is over for me.
Comment: Throat musculature is often such a fickle thing that I would hesitate to even recommend anything. Have you spoken with a doctor?
Comment: I talked to about it years ago and she had put me on a muscle relaxer flexeral but it wasn't enough. I had to drop out of choir.
Answer: can't you even sing softly?
if you can talk, you can probably sing softly.
be content with that.  work your way back up the volume scale slowly.  if there's no pain, keep going.  If there is pain, back off and just be happy with where you're at.
Answer: Please do not take the adivce of random people on the internet on this. You need to get a properly qualified medical opinion from a doctor who's actually examined you (possibly the surgeon who operated on you?) and, if they say it's safe for you to do so, then see a vocal coach or speech therapist with specific experience in this area, not just any old singing teacher.
As Stephen says, if you can talk then you can probably still sing, but if there is any pain at all when singing then something is not right, and nobody can diagnose the problem at a distance. Whatever you do, do not be tempted to push through the pain.
Comment: I can talk just fine but I can't even hum a song. It's really depressing and hard to be happy with what I got when I can't even manage to hum a tune and used to being able to sing any song I liked. I love music and I loved to sing. To have that gift ripped away is not something I can be happy with. I used to sing to my kids and now have a grandbaby coming and I want to be able to sing to him or her.
Comment: That must be very difficult for you. Do seek out medical advice - your general practitioner should be able to point you in the right direction. If you can talk then there's reason to hope that you may be able to learn to sing again with help from an experienced teacher, but there are some people who do lose their singing voices altogether and that must take some adjusting to. Don't give up hope until you've explored all the possibilities, and best of luck with it!


facebook allow access dialog

Question: I've developed a facebook app (type: iframe) that will load within a fan page's tab.  On that tab I have a link (code below) that goes to a page outside of the facebook domain, and it opens in a new window.  My link has the "requirelogin=1" attribute so I can pop up facebook's require access dialog when the user clicks the link.
My problem is after the user clicks "the Allow" button in the "allow access" dialog, my link loads in the same window instead of opening a new one.  Has anyone come across this problem or have a suggestion to get my link to open in a new window after the user clicks the "Allow" button?  One solution I tried was to set my href to an interim page which would call window.open to pop my url and then also reload the fan page tab that I was currently on, but that seems like a really hacky solution.  Any additional ideas would be appreciated.
Answer: Try this, you can force the link that opens the dialog to do so in a new window with target :
Logging with Facebook

Hope that helps !

facebook allow access dialog


Working with File Geodatabase in QGIS for MAC OSX?

Question: I understand there are programs like OSGeo4W that allow windows users to work with Esri File Geodatabases, but is there something similar for Mac OSX 10.6?
Comment: You are going to need to give us more info. What steps have you followed?
Answer: OSGeo4W is, well, OSGeo "for Windows", so it is not what you are looking for.
I have not done it myself, but other people have, so I know it works.
I would recommend you

get the KyngChaos binaries for QGIS
compile the OGR FileGDB driver (which will produce a "dylib" file on the Mac)
drop the dylib on the plugins directory of GDAL on the Mac. I believe this directory is /Library/Application Support/GDAL/PlugIns/$(GDALVER) according to the Kyngchaos documentation (very last line).

For #2, you will need to download the exact version of GDAL that is used by the Kyngchaos build you have. Instructions on how to create the dylib for filegdb can be found on the net.
I realize this is not for the faint of heart, it would be nice if somebody created a brew recipe for this. hint hint, anyone?
Update
There is a much easier way now using Homebrew:

Install Homebrew

Go to the ESRI site and download the FileGDB API for Mac. After extracting, you will notice that there is a lib folder and an include folder.

Copy the contents of the include folder to /usr/local/include and the lib folder to /usr/local/lib (this is basically "installing" the FileGDB API in your system)

Install gdal using brew (pass the with-unsupported flag).
brew install gdal --with-unsupported

That's it!
Optionally, if you want QGIS, install it using this Homebrew Science recipe.
Comment: You can now download the FGDB API without logging in from this page: http://www.esri.com/apps/products/download/#File_Geodatabase_API_1.3
Comment: the link to the arcgis website somehow requires login and password...
Comment: @donschoe that is ESRI's requirement. You can create an ESRI global account in the link below the login page - it is free
Comment: @scw that link requires me to log in after choosing my package.
Comment: I was able to get this to work, but I had to install the kyngchaos FGDB plugin from http://www.kyngchaos.com/software/frameworks#gdal_complete.
Answer: From your problem description, it seems ok to just get the data out somehow.
Try GDB Flee, an online tool to convert GDBs into open formats.
Comment: The GDB github link has turned to be an invalid one : 503 Service Error. Could you update it?
Answer: First, you'll have to compile GDAL with ESRI FileGDB support. Once you've done that, you can then use this build of GDAL in a KyngChaos build of QGIS. On your terminal:
<code># save your current GDAL so you can put it back if you want
cp /Library/Frameworks/GDAL.framework/Versions/1.8/GDAL /Library/Frameworks/GDAL.framework/Versions/1.8/GDAL_orig

# symlink the custom GDAL build to the place QGIS looks
rm /Library/Frameworks/GDAL.framework/Versions/1.8/GDAL
ln -s ~/local/lib/libgdal.dylib /Library/Frameworks/GDAL.framework/Versions/1.8/GDAL
</code>
Thanks to @Ragi for the instructions to the Github gist.
Answer: OSGeo4W reads GDBs using GDAL/OGR which you can install on OS X via Macports or Kygchaos's binary distribution.
Answer: .gdb is the proprietary format for ESRI's geodatabases. For more information on how to access gdb look here
File Geodatabase (*.gdb) support in QGIS?
Comment: I guess I should of also added that I'm using a MAC so this plug-in won't work for me. Also, if you look at the data I listed above, a WHOLE bunch of files download. I'm not even sure what I'm looking at. Which one is the right one?
Comment: gdb is a geo-database. ESRI is using a modified ms-access schema to store and validate geographic data. The bunch of data (I assume inside a folder that ends in .gdb) is just tables that mean to work together somehow. Since your software cannot handle the file/folder you see all those files.
Comment: NYC open data and they using closed formats... It's open only for those who can buy arcgis
Comment: RATS! It can't be easy all the time!
Comment: @MikeGuillen Please indicate your OS next time.
Answer: I finally got file geodatabases working on QGIS for Mac. Using the instructions on the readme file of Kyngchaos FileGDB plugin:
download and install FileGDB plugin from http://www.kyngchaos.com/software/frameworks#gdal_complete
download and unzip fileGDB API from resources.arcgis.com/content/geodatabases/10.0/file-gdb-api
Move the 2 .dylib files from the lib folder of the fileGDB API to the folder /Library/Application Support/GDAL/1.9/Libraries
start QGIS, add vector layer, select the source type as directory and ESRI FileGDB should appear right away.
Comment: This didn't work for me. I followed the instructions but ESRI FileGDB doesn't show up. I'm using Mac OS 10.8. I've tried with GDAL v1.9 and v1.10. Any suggestions?
Comment: Are you sure you're adding a directory instead of a file? In order to add a gdb you need to choose "directory" when selecting the type of vector file to be added.


What does Anna mean when she says that she lost her whistle 133 days ago?

Question: What does Anna mean when she says that she lost her whistle 133 days ago in Prisoners? It just seems too specific coming from a child. And what does Mrs. Dover whisper to everyone right after it?
Answer: Sorry if this is a partial answer (I'll delete it if you think it's not up to standard), but for what it's worth, the script eludicates what Grace said:

ANNA: The emergency whistle Daddy gave me. I lost it... (thinking) Hundred and thirty-three days ago.
GRACE: She's just like her father.

So Anna remembering the exact day is supposed to demonstrate her similarity to her father. However, I'm not quite sure how. Maybe because he's good with numbers as a carpenter? Has a good memory? Notes certain things others don't or can't let them go? (Then again, I don't remember much of this film, so maybe commenters can enlighten me on how this is also one of Keller's character traits.)
Comment: I agree with this. Its part of her characterization. Keller is a very prepared and precise individual and it would make sense that he would have a child with some similar traits.
Comment: Yeah. This might as well be  the correct explanation. Makes sense. Thanks @Walt
Comment: I just thought of something else too. The loss of her whistle might have meant to serve as a foreshadow of Keller losing Anna. Maybe I'm overthinking it though.
Comment: Her mom says "she's just like her father" because the daughter's mention of the exact number of days suggests she has inherited her dad's anxious and obsessive-compulsive nature (evidenced by his survivalist fears and the organization of his basement).
Answer: I found this answer on Yahoo:

Q 1. Why was there (coincidentally) a whistle down under the trans am?
  Did Anna drop it there "133 days" ago?
A 1. The girls were initially kept in that hole in the ground under
  the Trans-Am while the police searched the aunt's house for the girls.
  Anna must have dropped her pink whistle there. Her mother later bought
  her a new red whistle to replace the one lost. Joy and Anna had made
  it to Anna's house and Joy had found the first whistle so the girls
  were abducted on route back to the Birch's house.

My guess is that at some point, as most prisoners do, she began counting days in captivity.
Comment: No. You didn't understand. She said that she lost her whistle before the kidnapping, during the Thanksgiving dinner.


How to avoid clipping when explicitly adding audio tracks?

Question: When two or more audio tracks are simply "added" together, they may peak at the same time, causing the resulting "sum" track to be clipped.  I am looking for an algorithm or technique to bring the "sum" track back within limits, without causing too much distortion.  Are there any standard ways of doing this?  Please note that I'm not looking for a solution in a specific audio tool like audacity; rather, I want to understand how such tools implement track mixing.
Comment: Related Question: http://avp.stackexchange.com/questions/1599/0db-mono-vs-0db-stereo
Answer: I believe Zettt has nailed an answer (nice one Zettt). I want to extend this to a bigger picture.
There may be an algorithm but I don't know of it specifically as an equation. This is all about mixing sound tracks like you are a great chef cooking up an unbelievable dish. Start with the finest ingredients, in this case sounds you have already recorded that are clear, and do not clip at all. Your goal is to mix all the ingredients so you can taste each one without it overwhelming the others or losing its identity. This is why your ears like your taste buds will be the most important guide. Consider how a music arranger puts together a score for an orchestra. Take into account how the timbre of each instrument will have both an individual composite of harmonics and how these change over the entire instrument's range.
For instance if I was mixing violins and a triangle, I already know that a triangle has a very odd set of harmonics, and I won't have to give that track much gain at all for me to hear it clearly. You rarely see a percussionist hitting a triangle very hard because its tone is so differently constructed that a slight hit will cut through the rest of the orchestra very easily.
Mixing is not about adding one thing on top of each other, it's about balancing a blend that you can hear everything in the mix. Yes, you have to keep the gain under 0 dB, you can not have any clipping, not any or else you just burnt your dish.
You can think of the spectra envelope of each instrument as a guide but allow for your ear to tell you when it's right.
What controls do you have when you are mixing tracks?
For one you have the gain of each track, then you have where it lives in the stereo field, is it best in the center? 15% to the right, 20% to the left?
How you control the way an overall sound envelope is another factor, does it have a fast attack, does it fade away, do you want to have it ride in the distance, or bring it up front?
Another thing to think about is the depth, how much reverb if any, this will also color the sound. Notice as you add reverb you loose some highs and it sounds like it's further away, is that what you want?
Summary:
Mixing sound is like making a great meal, you start with the best ingredients and allow each to stand out without overwhelming the others or getting lost. Be aware of your instruments spectra, envelopes, and how all this changes over the entire range. Be aware of what controls you do have and how these can be best set for your desired results.
Finally, don't be afraid to try new things, take risks, you can always change it back before you make your master.
Comment: Your answer suggests that even if there is a simple algorithm to limit or eliminate clipping, it will produce poor results.  The expertise of a human expert will always be needed to deal with all the subtleties.
Answer: Two uncorrelated signals sum up by about 3dB per additional signal (I couldn't find an English reference for this. Maybe someone else will.). To keep your sum from clipping, just turn down the volume of the individual tracks.
Comment: I think [this](http://en.wikipedia.org/wiki/Pan_law) is pretty close to what you are looking for.  (Found in [this](http://avp.stackexchange.com/a/1600/126) answer by @MarkHeath)
Comment: Good reference Friend of George, thank you.
Comment: @FriendOfGeorge Yes, that looks very good. Thanks!
Answer: A digital signal always has a maximum level. If summing two tracks to one signal drives the level above this point, it will clip.
Most DAW tools I know of don't have any kind of fix for this. They will happily let you drive a signal to clipping, and leave the decisions of how to deal with this to you.
There are a few standard techniques for getting around this:

Turn the tracks down before they clip.
Use a dynamic range compressor on one or more individual tracks. What this does is automatically reduce the level of a signal by a percentage, but only when it's above a certain loudness level. Choose this level (the "threshold" control) and the ratio in such a way as to avoid clipping.
Use a limiter on the resultant signal before it hits the clipping stage. A limiter is just a more extreme compressor, and I tend to use them more as a 'safety net' when I'm not sure how loud a signal is going to be driven.

Keep in mind that compression and limiting do modify your signal, and therefore are distortions, albeit usually mild ones. Extremely compressed signals tend to sound distorted.
When you describe an algorithm to automatically reduce peaking sounds, this is the sort of thing I think of.
Comment: Thanks for the links to wikipedia, they're very instructive.  You say that dynamic range compression reduces the signal by a percentage when it gets too loud.  Do I understand correctly that this won't stop clipping in all cases?
Comment: That's exactly right. It's still possible to drive the signal before the compressor hard enough that it clips again at the output. The only exception I'm aware of is a 'brickwall' limiter, which (as I understand it) has an infinite ratio, and therefore a maximum output level.


Need to hard reset Dlink router once a week

Question: I am having a Dlink DIR 655 router at the home. Once a week randomly, I see that my connection becomes weak and faulty. I have to go and do a hard-reset of the router (switch off and switch on), so that my wireless connection becomes usable again. Could this problem be with a bad router product or can I do something to have reliable wireless connection through out? If you have faced this problem how have you dealt with?
Comment: I'm not trying to be a troll or anything, but I had to do the exact same thing with my DIR-655 (latest firmware, tweaked settings, etc...).  I was so frustrated that I just replaced the router with one that supported OpenWRT.  I only noticed connection issues over wireless, not over ethernet.
Comment: Which connect becomes weak and fault -- the connection between your machines and your router or the connection between your router and the Internet?
Answer: If you've already updated your firmware and there was no improvement, you might want to either return it, or, if it's already out of warranty/return period, check the in browser administration page. There should be a button to reset the router. If pressing that button fixes the problem by resetting the router, then you'll have a way to automate it.
I've had sort of a similar problem and the way I solved it way like this: I used developer tools within Firefox (you could also use Wireshark or most other browsers) to check the POST data that is sent when you click it. Once you have that, you can easily replicate this by using cronjobs/scheduled tasks and curl.
I use it on a Windows server to run once a day and basically it looks like this:
<code>curl.exe --head -d "POST_DATA_HERE" username:email@example.com/apply.cgi
</code>
Obviously you'll need to find what exactly (if anything) is sent to your router, and if the control panel reset is even sufficient.
Answer: Check the ventilation around the router: make sure it is getting enough air circulation to not overheat.  Many network devices operate on the edge of their thermal limits and all it takes is a bit of dust, being covered by papers, or being shoved under a shelf to push them over the edge.
Poor behavior after running for a few days (or even just a few hours), followed by good behavior after a restart is a classic symptom of heat damage.  It is also a symptom of a buggy router, so check the firmware too.  Unfortunately, once the components have been damaged by heat they may not recover even with cooling.  So you might need to replace it anyway.  Just make sure all your network devices are well ventilated.
Comment: That's a helpful response. I should take care of that.
Answer: First, update your firmware. If this does not address this, this would not surprise me. DLink is pretty bad for quality assurance of hardware. I've seen unreasonable lack of connectivity and proper functionality from their devices in multiple situations. If this does not get resolved you should consider an Asus or Linksys router. Now adays getting one with built in gigabit switching is really the way to go, it costs a bit more, but gigabit switching is so much better than 10/100, it's like night and day.
Example: http://www.newegg.com/Product/Product.aspx?Item=N82E16833320038
Answer: To be honest, DLink doesn't have a very good reputation on building high quality products. Nevertheless I have seen cases that NAT in a router is causing memory leaks and performance degradation over time.
Sometimes a firmware update can fix this, sometimes it might be better to buy a different product.
These kind of things are hard to diagnose if you don't have full access to the firmware and/or router, but if you get problems after a lot of traffic using torrent clients (to name a classic example) you might be having that issue. (Torrent clients are making tons of connections to a lot of different ports and therefore consume a lot of router resources.)
Make sure the router isn't overheating, make sure you don't have a neighbor who's transmitting on the same wireless channel as you do (use a program like Insidder to check that.) and with all of this you probably can tell what is causing your specific issue.
Good luck and hope this helps!
Answer: You might want to look at www.dd-wrt.com. This is an open source router OS firmware that can be installed on many different brands of routers. You might look to see if this kind of option is possible, and if you router will support installing it.
Comment: The DIR 655 cannot run dd-wrt because it uses a Ubicom processor.
Comment: Yepper...http://www.dd-wrt.com/wiki/index.php/Supported_Devices#D-Link


how to play games using bumblebee + wine 1.5

Question: I recently moved to ubuntu after seeing "it supports windows games".
Since i have a dual graphics card: Intel 4000 and nvidia 630m, i installed bumblebee to make use of the graphics cards efficiently.
'optirun glxspheres' or any program runs perfect.
Now, the problem is i need to play "NEED FOR SPEED - MOST WANTED (2005)". I have installed wine 1.5.30 and playonlinux. But, i can't play the game.
Also i just tried opening the speed.exe file and game worked fine! Now, my problem is, it uses the intel 4000 graphics. I need to make use of nvidia 630m. Otherwise, spending money on nvidia 630m is a waste right?
So, can you please give me a step-by-step guide to help me sort this problem?
Thank you :)
Comment: I have similar problem, can't run Civilization V with optirun. It works well without optirun in internal Graphic Card. And optirun works well with glxspheres
Answer: cd to the game dir, then try
optirun wine speed.exe

or
optirun bash
wine speed.exe


What is Vibhava Tanha?

Question: What is Vibhava Tanha?
What is the destination (rebirth) of a person with Vibhaba Tanha?
Is the view non-existence considered Vibhava Tanha?
What is the Sutta reference relating to this teaching?
Why the desire for Nibbana is not considered Vibhava Tanha?
Answer: Vibhava Tanha is simply the craving for an experience to go away or end. Ex: When you are meditating, if pain arises in the legs or back and if you are unmindful(ignorant), disliking will arise. This results in wanting the pain to go away. This wanting is Vibhava Tanha.
On a broader scale,  craving for annihilation after death is also Vibhava Tanha. But the view that everything ends after death is not the craving itself. That comes under Micca Dhitti. This view can give rise to Vibhava Tanha.
Craving for Nibbana can be either Bhava Tanha or Vibhava Tanha depending on your false view of Nibbana. If you think of it as a status to achieve or a land/heaven to enter or a state of bliss, those false views can cause Bhava Tanha. If you think of it as nothingness or emptiness or end of a being, those false views can cause Vibhava Tanha.
But just like how the suffering of pain does not end by craving for it to end, Nibbana(end of all suffering) cannot be reached by craving for it. When pain arises in the body, if you practice mindfulness instead of wishing for it to go away, the suffering will stop regardless of if the pain is still there or not. This is a mild realization of the Four Noble Truths. When this realization becomes matured and all-encompassing, all suffering will cease.
Destination of Vibhava Tanha is obviously a lower realm of existence or a state of misery.
Comment: You are doing it again :)
Comment: craving for annihilation after death is not Vibhava Tanha. In this context, Vibhava Tanha.is simply the self craving for the self to die or be annihilated. The teaching of annihilation in the suttas in unrelated to life after death. It is merely a self-view.
Comment: It is! Read the Satipatthana sutta I've linked in my answer
Comment: Whatever you post is wrong view about annihilationism. annihilationism is defined in DN 1 and Iti 49 as the view that a "self" ends at death. It is a self-view.
Comment: Right back at you :)
Comment: No. You are opposing the suttas and not me. DN1 and Iti 49 literally refute your personal ideas. It is "right back at the Buddha".
Comment: I'm not opposing the Suttas. I'm opposing your misinterpretations. I thought we've had this argument many times before. I guess you like going around in circles :)
Comment: Sorry but the suttas are literal. They say annihilationism is a "self".
Answer:
Bhava tanha (craving to become) -- we want  to  be something,
for example,
"fat person want to become thin person"
Vibhava tanha (craving to become not) -- we don't want to be something,
for example,
"skinny  person don't want be thin"

"Becoming craving" is self-denial, "not-becoming craving" is also self-denial --
both suffer in this craving.
Answer: The destination (rebirth) of a person with Vibhaba Tanha is anger, frustration, stress & unhappiness; such as, for example, wanting to not be exposed to reading SarathW's posts but not being able to avoid them. Vibhava Tanha is egoism; as described in Iti 49:

How, bhikkhus, do some overreach? Now some are troubled, ashamed, and disgusted by this very same being and they rejoice in (the idea of)
  non-being, asserting: 'In as much as this self, good sirs, when the
  body perishes at death, is annihilated and destroyed and does not
  exist after death—this is peaceful, this is excellent, this is
  reality!' Thus, bhikkhus, do some overreach.

Aspiration for Nibbana is not considered Vibhava Tanha because there is no egoism.

What is Vibhava Tanha?


SWI-Prolog CGI cgi_get_form(Arguments) web hidden form

Question: I have a problem passing the input type="hidden" form with the CGI library of SWI-Prolog. Specifically I do:
<form id="frmCGIPrologIni" name="frmCGIPrologIni" method="post" action="http://localhost/cgi-bin/x.pl">
<input type="hidden" name="initial" value="ini" /> <input class="submit" type="submit" value="Start" />
</form>
when the program x.pl calls cgi_get_form(Arguments) Arguments should be a list of Name(Value) terms, i,e: [Name, Value], so it should be [initial(ini)].
but when I use this it says: ERROR: =../2: Arguments are not sufficiently instantiated
print_args([]).
print_args([F|T]) :- % with Arguments
    F =.. [Name, Value], % and should continue doing things

I've tried to print it manually with write(Arguments) and what I get is: _L160, and printing the first element is: _G472 and write_canonical(Arguments) returns: '.'(_,_)
I've tried also using the method="get" just for checking it and it prints the URI correctly http://localhost/cgi-bin/x.pl?initial=ini so I guess is not a problem of submitting but of handling with cgi_get_form(Arguments).
The first time 'http://localhost/cgi-bin/x.pl' runs I do:
cgi_get_form(Arguments),

(Arguments = []) ->
(
format('
Print this as the index.
~n', []),
) ; true, % and it works well because there are no Arguments the first time

write('
'), write(Arguments), write('
'), nl, % and print other things

The problem is the second time. This time calling the same program there are Arguments so it doesn't print the message, up to here everything is fine. Then goes through true and continues. That's when I try to write(Arguments) with the results explained before (_L160). And the results should be the data passed by the form.
any thoughts on what is the problem?
Answer: Have you tried
print_args([F|T]) :- % with Arguments
    F =.. [Name | Value], % and should continue doing things


Algorithm to decide if ideal is principal

Question: Suppose $R = \mathbb{Q}[x_1, ..., x_n]/I$, and $J \subset R$ is a given height one ideal. Is there a quick algorithm one could write to determine if $J$ is a principal ideal or necessarily not principal? Is it not possible to do this with Groebner bases?
Comment: Various computer algebra systems have the ability to trim generators of an ideal (or module).  I'm not sure exactly what this does though.  http://www.math.uiuc.edu/Macaulay2/doc/Macaulay2-1.4/share/doc/Macaulay2/Macaulay2Doc/html/_trim.html
Answer: In the graded situation the concept of "minimal generators" is well-defined.  Just think about the minimal generators as part of the minimal free resolution.  Their number is the first total Betti number and those can be computed with Gröbner bases.  Macaulay2 has the command mingens which does it directly.
I don't know how to do it in the non-graded situation since I think the concept of minimal generators of an ideal is not really well-defined.  Maybe principal vs. non-principal can be decided, though.
Comment: For what it's worth, this question inspired https://groups.google.com/d/msg/macaulay2/_3ECYzarTZo/o06fW_-E3SgJ
Answer: Locally principal
At least in height-1 ideal case, in a normal domain (or at least G1+S2 domain), the following should let you know whether the ideal is locally principal.
Let $J$ be the ideal in question and let $J_2$ be another ideal isomorphic to $Hom_R(J, R)$ (which you can do in a number of ways, say by forming a colon or by embedding the module back into R).
Then $J\cdot J_2$ is an ideal.  If $J$ is locally principal, it corresponds to a Cartier divisor $D$.  Then $J_2$ corresponds to $-D$.  It's a fact (first pointed out to me by Tommaso de Fernex) that $D$ is Cartier if and only if
$$O(D) \cdot O(-D) = J\cdot J_2 = \langle g \rangle$$
is principal.
That doesn't help...
But you say, this doesn't help us at all.  All I've done is give you  another ideal we need to check whether or not it is principal!
The point however, is that we know that the reflexification of $I\cdot J$ is principal!  (Recall reflexification just means applying $Hom(\bullet, R)$ twice, Macaulay2 can do this for instance).  Also remember that locally principal ideals are always reflexive.
On the other hand $J \cdot J_2$ agrees in codimension 1 with its reflexification (since reflexification won't change anything in codimension 1 for a normal domain).
It follows that $J \cdot J_2$ is principal if and only if $J\cdot J_2$ is reflexive.
Proposition: Hence $J$ is locally principal if and only if $J \cdot J_2$ is reflexive.
Perhaps its worth noting that you can also use this to identify the locus where $J$ is not locally principal.  If $L$ is the reflexification of $J \cdot J_2$, then compute the
$$\text{Ann}_R(L/(J \cdot J_2)).$$
That is just the locus where $J$ is not locally principal.


Can you report cheaters on online Mario Kart Wii

Question: It seems like the number of annoying cheater on online Mario Kart Wii is increasing. Yesterday I had to reconnect three times before I was put in a group with normal people. Is there any way I can report the usernames or something to Nintendo so that they can do something about it?
Comment: They're getting unlimited powerups and sometimes win without racing. If someone in the group has over 9500 points that's usually a good hint that it is not going to be a fun game...
Comment: @AnthonyBlake Why would you not want to dominate the leaderboards of a game geared towards 15 year olds by cheating? Sounds like a good idea to me.
Comment: how where they cheating? I have never seen this!
Comment: wow. I assume they are playing on a modded game/console. how pointless.
Answer: Instructions

Identify cheaters early on in the game, if possible. Cheaters often have absurd win and loss records, i.e. 100 wins and no losses. They usually will have hacked the game to give them use of unlimited items. For example, if you are hit with a blue shell early in the race and no one has had time to even reach the first item box, you're probably dealing with a cheater.
Quit out of matches against cheaters. If you're able to identify a cheater before the match starts by looking at his win/loss record, then quit out before the match starts. If you quit out before the match starts you won't receive a loss. If the match has already started, quit out anyway. Attempting to race against cheaters at all rewards their behavior.
Report the problem to Nintendo. Although there isn't any official way to deal with cheating in Mario Kart, i.e. by banning the hackers, the Nintendo Tech Support Forum suggests that you fill out an online customer service form so Nintendo can investigate. Fill out all the pertinent information that you can remember about the match such as method of cheating and the player's name. A link to the form is available in the Resources section.

Source
And HERE is a link for a Nintento form.
Comment: You can't see opponents' win/loss ratios in MKWii, only VR/BR.
Comment: This sounds like an okay plan.. I was looking for a more constructive solution, but since there apparently is none, I'm going to accept this answer. Thanks.
Comment: Wow reading this makes me think Nintendo is still way behind in terms of online gaming. I just don't understand how this can happen on any closed proprietary hardware platform. It's not like this is PC Gaming.
Comment: Go to the [CHAT](http://chat.stackexchange.com/) best way to talk about it. But, I love Nintendo, but ... They make a good game and drain it so much... (no, they didn't only one game, but the meaning is that they focus on the main games without new ones). It's almost the same thing over and over again. better graphics, "new story", same idea, same characters (maybe one or two new). Microsoft and Sony are WAY ahead in all those factors and they have great titles too.
Answer: Nintendo is normally good at keeping it's online free of hackers. If the problem persists I suggest contacting Nintendo's customer support.


Kill Bill colour changes to Black and White

Question: In the movie Kill Bill, why does the colour keep shifting from standard colour to black and white? Is it to keep the gross levels down?
Comment: I thought that they ran out of fake blood, so they used something with a different color and made the scene black and white so you wont notice.
Comment: or it can be her vision of how she see's bc she got shot in the head & lived. has its perks doesn't it ?
Answer: Kill Bill is basically a homage to dozens of films from the past, which were generally shown in black & white on television to cut down on the gore. The same happened to Kill Bill to be able to achieve an R rating and be released in theatres.
IMDB's trivia section confirms this:

The black and white photography is ultimately an homage to '70s and '80s US television airings of kung fu movies. Black and white (as well as black and red), were used to conceal the shedding of blood from television censors. Originally, no black and white photographic effects were going to be used (and in the Japanese version none are), but the MPAA demanded measures be taken to tone the scene down.
Answer: No, I don't think it got anything to do with "gross level" - maybe the blood is not red, but body parts still fly around.
My own common sense tells me the goal of this technique is to put more focus on those scenes, draw the viewer attention.
This way those scenes are also much more "artistic" and give the movie whole new layer.. many times those things make the difference between "just another movie" and a cult movie.
Couldn't find any official explanation, so I stick with the above two reasons.
Answer: in Japan it is in color but no English subtitles for the extensive Japanese, in the film.  It is way better in color.  If i guess at why B&W here in the states it is because of  the gore factor it is not typical Hollywood but realistic or not it is much more hardcore and the B&W tone it down about 1000%  if you are a fan of the movie you owe it to yourself to see the Japanese version
Answer: I think it concern with the goriness of the scene... If we see the fight the color comes back when Uma Thurman blinks her eye and immediately owner of that place shuts the main power and the color changes to dark blue to minimize the red color of blood.


How to prevents my kittens from putting nose in my coffee

Question: I tend to enjoy what are effectivly a solutions of various poisons in water (AKA tea, coffee and coffee with milk). They are not exactly healthy for my babies so I need to have constant vigilance. Is there an easy hack so I can enjoy both the presence of my kittens and a cup of coffee?
Answer: You can drink your beverage out of a to-go cup designed to be covered (usually to prevent spilling hot drinks). They also make more-robust personal tumblers which serve the same purpose, but are designed to be washed and reused over and over. That should keep the family pet from sampling your morning brew.

Product Search: Hot Cup with Lid
Product Search: Coffee Tumbler
Answer: In addition to the purpose-built cups and mugs with lids and covers, here's a Lifehacks answer. (inspired by a Robert Cartaino comment)
…
Place a small, light-weight saucer or "coaster" on the cup when you put it on the table or counter between sips. There's probably a perfect one sitting on the shelf in your kitchen or pantry.
This has the added benefit of keeping your drinks hotter or cooler than when left uncovered.
Answer: Might look very odd, but how about stretching part of a pair of [clean] tights (US, pantie-hose) over the top of the cup, secured by elastic bands.
You can drink through it, but the best the cats are going to get is a lick of the damp hosiery.
Alternatively, if somewhat cynically... why not put it where they can't reach :/
...because a dollar to a bag of buttons, they'll knock it over eventually...


When rolling with disadvantage what is the chance to get a 1?

Question: When you roll with disadvantage is the chance to get a 1 5+5 for 10% or 5X5 for 25%? Just sat down and rolled 100 times with disadvantage got 18 natural 1s and 0 natural 20s. Still don't know.
Comment: "rolled 100 times with disadvantage got 18 natural 1s and 0 natural 20s"  Do you mean you got no 20's on either die at all, or that no result of rolling with disadvantage came up double 20's?
Comment: @LegendaryDude The second one sounds more probable, since the chance for a nat 20 with disadvantage is 1 in 400 (which this simulation hasn't gotten close to). Not rolling a single 20 in 200 dice rolls is 1 in 28,000. Though, that is almost twice the expected number of nat 1's. Quite unlucky.
Comment: @markovchain That's exactly what I was thinking, and I was wondering if that difference is what lead to the question being asked.
Answer: The odds of a natural 1 are 9.75% and the odds of a natural 20 are 0.25%.
When you roll 2d20 you have 400 possible combinations of numbers. For a natural 20 there is exactly 1 possible way to get a 20 when rolling with disadvantage (20 on both dice) so the probability of getting that value is 1/400 (or .0025 or .25%)
For a natural 1 there are 3 different possibilities that can result in a 1 when rolling with disadvantage, 1-1, 1-X, and X-1 (where X is not 1). There is 1 way to get 1-1, 19 ways to get 1-X and 19 ways to get X-1. Adding all of those up we get 39 different ways to get 1, so the probability is 39/400 (or .0975 or 9.75%).
As a note your 5% + 5% comes close, but you are double counting the 1-1 combination.
Answer: There is a \$9.75\%\$ chance that you will roll a 1 with disadvantage.
Math
The chance to roll a 1 on a fair d20 is \$1\div20\$, or \$5\%\$. From this we can use statistics to determine what the real odds are.
We care about a couple of scenarios here:

Odds we roll a 1 on the first die and the second die.
Odds we roll a 1 on the first die and not the second die.
Odds we roll a 1 on the second die and not the first die.

The above scenarios are all the ways we can end up with a 1 when rolling with disadvantage. The fourth scenario will be all the other results.

Odds we roll no 1s.

For the first scenario we have a \$5\%\$ chance, twice. That means we can multiple the percentages:
\$5\% \times 5\% = .05 \times .05 = .0025 = .25\% \$
Fun note, this is the same as the odds of rolling a natural 20 with disadvantage!
Now, let's check the next two. For scenarios 2 and 3, the math will actually be the same. We'll take the odds of rolling a 1, and multiply them by the odds of rolling not-1. The odds of not doing something are simply 100% minus the odds of doing that thing. That means the odds of rolling a 1 are still 5%, and the odds of rolling not-1 are \$100\% - 5\% = 95\%\$.
Scenario 2:
\$5\% \times 95\% = .05 \times .95 = .0475 = 4.75\%\$
Scenario 3:
\$95\% \times 5\% = .05 \times .95 = .0475 = 4.75\%\$
Finally, let's check the odds that we don't actually roll a 1 at all! This will be the odds of rolling not-1 twice in a row!
Scenario 4:
\$95\% \times 95\% = .95 \times .95 = .9025 = 90.25\%\$
Now with a little bit of math we can get to our final answer!
To get the odds than any of the first three scenarios will occur, we can add them together:
\$.0025 + .0475 + .0475 = .0975 = 9.75\%\$
This means that, according to our math, there is a 9.75% chance that you will roll a 1 with disadvantage. We can check that number, though, to be sure our math is correct. That's where our fourth scenario comes in! In statistics, the sum of all possible scenarios must add up to 100%, otherwise you're missing a scenario. To be sure we didn't leave anything out, let's add up our numbers:
\$.0975 + .9025 = 1 = 100\%\$
So you can see that, unless we made some larger errors in our theory, we did in fact cover all of the possible scenarios. You might also notice that there's a short-cut to getting out answer here. If we simple take 100% and subtract the odds that we roll no 1s, we can get the final answer much quicker!
\$1 - .9025 = .0975\$
These kinds of statistical shortcuts are pretty cool, and can save a lot of time!
On Physical Dice
As you note in your question, your dice don't seem to match with reality here (you fumbled twice as often as we would expect!) there are a few explanation for this.

Not all dice are fair. Many dice are produced on the cheap in factories with minimal quality control. Most of the time these dice aren't too far off of fair, but sometimes they can be heavily weighted, affecting outcomes.
100 die rolls simply isn't a very large sample size. It's a good start, but if you look in the Math section of my answer, you'll notice that the odds of rolling a natural 20 with disadvantage is only .25%, that's a 1 in 400 chance that means that it would take 400 rolls to expect to see a single natural 20 with disadvantage! Even at 400 rolls you're not guaranteed to see one! Most statistical simulations are done with thousands or millions of samples for this reason. The more samples you have, the better you can trust your measurements!
Comment: Thanks! As for why I fumbled twice as often, that's me. I was trying to prove to my DM by rolling in front of him how disadvatage was huge in terms of probabilities so trying to roll a 1. I did roll a 20 on one of the dice several times. One of my dice was one I call the dice of chaos which seems weighted to come up with either 1 or 20 about twice as often as normal. Which is fine by me, either way something interesting happens.
Answer: Neither, it's 9.75%.  The odds of rolling at least one 1 are the odds of not rolling a 1 twice, or 1 - (.95^2).
Comment: Your answer is correct but would be greatly improved if you explained how you came to your conclusion.  "The odds of rolling at least one 1 are the odds of not rolling a 1 twice" is not intuitive to someone who isn't familiar with how probabilities work.
Comment: For completeness sake, the chance of rolling a nat 20 is 1 in 400.
Answer: It's \$9.75\%\$. To calculate this, you need to do some double-negation. First, you calculate the odds of not rolling a 1. The probability of rolling a 1 is \$5\%\$, so the probability of not rolling a 1 is \$\left( 1 - 5\% \right) = 95\%\$. With disadvantage, though, you roll twice. The odds of doing something twice in a row is the individual probability squared, so in this case \$\left(95\%\right)^2 = 90.25\%\$ is the probability of not rolling a 1 on both dice. Then to get the odds of rolling a 1 on at least one of them, we negate this again: \$1 - 90.25\% = 9.75\%\$.
Answer: Neither, it's 9.75%
The odds of rolling a 1 are, as you correctly identified, 5% or 0.05.
The odds of an event (rolled "1") occuring at least once are complementary (100% - ... or 1-...) to the odds of the event not occuring at all (which means that for a given number of independent attempts X, each attempt will result in "not 1").
P("1" >= 1) = 1 - P("1" = 0) = 1 - P("not 1" = X)

The probability of an event occuring X times in a row is the individual probability to the power of the number of consecutive occurences:
P("not 1" = X) = p("not 1")*p("not 1")...p("not 1") = p("not 1")^X

The odds for rolling anything but a 1 are 95% or 0.95. Which brings us to the final result for X = 2 attempts:
P("1" >= 1) = 1 - P("1" = 0) = 1 - P("not 1" = 2) =
            = 1 - p("not 1")^2 = 1 - 0.95^2 = 0.0975 = 9.75%

See also this question in math.SE.


If devas are real, than why don't they show us themself?

Question: If semigods/devas/dities are their, than why don't they tell us that they do exists, so that people will follow dharma with out doubt?
Comment: @user3293056 According to [MN 26](http://www.accesstoinsight.org/tipitaka/mn/mn.026.than.html) and [Wikipedia](https://en.wikipedia.org/wiki/Brahm%C4%81_(Buddhism)#Brahm.C4.81_Sahampati), `Brahmā Sahāmpati, said to be the most senior of the Mahābrahmās, was the deity who visited the Buddha when he attained enlightenment, and encouraged him to teach the Dharma to humans.`
Comment: not to play the fool, but do devas have the dharma, or do humans?
Answer: They are around, just that you don't see them. Likewise bacterias are everywhere, you don't see them.
Not seeing/hearing is not existing obviously is scientifically proven false, but people tend to dwell in this fallacy without remorse.
The way to learn is to improve the capacity. Bacterias can be seen by inventing microscope, but the Buddha seen them 2500 years ago. Maybe one day someone can invent devascope to see them; yet again you can learn what Buddha was capable and see them ?year ahead the inventor ~ :D

- The OP asks for elaboration, I extend my answer -
Dialogue for those who's minds are not contaminated by the neo-Buddhist. (Neo-Buddhists - those who believed in their "scientifically-authenticated-Buddha".)
Prelude:
Buddhists from tradition and Buddhists at heart are seeing the emerging of the trend of neo-Buddhism, a Buddhism invented by applying so-called scientific methods, surgical skills and dissecting analysis are callously utilized. Taking the convenient standpoint that Buddhism is a religion/(not a religion) appealed to reasoning, unlike Christianity or other faith-based. Therefore, anything that's not scientifically proven should be stripped, for it's either misunderstanding/mis-translating the words, primitive superstitions or later additions by fanatic religious... etc. In a nutshell, they want to reduce the Buddha to be a merely human, any feature of Buddha a Buddha is committing suicidal scientific fraud.
Traditional Buddhist and Buddhist at heart knows the Buddha is the Buddha, yet Buddha is also human therefore it completed the teaching that we humans can become the Buddha, or be liberated forever like the Arhat/Arahant by dwelling in Nirvana.
The blindness of the neo-Buddhist is that they equal reasoning with science. Science is only one of the many methods for searching the ultimate, science is not the ultimate. Reasoning includes scientific methods, but scientific methods not the totality of reasoning. Buddha's teaching is the teaching from the ultimate, he is not searching for the ultimate; reasoning is a method taught by the Buddha to realize the ultimate by oneself, reasoning itself is not the ultimate.
We are seeing science characterized by the ability to re-adjust itself, such as Newtonian physics disproved by Einstein's Relativity. The day will come when E=mc2 being disproved (I said the c, speed of light, is false. How do I know? I learnt it from the Sutras - not directly the Sutra with explicitly this saying but one has to really get it). This is the goodie of science - being able to adjust; the very way science survived is by disproving itself. Applicable is this rebuttal logic used by the Epicurean refuter on "pursuing happiness is the very reason happiness will never be obtained by the pursuer", likewise science is refuted. We can never predict what science will come up next, but surely can predict whatever come up next will be refuted late; hence a sound mind can infer thus see clearly that "scientific methods" we called nowadays can never obtain the ultimate. Therefore, can we trust scientific authentication? You know better than me. Do you trust someone who come up day after another day, time after another time, telling you, "Sorry, what I said before was wrong, in fact it should be so and so...?"
The Dialogue:
Why don't the Devas show us themselves? I don't think I can answer this question on behalf of the Devas, or as the envoy of the Devas ;). Ultimately one should get his own answer by knowing it directly himself. But I put in my two cents to enrich this investigation:
A) It's really as hinted above, they are around but we don't see them since we don't have the ability to see them, nor it's their duty to let themselves be seen by us.
Here is the incident I read in the Vinaya, that may illustrate this: A Bhiksu/Bhikkhu chopped down certain village sacred tree for building his little hut, the tree Deva's kid just playing around that tree accidentally being chopped off his finger. The tree Deva, devastated, went straight to complain to the Buddha... You see, here this Bhiksu is definitely unable to see, if, for example, he didn't get accomplishment in Dhyana/Jhana. Else he wouldn't chop off the Deva kid's finger, nor it's for the kid to make himself visible in normal circumstance; the Deva didn't file complaint to him directly since he wasn't able to see him.
B) Only with special cause that the Deva to the human can be seen.
A case to illustrate this is from a linked Sutta I read in this forum. In it talked about a Bhikkhu visited by a Deva requested to bring him to the Buddha for asking a question, for the Buddha was surrounded by many higher Devas he didn't have a chance to get near. The reason for this Deva to seek for his help was due to in eons lives before, they were relatives... or something like that.
Therefore, there must be cause (Karma) to fulfill the criteria. Likewise, Aishwarya Rai won't come to see everyone in Mumbai, but she may come to see her friend if she has one there.
C) It's not allowed for the Devas to take "mass-appearing" to induce people following Dharma/Dhamma, for it violated the rule:
(i) Another incident I read in Vinaya, about Maudgalyāyana/Moggallāna being accused faking Dhyana/Jhana for he told the rest that State A would win the battle against State B for he saw the Yaksas (city protecting Deva of State A) winning the other Yaksas in their battle. But it turned out the opposite for while M. reporting this the battle of the Devas made a significant turn...
(ii) Another case I read from the Sutra, said Śakra/Sakka paying tribute to the Buddha for Buddha's teaching turned more people to good hence it increased his citizens decreased the Asura's citizens.
Therefore it shows that the Deva worlds and human world are synchronizing, the battle of the Devas is playing out in the human world, so is the human world reflected back to the higher realm. Imagine, if the Devas made their mass-appearing to induce followers, then the Asuras will do the same, then the battlefield will be shifted to the human world... can the human world sustain such turmoil? (I think the Mahābhārata was such event happened eons ago when Planet Earth was the celestial realm, or semi-celestial realm, before it degraded to be only suitable for humans).
(iii) Last, the Parinirmita-vaśavartin (pleasure from other's pleasure), the highest of the celestial realm ruled by desire, the Lord of this realm is Mara, named Pāpman (Pali: Pāpiya or Pāpimant), his sustaining and joy is produced by the desirous activities carried out in the lower realms, particularly the human realm, he won't allow this mass-appearing, he would prefer humans staying in Samsara, being under his rule.
Ok, it's a bit too sophisticated for it related to ample studies in the Sutras, Vinayas and Sastras to understand, especially many of the sources are not available in English.
The above is very pictorial, vivid, narratively dramatic... for in the tangible it manifested as people, places, events... but in the intangible, it should be decipher differently.
... is it enough now to buy a Big Mac meal in McDonald's, huh?
Comment: they maybe around, and maybe humans can't see them. but my question was why they/ devas don't communicate with us? are devas unaware or unconcious who don't know of their own existance? why don't they communicate with humans? are just just energies of universe or something which is self aware?
Answer: You need to develop the divine eye faculty to see Devas and ghosts. Read the  Visuddhimagga if you are genuinely interested in it.
Answer: When you walk in a park and find some ants walking in a row, bend down and look at the ants and observe what they are doing. Then wave your hands at them and say, "ants, how are you today?". They don't respond back. If you place your finger somewhere near their path, they would ignore it and continue onwards.
You would find that the ants are completely oblivious of your presence.
Similarly, the devas or brahmas who are said to be superior to humans, may be watching us and attempting to interact with us, but we may be completely oblivious of them.
We don't need to trust that the teachings of the Buddha are true by proving that devas and brahmas exist. All we need to be convinced of, is that the Buddha was truly enlightened in the nature of reality, just as we trust what Einstein taught in physics, because we are convinced that Einstein was enlightened in his area of physics. And just like physics, the Buddhist teachings are very empirical, in the sense that it is verifiable by practical experience.
In this answer, I stated that it's quite possible  to have "retrograde realization" (to quote Andrei Volkov) i.e. to realize upon reading some teachings of the Buddha, that it really fits your own observation of the workings of your mind. However, if the Buddha did not point it out, you would not have noticed. This kind of "aha" moments can convince you also, of the truth of the Buddha's enlightenment and skill in teaching.
You can read the story of the world's happiest man, Tibetan Buddhist monk Matthieu Ricard, through whom neuroscientists empirically verified the efficacy of the Buddha's teachings, using 256 sensor nodes. Ricard also encouraged us to similarly verify the Buddha's teachings in his statement: "Try sincerely to check, to investigate. That's what Buddhism has been trying to unravel — the mechanism of happiness and suffering. It is a science of the mind."

To quantify just how happy Ricard is, neuroscientists at the
  University of Wisconsin attached 256 sensors to the monk's skull. When
  he meditated on compassion, the researchers were shocked to see that
  Ricard's brian produces a level of gamma waves off the charts. He also
  demonstrated excessive activity in his brain's left prefrontal cortex
  compared to its right counterpart, meaning he has an abnormally large
  capacity for happiness and a reduced propensity towards negativity,
  the researchers say.
During the same study, the neuroscientists also peeked into the minds
  of other monks. They found that long-term practitioners—those who have
  engaged in more than 50,000 rounds of meditation—showed significant
  changes in their brain function, although that those with only three
  weeks of 20-minute meditation per day also demonstrated some change.
Answer: First, we have to distinguish between mundane devas and supramandane deities. The mundane devas can either follow Dharma or not, but usually they do not,  because of their illusion of everlasting happiness. This means they are not compassionate and so they don't have a cause to deign to humans, nor human beings have an ability to see them, just like ants don't have ability to see humans and/or communicate with them, or just like humans usually don't treat ants as their peers.
Second, those mundane devas who follow Dharma might be compassionate, yet they can hardly be noticed by those humans who haven't achieve an ability to see devas and/or supramandane deities.
Last but not least, the supramandane deities require a practitioner to have special abilities and/or to be determined by some special causes to see them. E. g. all the  - if I am not mistaken - Kashmiri women put together are the manifestation of the Shri Devi's speech, yet which mortal can perceive all the Kashmiri women at once?
Answer: Good people have no doubt in Devas, having no doubt in devas, they watch out their deeds, knowing that they are next and here. Watching out their deeds, they are no more ugly and bad smelling for Devas and those established in good ways are not deprived to come even in a human life in reunion with them.
Devas, like good people, avoid uglines and bad smell. Those who watch over their qualities are not in lack of their company.
Would you, for example, join a community of pigs and act in their ways so that you get recognised and be followed by them? What else as a pig keeper, those who gain benefit of them, would a common pig follow aside of it's kind?
Likewise Devas do not appear to common men, will be not found in their reunion. Even if they appear from time to time, it's not for those incapable to see and hear the meaning of their voice.
Maybe an inspiring story for those open to it:

"Devas possess divine sight and divine hearing, enabling them to see and hear over great distances. They know about the good and bad of human affairs better than do humans themselves. Couldn't you find a way to make humans more aware of right and wrong? I feel that you are more capable of it than we human teachers are. Is there any way you could do this?" ...An Impeccable Human Being

[Note: This is a gift of Dhamma and not meant for use of commercial purposes and other wordily gains but intended and bound to awakening and liberation, and so good shared.]
Comment: Upvote for mentioning *"Devas... avoid uglines and bad smell"*. It's very true, mentioned in many places in the Sutras.
Answer: They are as real as Adam and Eve ie a metaphor. From what I gather through various readings and podcasts the Buddhist story of Mara is also not meant to be taken literally. These are fables.  If a demon did appear it would have been in Siddartha's mind.
Its unwise to take religious teachings literally in my opinion. You only have to look to these Christians who do so with the Old Testament to see the negative effects it has.
Answer: There is no reason to assume that the gods follow dharma. Some may. Others may not. It is my understanding that it is best to be human since humans have the combination of opportunity to practice and the suffering that that can motivate to practice. Gods with less suffering are not as motivated. But back to the original question, people make their own choices with or without gods, miracles, evidence, and so forth. This is what I love about buddhism. It is based on logic and evidence. You do not have to take anything on blind faith. Experimentation with positive practices produces positive results. Succumbing to negative states (anger, grasping, etc.) produces negative results.


Skipping AMEB Music of Theory grades?

Question: I understand that each grade teaches musical terminology, etc.that will be incorporated into the next grade, but I was wondering if skipping AMEB Music of Theory grades was possible or is there a required grade that I have to take? Or is there a limit to how many grades I can skip? If no, what grades do you recommend I can skip (provided that I just briefly study the needed knowledge but not take the exam)? Cheers ~
Answer: Grades are often skipped, both practical and theory.
In ABRSM, not sure about AMEB, grade V theory must be passed to be able to enter grade VI and above practical.
The theory syllabus is usually cumulative - it keeps adding to the previous stuff - so just looking at, say, grade V, will not give you enough information to pass. You'll need to be aware of all the things in the previous syllabi. So yes, skip the exams, but not the study.

Skipping AMEB Music of Theory grades?