I recently read a blog post on literate programming and that tex was written using this paradigm. So I thought it might be a good idea to read the original tex program's source, by Knuth himself (the pascal version) in the literal programming style. However, having downloaded the distribution, I only find the raw file tex.web in the directory, and the tooling available via package managers (ctangle, cweb) only works with C files. So I was wondering whether a PDF file with the literate programming output was available on line, yet an hour of searching online did not yield a result. So: Is there the literate programming output for humans available for the tex processor?


I was solving a practice Physics GRE and there was a question about springs connected in series and parallel. I was too lazy to derive the way the spring constants add in each case. But I knew how capacitances and resistances add when they are connected in series/parallel. So I reasoned that spring constants should behave as capcitances because both springs and capacitors store energy. This line reasoning did give me the correct answer for how spring constants add, but I was just curious if this analogy makes sense, and if it does, how far one can take it. That is, knowing just that two things store energy, what all can you say will be similar for the two things.


Let A be a an infinite set. Let B be a subset of N, where N is the natural number Say there is a one to one correspondent between A and B. However, B is not the whole natural number. B is only a subset of a natural number. Intuitively, this is very clear. N is even "bigger" than A. However, how to go from that to actually finding out that there is a one to one correspondence between A and N? Basically I am checking several different definition of countably infinite. One requires a one to one bijection between A and N. The other requires only an injection from A to N. The latter seems to be a weaker requirement.


I took a course in vector analysis this year. It was a two fold course. The first part covered linear algebra and basic euclidean geometry. The second took to more advanced areas such as differential geometry, and the integration theorems. We used vector analysis by Schaum(author: Murray Speigel). I was wondering if there are more books on the subject? Please make sure you state the things covered in the textbooks you mention.


When Studying the phenomenon of precession a classic example installation is this: a wheel spins around the Y axis, gravity applies and the upper part starts spinning around the Z axis. The textbook explained this with angular momentum, looks simple, but it is really weird when I try to think about this in other ways. Usually when i see something start spinning, i think there is an force pushing it, but in this case I can't find such a force. There is a kind of gap in my head, and it really disturbs me. Please help me.


Suppose there is a slanted capillary tube and a fluid rises in it. Why does the fluid rise to the same vertical height as when the tube is perfectly vertical? If I'm right surface tension force balances the weight of the lifted fluid. But in the case of a slanted tube, more fluid will be lifted and thus weight also increases. So why will fluid rise to same height?


Raring definition: very enthusiastic and eager to do something. I want to use rares, as in: He rares himself up, ready to tell her. I'm wanting to use it as in the cited example, meaning he gears himself up, sort of like an instant pep-talk, like readying himself. But it looks as though rares isn't a word for what I need it for. Can I use it like this or not?


I am thinking about possibility to parse LaTeX document. What I really need is to track category codes of symbols. As I understand TeX expands all of macros in his mouth and tracks changes of category codes without executing anything. Is it possible to check if the next token is a macro, collect it unexpanded (together with arguments), execute it and move to next token?


Could anyone clarify to me the following: Lightning gives off high current when it hits a car/vehicle, and since the electrical components of the car is grounded on the chassis, are there possibilities that these high currents can destroy or damage the electrical components,battery, antenna etc through the 'grounding'? what are the 'areas' or 'lightning zones' on my car which have the possibility of getting struck by lightning? My friend says the car is being 'positive' with respect to the ground(Earth) hence the lightning which is mostly negative flash tends to strike the car, How can the car be positive when the entire exterior of the car is mounted on the chassis which is negative?


If we have n gaussians where they have different scale and location parameters -- are they orthogonal to each other? By orthogonal I mean that the inner product is zero -- like it is for two cosine functions that have a different phase. So, by Gaussian I mean the normal function used for it's properties as a function and not as a source of Random variables.


This can also be applied to client-server interactions (which is what I need it for). For example, if you (the client) send data to the server or retrieve data from the server, what is the name of the server in that instance? Or, if the server sends data to the client or the server receives data from the client, what is the name of the client in that instance? Both of these names should be equivalent. Basically, I'm looking for a word (or words) for the other person/entity when the two are connected.


I use Kile on Linux and WinEdt on Windows both with same version of MiKTeX. While using KILE, when I compile "PDFLaTeX" , it updates my opend output pdf file and does not close the file. Where as in WinEdt it closes the already opened output pdf file and open it again after compiling. What irriatates me is while it opens the new output and it goes to first page rather than the page (of output pdf file) I edited. :( Any remedy would be appreciated.


There is a company out there that 'prints' magnetic pixels, a.k.a. maxels, into a material. In doing so, they're able to choose the distance of effect of magnetic fields they create, independently of the magnitude of the field, leading to some really interesting properties. Can anyone shed some light upon how theyre able to 'print' a 'maxel' into a material? Here is a good video by Smarter Every Day about this company and their process.


After reading "Is everyone" singular or plural?", I would refrain from asking this question, but the husband of a colleague of mine (English professor, native speaker of British English) stated against it, so I am looking for further enlightenment. He advocates some should be solely used to refer to plural forms. Thus, some non-existent towns is perfectly correct, but some non-existent town should be replaced by a non-existent town Is that true?


Many basic types of physics have ready and obvious everyday applications. For instance, basic electromagnetism vector calculus can give great insights into how something as simple as a bar magnate works. And obviously the more people understand the science the easier it is to apply it. My Question: What are some examples of useful or practical applications of classical electrodynamics and quantum electrodynamics? I'm hoping that by getting some examples it will help me better understand why physicist seek these elaborate tools to describe physical phenomena.


I find it difficult to understand the sentence as shown in the title. Is the card data? Is the card processing? Is the card a method (or style) to process data? I'm Chinese. If I express the sentence with Chinese I'll say The punch card was the main method of data processing back then. NOTE: I'm a programmer and I know what a punch card is. So please don't waste you precious time to explain the punch card.


I understand how to get the vertical (descent speed) of a parachute and its payload, but how could one find the horizontal speed/velocity of this parachute depending on the speed of the wind? (yeah I understand the higher the wind is, the smaller it's influence is as well) I'm having a hard time trying to figure out what the winds influence on a descending balloon is. I know it would push the parachute, but how much would that matter? I know it would push the payload, which trying to figure out a CD for would be rather hard!


I am looking to test some properties of elliptic curves and I would like to have a variety of different families to test. I was wondering if there was, say, a catalogue of the different interesting families of elliptic curves that have been found. Some types of families I am interested in would be: families of high rank, families of a given rank, one-parameter families, or families of even rank. Thank you in advanced.


English is my second language. I heard someone saying "Now that the right people are telling the vote..." I wrote down 'telling' but I don't think it was that word. What could that verb be that could sound like 'telling' to mean "...now that the right people are voting..."? I'm pretty sure it wasn't "casting". Situation is like in the 'survival' show. There are two teams and the loser team was to pick someone to leave. That line is said before they are going into the area to pick each one's 'worst performer' choice.


As the resistance of a circuit goes down, the power increases because the current increases, assuming constant voltage. Why is this? I feel like resistance and current are inversely proportional, so lowering one should just raise the other, and power should stay relatively constant. What is it about power that makes it work like this? Edit: Again, namely I find it confusing that decreasing resistance actually has a net increase in power used. I feel like while the current will increase, it should be countered by the lowered resistance...


This is related to this question:Does the weight of an hourglass change when sands are falling inside? At Brigham Young University, there is a display consisting of a sealed off liter bottle with a sunken sealed off hourglass. When one turns over the bottle, the hourglass floats as the sands flow down. Eventually, the hourglass reaches some transition, and precipitately changes from floating to sinking. It has a sign next to it saying that it's for a fishing lure,and that you should not reveal the answer if you get it. What causes it to change from floating to sinking so quickly?


How do I represent the -ed in witnessed (or any other similar word) phonetically? Is there a reference sheet somewhere for these? I notice that other endings do not get shown in most dictionaries either (for example -es in phrases) I use Word web which has a pronunciation guide for the root of the word, but I can't find anything to write the -ed part phonetically. It does not seem to be on this Wikipedia page. I would prefer the same format as Word web. Many people could probably figure this out for themselves (without a direct reference), but I do not trust myself.


Considering a Science Fiction question, it occured to me that in "populated" space, with no atmosphere, you might expect to find more EM interference than on Earth. Basically, if you are outside of an atmosphere, are there issues with using radio as a mass communication method, based on the difficulties with spectrum management when the atmosphere isn't degrading signals? And would there actually be more interference from the radio emissions of celestial bodies once you leave Earth's atmosphere?


I encountered the following two examples: Moreover, the proposed scheme is designed in an ID-based setting and so the necessity for certificates and some related problems are eliminated. Our scheme also achieves setup-freeness and so a user can enjoy the fairness provided by the fair exchange scheme without interacting with the arbitrator for registration. Is this type of construction (and so) correct? Should there be some commas somewhere? Are they not just two independent clauses joined by and so?


What do you call someone who, merely by their presence, gives a morale boost to the people he is responsible for? What about someone who gains power from being supported by their troop? If possible I would like to have word with military connotation, but a more "civilian" approach is also interesting. EDIT: Jez gave a lot of interesting examples, but I am also interested in nouns, and all of Jez's example can't be "translated" into nouns that easily.


I have some doubts about the usages of that and who. Sometimes I read sentences such as You are someone I love. You are someone who I love. People were asked to describe the qualities they look for in a friend. People were asked to describe the qualities that they look for in a friend. Why are who or that omitted in some of these sentences but not in others?


This question is related to Compiling documents online. I store my LaTeX documents in a git repository on GitHub. Is there a web service which offers a post-commit hook for GitHub which automatically fetches my document and compiles it? For example, ReadTheDocs provides compilation for documentation of Python projects stored in GitHub repositories; the documentation is fetched and compiled after each commit to the repository.


I cannot think of any single word that means a person's life changed for the worse. While there are many phrases, i.e. fallen heroes for good guy turned bad, or take a turn for the worse, turning to the dark side,I cannot think of a single word that describes this phenomenon. An example would be in my subjective opinion, how Lindsey Lohan a child star took drugs as she grew older or Harvey becoming Two-face in Batman. The sentence structure should be: He/She __________. And they would get the idea that their life turned bad or took a change for the worse.


I've started studied eigenvalues and eigenvectors. If there is a transformation T: V->V I can find out a matrix of T with fixed basis and characteristic polynomial of T. With this characteristic polynomial of T, I can find out eigenvalues and eigenvectors Does this mean that this transformation T: V->V has eigenvalues and eigenvectors? And, If there is a transformation T: S->V, S is a subspace of V. then Matrix of T is not square, and therefore I can not find out characteristic polynomial. Does this imply that there exists no eigenvalues and eigenvectors under Transformation from subspace into Space ?


While working on a menial task in front of a clock today I was distracting myself by proving that all three hands only align twice a day. That lead me to wonder how one would deal with more complex problems involving modulo arithmetic. I know several rules for reducing equations involving all sorts of operators from simple addition up through very complex triple integrals and the like. But, I never learned any rules for manipulating the modulo operator. What are valid operations that can be used to reduce equataions involving multiple modulo operators?


Having taken none of the prerequisite rigorous treatments of mathematics during my undergrad years, I feel at a disadvantage to the people in my major what do have that analysis/abstract math background, I always find myself struggling to understand those more rigorous papers that use concepts from real/complex analysis, topology, set theory and the slew of abstract math concepts that you don't typically see in engineering at an undergrad level. What sources are especially good for starting to understand more rigorous math and why are they good? I specifically deal with controls, stability of dynamical systems and probability, so any books that are especially good for those fields are even better.


I remember at more than one university math department there being a set of glass cabinets with a number of physical models of surfaces. They were all algebraic varieties on the reals (of limited degree). I am looking for a reference (online or physical book) for a systematic listing that would show images of these surfaces. I looked at the Mathematica site but it seemed to only have polynomial functions. Is there an online or library reference for these?


I think of mathematical objects as individual things that exist by their own (either abstractly or concretely) and can be represented mathematically. When thinking of subsets, I'm in doubt if they are really mathematical objects because they must be related to something (a set) to exist and be called subsets. If they are not related to anything, they are just sets, mathematical objects for sure. So, are subsets really mathematical objects?


I am learning about the degree of algebraic sets. I know the definition from Wikipedia, but it is not too clear to me what it is. Could someone possibly explain to me exactly what property the degree of an algebraic set does capture, or how I should think about it? PS: This was part of another question of mine, Basic question regarding degrees of algebraic sets, but I thought that maybe it would be better to ask this separately.


You are walking around a circle with an equal number of zeroes and ones on its boundary. Show with induction that there will always be a point you can choose so that if you walk from that point in a clockwise direction, you will always have seen at least as many zeroes as you have ones. So, suppose the P(k) case holds. In the next case, where an extra one and an extra zero is added, I can see that the old path will suffice so long as you will encounter the extra zero before the extra one. But what about in the other situation, if you encounter the extra one before the extra zero?


The four words"weakness", "shortcoming", "demerit" and "defect" are four words shared with the similar meanings. In the dictionary, "weakness" and "shortcoming" have more to do with one's characer, while "demerit" and "defect" are used in a general sense. However, in this sentence, "The ___in David's character has hindered him from advancing in his character." Why the correct answer was said to be "defect" rather than the other three?


Does the word nationalism specifically imply a feeling of kindred superiority in a secular sense? For instance, if country X opposes themselves to country Y based on religious practice or reasons, would we still refer to country X's behavior as nationalism? In this scenario let us assume country X has no issue with a third country where the same religion is practiced as in country Y. What if country X's claim to their homeland is based on a religious belief, would any behaviors which would have been classified as nationalism now be called something else?


My question is about the interact mode in Asymptote. On a OS X terminal, I type asy -v <name-of-file>.asy and go to the interact mode. A window containing the relevant picture shows up. After playing around, I have worked out an appropriate camera position and I would like to use the camera position that the picture is currently set in. Is this possible? In other words, how do I recover some data about the camera position? /p/s/ Although this question is a priori TeX related, the end application I have in mind is inclusion into a document I am writing using LaTeX. :-)


I was searching for information about the original novel "House of Cards" and from following site, in the middile of the page, there's sentence which compliment Kevin Spicey as shown below(http://www.michaeldobbs.com/house-of-cards/): He's not only one of the most talented actors of our age but kind, too. I don't think the "Kind" here means Spacey's a nice guy, I guess it might imply that he's a good actor of "man kind" (our kind)? I couldn't find any sentence with similar structure as an example to support my guess, so please anyone can explan to me the real meaning of the word "kind" here, better with some example, thanks.


Commonly seen in physics(and statistics) are the concepts of moments of order zero(mass), one(center of mass), and two(moment of inertia). In statistics a third moment (referred to as skewness) also exists and is used. Actually, mathematically the moment can (of order n) be simplified to an operation in the form of: Once I look at this equation it begs the question: what if n is a ratio. What could be some physical applications of this fractional-order moment?


I will not in any case kick the ball. I will in any case not kick the ball. I in any case will not kick the ball. I will not kick in any case the ball. I think only the fourth one is wrong, and all of the others seem fine to me. Please tell me if there are any wrong ones (and why), because after looking at them for so long, I just lost my sense of English. Also, please tell me if some of them have to be used with commas like below: I, in any case, will not kick the ball.


I have a set A with three elements. I'd like to express another set B in terms of a limited number of elements (two in this example) from set A. In this case I realize that there would be a number of possible B sets, but I'm interested in expressing that B could be any of those sets. Alternatively, set C which is one of the possible B sets. Is this possible, or should I be looking for some other notation than set theory?


I understand the electrons in circuit travel down the path of least resistance, however are electrons attracted by the emission of virtual photons emitted by a source with relatively low electron concentration or positively charged? Thus, relating this to a battery in a circuit, does an anode (in electron-flow notation) emit an electrostatic potential force that attracts electrons, aside from the path of least resistance? I am a bit new to physics, so if my question seems silly or wrong, please explain why.


All these classical ideas are pointless and obsolete today, because in quantum mechanics, the particles are completely different objects, defined by quantum motion of fields, not by the location of classical points (at least not in a causal field picture). The notion of a point particle was replaced by the more subtle notion of a quantum point particle, which has a probability amplitude to be at various places. This quantum point particle can reproduce the quantum field if it is allowed to go backward and forward in time. Ron Maimon That was quoted by Ron Maimon. From this - Can I gather that in reality, particles travel backward and forward in time or, is this just a mathematical expression or model?


While searching for the meaning I got this: Workaround - a method for overcoming a problem or limitation in a program or system. Which means almost the same as "solution". So, can we use "workaround to this" instead of "solution to this" in a sentence? For example, This issue is getting more complicated. I want a workaround to this. Math is not real fun unless you have the workaround to these equations. Is it okay to use this combination in a sentence? Does it hold a different meaning? And what are the other precautions?


Assume that I am advertising that a payment will be asked only if we actually execute a given job right, and I say: "if we don't do it right, we have been working for free" "if we won't do it right, we have been working for free" "if we don't do it right, we would have been working for free" Can you tell me what is the most effective and correct way to express (advertise) the idea (especially the correct choice of verbs), and are the above sentences wrong ?


It is postulated by many cosmologists that at the Big Bang time the universe was in an unusual low entropy state. Does this claim specifically mean that the entropy of the initial universe was zero? Is zero-entropy state unique for given physical laws? Is it possible that entropy was growing always so that only difference in entropy has physical meaning rather than absolute value? Was there ever negative entropy state?


It is certainly possible to create a mapping between hierarchies and some of the fractals: http://davis.wpi.edu/~matt/courses/fractals/trees.html According to wikipedia it is possible to deviate from the original fractal formula: https://en.wikipedia.org/wiki/Finite_subdivision_rule , so my (not so) educated guess would be that it is possible to write subdivision rules to display any kind of hierarchical data. By some of the non-hierarchical graphs we are lucky, since we can use clustering to make them more or less hierarchical and we can probably use the same rule inside the clusters: https://en.wikipedia.org/wiki/Scale-free_network#Hierarchical_network_model So my question is: Is it possible in theory to use fractals or subdivision rules to display random network data (which I guess cannot be clustered efficiently)?


I saw a lot of usage of machinery, mechanism, to be used with similar meaning as techniques, ways, methods,.... For example, my math teacher said the machinery in the proof of some theorem is not heavy. Mechanism is also used to describe how something works. I have actually been confused if they can mostly be exchangeable. Also are there similar terms that can be used in this kind of scenario? PS: I have asked similar questions before here, but the post got closed. cerberus encouraged me to ask again.


How far apart do scientists estimate was/were the dying star(s) that supplied the elements that comprise our sun, planet, and us? With stars so far apart and expansion of space (as I understand it) carrying things further away still, it would seem to be a low probability occurrence for sufficient quantities of elements blown out from across many light years to accumulate to birth a star system. And another related question, it would seem that when a star went supernova and blew heavier elements in all directions, that would result in mass densities for future star nurseries far away from the dead parent that were much lower than what the parent had, so won't favorable conditions for star births monotonically decrease?


Possible Duplicate: Capitalising a sentence whose first word is explicitly lowercase Should I change the structure of a sentence/add filler words to make sure that the sentence always starts with a capital letter? In programming language documentation, it is common for keywords to appear in titles. Assuming that the keyword is strictly lowercase in the language, how should that keyword be capitalized if it is used as the first word in a title? For example: int int is used to specify an integer type. -- or -- Int int is used to specify an integer type.


I want to describe a recurring situation that happens in the modern day when people craft an email that is "perfect" in that person's mind, and they end up re-reading the sent message over and over. Maybe they are re-reading the email because they are satisfied that all the details are covered, or to appreciate the email's conciseness and focus, or even appreciate the tone and word choice. Relish is the closest I've found, but since I'm describing a person who enjoys the written word, I would hope there is a way to phrase it in a way that is more poetic to the situation. E.g. the word or phrase itself should have special meaning, intellectual or otherwise, to writers.


What is "the thing that, in its simplest form, has a receiver and a button, and we use to open the door when somebody rings the door bell" called in English? When I'm speaking English I almost always ask somebody to answer the door or I answer the door myself but today I was thinking, what is that "thing" exactly called, is it a "Door Answerer" or an Intercom? In my native language, it is called 'AiPhone' or 'EF-EF'.


Would it be proper to use a valediction ("complimentary close") in a newspaper or magazine message wholly devoted to congratulating the media's readers with the New Year or some other holiday? An example message from the staff of a made-up media: Dear readers! From the bottom of our hearts we... Yours sincerely, Russian Industrial News' editorial staff. Or are valedictions more fit for personal communication? P.S. In Russia, such congratulatory newspaper messages are ended with a no-frills bottom-positioned line like "Editorial staff of [name of media]." I became curious whether this would work in an English-language media, or should one add something to embellish the ending.


As you know, graphs can be factorized in their component subgraphs, factors such as eventually semilattices, and so on. I would like to know about the precise nature of the relation that might hold (if any) between such graph decomposition(s) and the (unique) factorization of an integer number in its prime constituents. Is there any known theorem regulating such an alleged relation? Thanks in advance (examples are welcome).


Is there a word that means accessible to all? Possibly starting with "omni"? Specifically, to describe information: information that could be accessed by anyone is [omni...] "Public" would be a reasonable description, but perhaps there are similar words. The problem is that "public" information is not necessarily accessible. Scientific journals are public, but are not necessarily free to access. Books are public, but not everyone can access a library, etc. I suppose it doesn't have to be a specific word. I wanted a convenient term for describing the kind of information that does not currently exist: information that in an ideal world everyone could get to (Edited in response to the many valid comments)


Is there any reference (book/review article etc.) where the physics of heavy ion collisions is overviewed? To be absolutely clear about things, I am looking for a introductory review which covers the physics aspects of the progression through the following stages stable nuclei fireball quark-gluon plasma formation (cooling) hadronization hadron interactions and decay final observable particles (leptons, photons etc.) with special emphasis on parameters like time for these stages, relevant temperatures, particle densities etc. Apparently all the literature I have scanned through talks about bits and parts, a comprehensive big picture is unclear to me largely.


I came across this phrase in school and I became quite confused with whether it should be seen as a personification or not. It may be a collocation but does that mean it can't be a personification? 'Gathering' to me usually entails the getting together of people/ animals (animate) so if it is placed next to something that is inanimate (Storm clouds), do we automatically classify it as a personification?


NASA published a computer generated black hole image. In the image you can clearly see the event horizon and the light of background stars graduating from "smeared" to normal. However, between the event horizon and the smeared stars there is an area which looks rather normal. Why is this? If the smear is due to gravitational force, it should start right from the event horizon across the image, and not after some seemingly random distance.


A very basic question of mine: Whenever I read a proof I am able to remember it only for a couple of months. But I really want to remember it for at least one year or so if not more. Is it the natural way or is it that once you read a proof of a theorem you are able to recollect it even after a few years I am feeling quite frustrated in this regard because for an interview in Mathematics the interview committee asks all the basic proofs involved in solving any given problem What should I do? I know that there are many Mathematicians here who are able to share some thoughts on this topic


I'm willing to teach some software for high school students next summer, I have chosen Mathematica. What other scientific software could I teach to high school students? (Matlab and Maple don't offer much if they know Mathematica). Does Microsoft Excel offer anything that will help with the teaching of mathematics? What about middle school students? what should they learn? is Logo suitable for them or for high school students?


Each of the following sets spans a subspace of the complex vector space of all functions from C to C. (Here the scalar field is C, not R.) In each case find a basis for the subspace and prove it is a basis; state the dimension. exp iz; cos z;sin z exp iz; cosh z;sinh z i posted a similar question before, but this is in the Complex field and not real. someone please explain how to prove this?


I was browsing through KHAN Academy videos when I met the one which Explained why SSA is not a Congruency postutate. But I had this Diagram in my Mind(Different from the video) Click Here to see diagram Sorry that I cannot embed the image, as I have insufficient reputation Here AC = PR, BC = QR, ANGLE A = ANGLE P Now I feel that this information is enough to prove the Triangles congruent but my Book has no mention of it. Please Explain


When a person sees the word LaTeX the first time, they are likely to think of a rubber material whose name is simply typed with a weird choice of uppercase letters. This strange name leads to much confusion (even ridiculing) and is thus not the best choice from a branding perspective. Is there a good historical reason why, of all letter combinations you could put in front of TeX, Lamport had to choose La? Because of his own name? In other words, why is it called LaTeX?


Suppose one constructs a dialogue in which a second participant is clearly there just to provide ballast while the first participant (the author) promotes a point of view. You could refer to the second as a stooge, a prop etc. But I'm looking for an adjective, and "the stoogy guy" doesn't sound all that learned. (-: A better noun than 'stooge' might lead to a good adjective, but all I really need is the adjective.


I just stumbled over the verb "to wake", which according to various sources has two valid forms for the past tense: "woke" and "waked". Some further research stated, that there seem to be two (Old / Middle) English verbs - one strong, one weak - today's "wake" stems from, hence the two forms for past tense: waken, meaning to cease to sleep and wakien, meaning to stay awake, keep watch Now, as there are two origins, I'm wondering: Are there (subtle?) differences in meaning when using "woke" or "waked" today?


I have a follow up question to this question: Should you use a comma/period after "Thanks"/"Regards" in email signatures? My question is: when should you add a comma when starting a letter/email with Hello John, It was fun to see ... I am pretty sure that a comma goes after the name, but lately I have seen several people (academics) write Hello, John, It was fun to see ... with a comma after the Hello. I am wondering when a comma there is appropriate. I see this question Where should the comma be placed in the salutation of a letter? but I am wondering about the situation where you have a comma after the name also.


Wiktionary reads: concinnity: The harmonious reinforcement of the various parts of a work of art. Call it corporate social responsibility at work if you wish, but we simply think that under Howard Shultz's inspired and inspiring leadership Starbucks is just a damned well-managed company that has achieved the concinnity that distinguishes companies operating under the nontraditional FoE business model. (Google Book's source) Since I don't have OED access, can anybody say from where this metaphorical usage of the noun 'concinnity' comes? And what is, precisely, its meaning in non-literary contexts? P.S. Considering the relevance of this word in an economics context, I tagged this question by 'economics' tag.


Looking at this page about Bibtex I see that the article entry should be used when the work has been published in a journal or in a magazine. Suppose that I have a small manual/guide, which probably has not been published, but which totally looks like an article (in the classic Latex meaning), then I can't use the article entry in Bibtex because the journal is a mandatory field. What kind of entry should one use in these cases?


Suppose a metal ring is suspended inside a vertical inductor (with an elastic string ) when the circuit is open. When the circuit is closed, does the metal ring tend to jump up or fall down? Why? I tried to check the magnetic polarities. Initially similar polarities seem to be induced on the near sides of the ring and the end of the inductor, like S-S and N-N, so there will be repulsion at both ends. In such a case what should the motion of the metal ring be?


In a text about properties of aerogel I read some interesting facts - clothes with aerogel proved to be impractical, being far too warm to wear. If you isolated a house with aerogel and lit a candle in one of the rooms, after a few days the house would become too hot to live in, just accumulating the candle heat. What properties (thermal mechanics?) of aerogel allow it to be this good a thermal isolator? Would a sealed box made of aerogel work just as well maintaining the temperature of enclosed (solid) items in void - with no air inside the box?


I am writing a text which I will review later again and want to comment out only a part of a line (in between), something like this: Once upon a time, there was %in some galaxy far away% a nice and cute rabbit... When I review it again, I could decide if it is better to include that part or not. Is it possible to do such a thing?


I've just learned a word forbear which means to abstain from something or refrain from something. It was fine until that point, but the moment I learned the meaning of forbearance, I was confused because it had tolerance as its synonym. When forbearance is used to mean tolerance, is it implied that enforcement is what is abstained from? Then, why did it happen? Why did it become to also mean tolerance, not just abstaining from something?


Is it possible to extract any particular ion ( either positive or negative ) from ionized gas ( or plasma ) without spending any kind of energy for doing so. I want to design a system for my weekend project where I can separate out positive and negative ions from an ionized gas container, thus leaving behind only one kind of a charge in the container.


Across the world summer is a season of the year and we all talk about 'the summer' - do you have plans for the summer ? etc. But In America it is often taken to refer to the period of college vacation when students take temporary employment etc. e.g. She did charity work over the summer. This would not imply necessarily the climatic summer season, so much as the college vacation. It is my belief that we do not use summer in this way in Britain, unless we say something like What are you doing over the summer break? Can anyone supply further insight into this different nuance which is placed on what is simply a season of the year?


Let K be the class of all finite groups. Show that it is not a variety (closed under H, S, and P) and therefore not an equational class. It sounds pretty reasonable that K is closed under H and S. I guess you can create some direct product leading to an infinite group then, but why is it so? Shouldn't every direct product of finite groups again be finite? Of course, I have an uncountable amount of finite groups, but still I have to end at some point for my product.. and it should therefore again be finite.


If you have a sealed container partially-filled with water and then flip it upside down, the water will fall to the base under gravity. Would it be possible to increase the internal gas pressure sufficiently to stop this from happening? As in, could you have a gas pressure exert enough force onto the water to keep it from moving? Obviously would need a very strong container etc.


First part: The question is both about the continuity of the water vortex(whirlpool) to vortex in air in time and in space. About continuity in time,does the vortex of the water slowly produce a vortex in the air because the vortex at the surface of the water(circle) causes frictional forces on the air molecules and thus makes them move in a circle(on the boundary of water-air) and because air is a continuous medium it also creates a vortex? Second part: When does a vortex stop?And why(detailed explanation if possible-my knowledge in fluid mechanics go as far as the navier-stokes equations)?


It's just a matter of angle-chasing to show the following: Extend the sides of a convex quadrilateral. Draw the in-circles of the triangles (open or not) defined by an original side and the extended adjacent sides. Their centres are concyclic. Having produced the first cyclic quadrilateral we can iterate the construction. Playing with Geometer's Sketchpad suggests that, if we begin with any even-sided cyclic polygon and perform the same construction, the in-circle centres will always define a cyclic polygon. Am I right? Can anyone prove/disprove the conjecture? By dissecting the polygons into quadrilaterals sharing a vertex we can show that alternate angle sums are equal, a condition sufficient in the case of the quadrilateral itself but I suspect not in the general case.


The usual question and answer seem to be of the form What do you want to be when you grow up? I want to be a singer when I grow up. Should it not be What do you want to be when you have grown up? I want to be a singer when I have grown up. Here we have interpreted grow up as the process at whose end one becomes a singer. Should the first pair be considered correct simply because of its accepted usage, or is there an alternative explanation for this?


I'm looking for a professional-context appropriate synonym for the word "a lot", but with the additional expression of "each contributes only a little" For example, To fill up that vat you'd need a crapload of tennis balls. Here "crapload" implies that each individual tennis ball is actually worthless on it's own. Where the vat is big, "crapload" serves to color the sentence. Unfortunately "crapload" is unprofessional. "A lot" is just colorless. Suggestions?


I'm looking for a phrase like "transcendental language", but meaning eloquent rather than other-worldly. In particular, I want to refer to a [literary] sketch as "_ language". This sketch is A Gotham Reverie by Fanny Fern, in which a prostitute is referred to [revealed as a prostitute] in very abstract terms, such as "her name was Magdalen" (I'm paraphrasing), "her own unrelenting, unforgiving sex", etc.


Yet another a part of Circular Staircase, by Mary Rinehart: "Not out in the hall!" she gasped; "Oh, Miss Rachel, not out in the hall!" trying to hold me back. But I am a large woman and Liddy is small. We got to the door, somehow, and Liddy held a brass andiron, which it was all she could do to lift, let alone brain anybody with. I listened, and, hearing nothing, opened the door a little and peered into the hall. Are any words omitted in the sentence that includes let alone brain anybody with? Something looks missing from this sentence.


It is well known, that a human being can not imagine new colors which are not obtainable by just combining the already known ones (red, green and blue). Actually I can draw parallels to physics and may ask you: Imagine a new physical quantity, which you must not obtain from simply combining any of the already known ones and without using anything you have ever experienced in your live. But how would you find a new physical dimension, which you have never experienced in any way? Wouldn't this be like to imagine a new color? Are we thus somehow bound to never know everything, not because we have too little time or possibilities, but because it literally lies beyond our imagination? insert dramatic music


Please have a look at this sentence: "Multiple citations of my work during the short time since their publication indicate its quality." Here work is referring to many publications. I have a tough time reviewing a statement particularly because of this sentence. Is this sentence grammatically correct? I mean are "their" and "its" used correctly here? Should it be "... indicate their quality"? But that's not right because of work?! How about "works"?! The mix of "their" and "its" is very confusing.


I'm reading a book on description logic and I found white and black squares at the end of some paragraphs. I would think they stand for Q.E.D., but since there are two types used in one book, I believe the black square states for something else. What could it be? Is there some convention for it? (I checked and there is no list with explanation of symbols used in the book).


For rental agencies and companies, the cars owned would be a fleet. Several cars escorting a VIP would be a motorcade. However, what if I want to say: I dislike being the lone driver in an empty stretch of highway, so I may end up speeding to get from the [group of cars] behind me to the [group of cars] in front. Is there a good collective noun that would apply to this situation? Or would it be a matter of choosing a general term, like group, cluster, block etc.


Working with Kirchhoff's rules, I am attempting to device an algorithmic approach to finding the unknowns of the problems, I am of a Computer Science background and I am finding it difficult to identify proper closed loops within the circuit and I am curious if there is a generalized pice of sudo code applicable to these problems, or perhaps a matlab or sympy script available?


Although I feel the answer to the following question is negative, I can't get any precise results neither find anything to read. The question is: Would a complete oracle from some level of arithmetical hierarchy anyhow boost the complexity classes, in terms of complexity? For example, would a P machine with halting problem oracle be able to solve anything from EXPTIME? Or LOGSPACE machine with the same oracle to solve something from PSPACE? Thank you.


This is something that has always bugged me. I am never sure where to place the question mark, or whether to place it at all when the end of the sentence does not finish with a question, or a number of questions from the begining For example: The question nagging me is to what extent can we encapsulate all what we observe in nature into a set of simple computational rules, within which we can leverage our existing knowledge. Should the final full-stop (period) be replaced by a question mark? Or perhaps even the comma?


I'm interested in the size of atoms (extent of the outermost electron cloud), in particular its cross-sectional area and how it scales by increasing Z. (I trust that this won't be affected much by the number of neutrons?) I recognize that for a given atom/ion one can simply look up the data, but I'm interested in a more 'first-principles' kind of view. The distances of electrons in given orbitals is not constant across different atoms, since as the nucleus gains protons the orbitals tend to get crushed somewhat closer I believe. (In fact my final goal will be to determine scattering for charged particles, which is based on much more than the geometry, but I became interested in this particular subproblem apart from that ultimate question.)


Usually when I read about AdS/CFT complementarity as a particular case of the Holographic principle, it suggests that physics evolution on a boundary has a map to physics evolution on the bulk. But what of sort of boundaries does this apply? I've usually seen it applied where the event horizon is the boundary and the outside space is the bulk. But does it hold for imaginary boundaries as well, like the typical Gaussian surfaces one consider to study Maxwell equations as well? If not, what special properties needs to satisfy the boundary so that the holographic principle holds?


Possible Duplicate: Set table position to top My document (book) has text and floats. There is not enough text, so that all floats can be placed before the text finishes. Then pdfLaTeX puts the remaining float right in the middle of an otherwise empty page. This does not look good. Is there a way to position these floats at the top of the page instead in the middle? Placement specifiers are already given [t]. Also combinations of [h,t,!,H] don't help.


Possible Duplicate: What do you call words that look like a negation but are not? I found these poor orphaned words that only exist through the life-giving quality of their affix: feckless, ruthless, unruly, inept, dishevelled, dismayed, disgruntled I'm sure there are more. They have the familiar appearance of antonyms... Antonyms to something that doesn't exist. It's as if they've lost their positive attitude. Do these words have a common name? How did they get this way? They all have standard english affixes with known meaning, so it seems like they should be able to stand on their own. Were the original words lost? Is there a list of these recognized words somewhere?


When my hair gets long I start doing a little flick of my head occasionally to get my hair out of my eyes. This grows into a habit though, and for the first few days after cutting my hair I end up doing to same action. Interestingly enough when I have short hair I feel physical pain. How come the same action hurts when I have short hair, but feels completely natural when my hair is long?


Possible Duplicate: Maxwell's Demon Constant (information-energy equivalence) I was reading: Demonic device converts information to energy : Experiment inspired by a paradox tempts a bead uphill. Its good to see conservation of energy is violated. :) I want to know more about it. What other resources are available (that doesn't involve too much math). Especially, I want to see that beed experiment. Are there any demonstrations available on net? EDIT: I did learn more about maxwell's daemon from this:


Does corona discharge charged insulator? I draw a diagram to make it simpler to understand. Electrons form negative side is accelerated due to electric field and accumulate on insulator surface. Gas on the positive side was ionize giving off electrons and flow to positive terminal. Am I understanding this correctly, When I place plastic sheet between HV terminals and when I remove plastic sheet I got an electric shock, so I think corona discharge might charge plastic sheet.


Possible Duplicate: How to preserve hyperlinks in included pdf? After I merge PDF documents with pdflatex and pdfpages as described here, the URL-s are either broken (PDF files from OpenOffice), or their colorbox is missing (hyperref), or if they span over two lines only the information from the first line is kept (the original PDF was correct). Can this be fixed? Or is it a known issue?


I'm using memoir class to write a novel. As it is widely known, writer comments inside novel characters' dialogues are usually enclosed between long dashes which in turn are written as a triple dash in LaTeX. However I'm experiencing trouble when those long dashes (which always follow or precede a word with no space between) are near a linebreak: breaking word is not hyphenated most of the time and thus the line exceed the break margin. How can this be fixed?


I'm writing a scene in which I wish to describe a typical street beggar - his way of dressing in particular. Check for example such a dude as the one below I could use descriptions such as: snobbish, dirty, bizarre, rugged, barbaric, etc but feel those are not adequate to building a picture of a beggar in the minds of my readers. I want words that would describe a sort of beggar that typically, you'd wish to avoid - one very pitiful, but also repugnant? What words or phrases would you use for such a description?


I just played a game from the start to the end of main story, there are many other challenges in the game left untouched, so I think I can't say 'game completed', can I? I know the following possible candidates 'completed' 'ended' 'walked through' 'cleared'(well, in Japan they use this word) But I'm not satisfied with these ones, what is(are) the right word(s) to describe that I have seen the outro of a game? Thanks in advance.


While it is fairly established that both fast movement and the presence of gravity make time pass slower as compared to a system at rest / free of gravity, does that mean that there is no way for time to pass faster than in vacuum, or does general relativity also have "faster" metrics? To be more precise, is there any frame into which one could go for a while, and on returning to vacuum less time would have passed there?


Some of the distant galaxies appear to be receding from us faster than the speed of light due to stretch of the space between us and those galaxies. By an analogy with the ant on a rope paradox, the light emitted from those galaxies can actually reach us. Is it true that, at one point of time, those galaxies suddenly disappear from our view, and then after sufficiently large times (which may be more than the lifetime of the universe), they come into view again? And by the same reasoning, would more previously hidden galaxies will become visible at some time?


Hello I am new to operational research and would like help classify the following transport problem. I have a model which simulates a taxi like service, it a has a range of inputs that can be changed (no. vehicles, starting times, vehicle capacity etc) and then the model spits out a set of outputs (time spent idol, time spent travelling with passengers, time passengers spend waiting) which I apply some kind of associated cost to both the inputs and the outputs. What kind of techniques would you apply to this problem so that I can minimise the total cost? I imagine some algorithm would iteratively run the model and adjust the inputs and measure the outputs to form the data. However this is just my uneducated guess.


I read the "Catcher in the rye" and I found it difficult book for not native reader (Compared to for example Steve Jobs biography. There is a lot of guessing what the author means by particular sentence. Context : "Her mother belonged to the same club we did," I said. "I used to caddy once in a while, just to make some dough. I caddy'd for her mother a couple of times. She went around in about a hundred and seventy, for nine holes." I wonder what the main character refer to by : She went around in about a hundred and seventy, for nine holes. Are the numbers refer to numbers in golf? What does : "Go around" means here ?


As I understood, we choose to mark the current with arrows going from the plus pole to the minus pole (even though we know that in reality it is the contrary). As I'm looking at electric circuits, I notice that arrows for generators are going from the minus pole to the plus pole, and that for resistors it is the contrary (for the voltage) How do someone determine the direction of voltage arrows in a circuit? Is there a physical reason to choose a direction or the other? If, for example, I choose to use the red notation to mark my circuit, what's the reason behind this? Giving one notation for the generator, how am I supposed to mark my resistor?


When I use the calculator to get the result of this integral I get a decimal number. However, in my calculus book, as shown on the picture, the answer was represented using some trig symbols! Is there is a way to show the same result, but not in decimal only? I want to use symbols like pi or sin to represent my answer. Just like my book. could it be done using the calculator?


There are many different types of fields such as electron field, magnetic field, higgs field, electric field, quarks field etc, my question is do these fields interact directly with each other? Particle can form when the field becomes excited and different particles may interact with each other directly. Electric field and magnetic field are interacting with one another to become photon right? Or photon is the excitation of electromagnetic field which is a standalone field from others?


Certain disciplines, generally called pseudosciences, falsely claim that they make actionable truthful statements about observable objective reality. Examples are astrology, homeopathy, psychiatry. How would you call a sincere practitioner (not a researcher/populariser) of such a discipline? Not "charlatan" - the perpetrator is as deluded as the victim. Not "pseudo-scientist" - just like a practicing surgeon would not be called a "scientist": this term seems to imply "original contribution" to the discipline as opposed to simply "plying the trade".


Is there strong supporting evidence of discrete electron shells or orbitals surrounding atomic nuclei? I realize the math works out and we have energy frequencies emitted, perhaps even atomic diameter measurements. But these still seem indirect and allow for other possible explanations. Is there direct experimental evidence for these? The orbitals concept is always shown almost as fact, not theory, so wondering what experiments must support such strong conclusions and don't mention any other alternatives?


I'm a pretty bad fellow myself,' the stranger remarked, 'but Macfarlane is the boy - Toddy Macfarlane I call him. Toddy, order your friend another glass.' Or it might be, 'Toddy, you jump up and shut the door.' 'Toddy hates me,' he said again. 'Oh yes, Toddy, you do!' The extract is taken from the Body Snatcher by Robert L. Stevenson. Toddy seems to be just a name, but this word may insinuate another meaning in the above situations. And Macfarlane is the boy, which means he is 'worse' than the speaker?


I was looking for a characterization of the dimension of an nvs using Heine Borel theorem. suppose i have a Compact operator between an Hilbert space and itself, i want to proof that the autospace generated by the eigenvectors associated to one eigenvalues (i'll call it A_L) is finite dimensional. I know from the previous theorems and lemmas that A_L is closed, now my question is: if i show that the orthonormal base of A_L is bounded, precompact therefore compact, is it finite dimension?


I want to compare the time that it takes to slide a particle in a frictionless hypocycloid curve, so time would be given by the arclength divided by the velocity So I need first compute the arclength of the hypocycloid curve, but in general the arclength is given by And by conservation of energy, velocity is given by Substituting in the integral results Solving the indefinite integral results in So now I would just substitute the function y corresponding to the hypocycloid curve Is my reasoning right? Then finally to compare times I would just make a graph of the time functions corresponding to the brachistochrone and the hypocycloid


I know how to prove that the Riemann integral of a function does not change if one point of the function is changed. However, extending that result to a finite set by use of induction is something I have struggled to prove. I just need a hint as to how I should start off the proof. Looking forward to an exchange of ideas. An answer I found for a single point is given below.


Here is a literally-quoted passage from Martyrs in Paradise: Woman of Mass Destruction by Terry Reese Downing: "How nice of you. And thank you," she again was appreciative. "My pleasure. Go back to rest and sleep. Let me know if you needed something and don't hesitate to wake me up," he told her. Is the use of past tense common in these kind of contexts? Does the use of past here get the point across in a less direct way?


I would like to express, in one word, the tendency to concentrate excessively rather than disperse. This is applied in a sentence where I describe a set of data, which has too much focus on one aspect and miss out on other aspects. For this I use the word "constringences". The results collected and presented earlier are limited by ambiguities, paradoxes and constringences. However, it seems some dictionaries do not know constringence, while others do. So is it a word or isn't it?


I read the following sentence in a newspaper about a restaurateur's reasons for abolishing tipping: "Many of the owners other reasons sound like the typical complaints of British tourists, who are perpetually confused by whom to pay and how much." "By" preceding the use of "whom" does not sound right to me. For me the word "by" introduces the performer of an action, whereas I always thought "whom" refers to an object. This must be good English as it was in reputable newspaper, so can anyone explain how this makes sense?


I'm trying to find a way to describe improving the Signal to Noise ratio of a communication/message succinctly. Using the entire phrase over and over gets clunky. Phrases that are close, but don't have as much of a technical connotation as I would like: "Tuning" as in tuning a radio "Demunge," but it implies the message is scrambled, and I think it's programmer jargon anyway


Common phrases are draw drapes or shades, draw a bath (pull water?), draw a conclusion (out of someone) and other uses of pull. Why does draw mean pull? It becomes confusing when something that had a visualizable meaning - pulling drapes across a window - has been extended to something that does not make sense - turning Venetian blinds from the open position to closed position. How did this happen?


Is there an english word fitting the longer description 'the visible part of something as seen right now' or 'the thing as it can be understood as of this time'? The word 'Impression' seems to cover this somewhat, but it has the added baggage of being someones opinion, rather than describing the factual state something has, as well as having a different meaning of being a physical depression of an object on another object. Is there an alternative?


I want to produce two versions of a book, one with footnotes and the other with endnotes. I'm using the endnote package to convert the footnotes to endnotes to produce the second version. But I need to alter the text on the heading and get the headers on each page to look the same for the endnotes as the other chapters in the book. For example, currently the heading says "Notes", say I wish to change this to "Myheading which is underlined" and then have "something else" appear in the headers of the pages on which the endnotes themselves appear. Is there a simple way to do this? Thanks


From a Bibtex file I want to create a References section where each reference has its own abstract. For the abstract, I'm using abstract.bst mentioned in another question. I am using Lyx. When I generate the bookmarks, it only references the start of the References section. This is no good because I want to able to skim the abstracts and also have the document in a printable/shareable form. How do I generate the bookmarks with a bibtex file such that it creates a bookmark for each reference? Also, I don't consider this question Lyx-specific.


Find one possible pair of values for x and y. If x,y and x-y are two-digit numbers. x is a square number, y is a cube number and x-y is a prime number. Is it as easy as I am thinking it is? Or I am trying to complicate things by looking for the equations here. The simplest way I can see is to write down all these two-digit numbers and then choose on possible option. But, is it??


Edited version. If an electrical charge like a lightning bolt seeks ground (think of a lightning's rod's purpose), and if all matter is seeking ground (gravitational pull), and if all energy and all matter are various forms of vibration (electromagnetic spectrum), what is the likelihood that all forms of energy are directly or at least indirectly also seeking ground? I'm just looking for an energy's basic common behaviors with other energy (and matter) Specifically I'm thinking of mechanical (vibrational) energy once it attaches itself to an object. Thanks,


Every algorithm I've found so far begins by computing st numberings, which in turn requires a biconnected graph in order to work with an arbitrary vertex pair (s, t). In the following graph, edges [A, B], [F, G] and [H, I] violate the i < j < k property of an st numbering: https://i.stack.imgur.com/XQmju.png It can obviously be planar, but how is the embedding computed?


Is this double/triple negative grammatically sound? Ordered operations require that space on disk is allocated sequentially, so spatial ordering corresponds to chronology of operations, but actual disk writes need not to be neither atomic nor ordered. Explanation: Words neither and nor emphasize on the fact that both conditions are (independently) allowed to remain unsatisfied, that both are optional. To be more formal, "need not be atomic and need not be ordered". But then again, it becomes a concoction of two negations joined by a conjunction.


G is a given sphere in the space. For any line e that has no common point with G, define the line f as the conjugate of e with respect to G if f joins the points of tangency on the two planes tangent to G passing through e. Show that two lines of the space passing G are skew if and only if their conjugates with respect to G are skew.


Let's says there is a fundamental particle: That is so massive that it is a black hole by itself (Compton wavelength < Schwarzschild radius) That carries a conserved quantum number (e.g. charge of an exotic interaction) which no lighter particle carries Would it be able to emit Hawking radiation? If not, does it contradict with the classical arguments (entropy analogy, pair creation at the horizon etc.) regarding the origin of Hawking radiation?


I am a programmer and I am doing a camera simulation, I am stuck in a matter of how to know where arrives every ray of light after traveling through the lens and being refracted. Every point of the object gives an infinite number of rays, but in my simulation I will take five random rays to trace from every point from the object. The rays from one point of the object should also come to one point on the film. How can I know this specific point on the film for each point from the object? Hope to find some help here about this problem.


I'm going to start a degree course in physics next year. So far in high school I covered some physics without calculus. I know that I will start everything from the beginning at university, but I would like to prepare in some ways. Then the question is: what should I do? Should I revise what I studied? Should I go head? Can you suggest (from your experience) what should I do before starting a physics degree course? PS In case you recommend to study some material, can you suggest a book?


There are so many books teaching how to take derivative and integration of a function. I think I'm good enough (enough for me lol) in those parts, my problem is that I can't start solving a question and even don't know where to start (finding or making the correct function or equation, kind of calculus applications in area, volume, etc.) - what should I do? Plus I wanna know if there is a good syntax in calculus; like if I should write constants and variables in a special way (capital, small, etc.), so that my writing is more readable and clean?


This question is quite specific but I am not sure which verb tense I should use when committing/checking in code. If I fix a bug and checking in the code, should I write: Fixes bug on feature A Fixed bug on feature A I always use past tense because the bug was fixed before I check in but it looks a bit strange when I look at file history. Should I use one over the other and why?


I'm writing a short bio of my character who has made a contract with a demon and is now required to do her bidding. He's not necessarily a slave, he still has the freedom to do whatever he likes, I guess it's kind of like a DnD warlock-patron type of relationship where she occasionally has tasks for him to do and he's bound by contract to complete them. The sentence I'm writing is like "[Character] made a contract with the demon [Demon Name] and is now [word or phrase I can't think of] to her bidding." I swear there's just a single word for it (I keep thinking of words like "vulnerable" and "liable" but they're not really right), not a phrase (though if you can think of one that fits then I might end up using it if I can't figure out the word), and it feels like it's on the tip of my tongue but I can't remember it at all and it's killing me.


Is there a standard, formal or defacto, for what exactly a TeX distribution is and what programs/features need to be supported to be a TeX distribution? I feel like this question has had to have been asked before, and while my searching turned up a number of similar questions none got at the heart of what I was after. For context, I'm trying to understand what TeX and LaTeX are from a software point of view. I've been using TeX/LaTeX for years via the pdflatex command or indirectly via pandoc but I've never really had a good feeling for what, exactly, I'm installing when I install a TeX distribution. For example, right now on my Mac I have a pdflatex command that's located at /Library/TeX/texbin/pdflatex and the /Library/TeX/texbin/ folder has a few hundred binaries in it. So is a TeX distribution just folks deciding which of these programs to make available? Or is there more to it than that? Put another way: If I wanted to create a new nominal TeX distribution (which, trust me, I don't) what exactly would I be doing/have to do? I realize this is a pretty big question with answers that could have varying levels of detail. If the answer is RTFM that's legit -- but I'd appreciate a pointer to which part of which manual I want to be reading.


I'm feeling kind of stumped on this, even though I think I know the answer. If I had written this sentence, I would just rephrase it to avoid the issue, but I came across it and found myself wondering. The sentence: "All that stuff like cars and planes is releasing carbon dioxide." At first glance, it seemed wrong and I immediately thought it should be using "are" instead of "is". But then I stopped and thought about it and realized that it's likely correct, since the sentence would be "All that stuff is releasing carbon dioxide", which is correct, if I took out the examples. It just sounds really awkward and wrong the way it is. Is there any grammatical rule that would justify using "are" in this context? Would it make a difference if the list was longer, like if the sentence was "All that stuff like cars, planes, and factories is/are releasing carbon dioxide"? Or is just a correct grammatical sentence that sounds bad?


My question: What is Happening During Particle Collisions if Particle Location is Defined by a Wave Function? From my understanding, we can define particle location by a probabilistic wave function from Schrodinger's equation. So the particle doesn't exist in one exact spot naturally. So what actually happens then when two particles "collide" (which does seem to imply a single location of contact, at least in classical mechanics)? My guess would be it counts as being "measured" and the wave function collapses to a single location for each particle, but I'm unsure what interaction between the particles would cause it to count as a "measurement" (measurement might be the wrong word but I don't know a more generic term for this). Maybe I'm not fully grasping wave-particle duality here in this specific case. Any help would be appreciated.


I would like to buy a book to study multivariable calculus. Currently, the texts I have in mind are: Vector Calculus, Linear Algebra, and Differential Forms A Unified Approach by Hubbard & Hubbard Multivariable Calculus with Applications by Lax & Terrell Functions of Several Real Variables by Moskowitz & Paliogiannis I want a book that has a clear expositions of the subjects of multivariable calculus. Also, I would like a book that avoids leaving proofs as excercises to the reader, or at least that does not do it most of the time. If possible, a book that also contains multiple examples/exercises with (fully) detailed explanations/solutions to at least some of the examples/exercises. I do not mind a rigorous approach to the subject as long as the content is explained with detail. Which of the books mentioned above fits best the description? Also, if you have other books in mind, feel free to recommend them as well. Thanks in advance! Note: I have taken two proof-based calculus classes and one proof-based linear algebra class.


I always assumed that the word censorious meant someone or something that is given to censorship. Like if you say that a community, an organization, or a person is overly-censorious, that means they frequently or unnecessarily censor content. But I just looked up the word in my favorite dictionary and found that censorious has a different meaning than what I thought: censorious Addicted to censure and scolding; apt to blame or condemn; severe in making remarks on others, or on their writings or manners. Implying or expressing censure. So, a censorious person is not a person who is quick to censor. Too bad, because I thought that was a useful word! Is there an actual word that means "being given to excessive censorship"? Example: I might criticize a film distributor as being _____ because they often censor controversial content whenever they release a new edition of a classic film.


Everything I can find says that time dilation approaches infinity at the event horizon of a black hole. Black holes evaporate over a finite amount of time. Wouldn't this imply that somebody falling into a black hole would eventually just see the event horizon shrink away from them as fast as they fall into it. This seems to imply that its impossible for anything to fall past the event horizon, everything just gets very close to the event horizon and then the black hole evaporates from underneath them. Ive read through as many posts as I could find addressing this. The most direct one being this one: https://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/fall_in.html In all the posts that claim to have a definite answer I don't understand it. And all the posts I feel like I understand don't claim a definite answer.


In the Wikipedia page for the Ising Model it is written without citations: One of Democritus' arguments in support of atomism was that atoms naturally explain the sharp phase boundaries observed in materials[citation needed], as when ice melts to water or water turns to steam. My question is: Is this statement historically accurate? If so, did Democritus have an argument or explained his intuition on how exactly atoms explain sharp phase transitions? A related question, would be how this relates to a a modern statistical mechanics viewpoint and If one really needs an atomistic description: From a continuous model of matter like a classical field theory, could one arrive at a first order phase transition from first principles? I know you could just 'artificially' impose a phase transition, but I'm thinking of a procedure like taking the large-scale limit of a classical field theory and arriving at a new theory with phase transitions.


I am working on TeXmaker and all of the sudden this message popped up (this problem occured after closing and re-opening the program and the code is correct, there i no error inside of it). I tried to run the same code on TeXstudio but it gave me the same problem. I tried to search everywhere in the internet to see if there was a similar cases, but all of theme were useless or not exactly like mine. I get the same message also for older files and new ones. This makes me guess that this is a problem of MiKTeX since it doesn't compile neither on TexMaker and TeXstudio. I tried to use the command prompt as suggested on reddit (I wrote "pdflatex filename"), but I really don't know how to exploit this feature. Do you have any idea of what could cause this problem?


I am learning about EM waves and am getting confused. Here is a picture from an intro. textbook I am using. Looking at this, it is clear that both E and B are perpendicular to the direction of motion, and all is fine. However, let's say the wave was propagating at an angle theta to the z axis. In this case, you can still draw the E and B field perpendicular to the direction of motion (with E in the same plane as the direction of motion and B perpendicular to the plane of motion as in the picture), but now there would be a component of the E field that is in the direction of z, even though the E field is still perpendicular. In this case, why wouldn't the EM wave propagate with this longitude component? What am I missing here? Here's a crappy picture of what I mean: In the picture you see that the wave is propagating in a direction with a non-zero x and z component and clearly the E field also has nonzero components in the x and z direction, so wouldn't these components be "longitudinal waves" as they are propagating in the direction of motion?


Most explanations of the integer quantum Hall effect start out in the grand canonical ensemble, where the plateaus arise when the chemical potential (or equivalently the Fermi energy) is in the gaps between the Landau levels. However, they then usually continue with a statement that working at fixed chemical potential is actually imprecise as the system is in a canonical ensemble (i.e. fixed particle number,) and so we need to include disorder to get the plateaus. While I understand why disorder is needed if we work at fixed particle number, I don't understand why the experimental systems are assumed to be in the canonical ensemble to begin with. Don't electrons flow in/out of the material when you measure resistivity? If this is the case, why is working in the canonical ensemble justified?


In set theory, the notions of set and membership are considered primitive. We only specify some of the properties that we think our primitive notions have using the axioms. Usually, the very first axiom of set theory is the axiom of extensionality which specifies that two sets are equal if and only if they have the same members. My discomfort with specifying this axiom as the first is that we haven't said anything about how the notion of membership relates to the notion of set in any previous axiom. That is we haven't specified that it makes sense to say something is a member of a set. Yet we use this notion in the axiom of extensionality. Why we don't have an axiom that exclusively talks about the membership of things in a set?


I have been searching for an automatic method (a computer program) to evaluate any first-order logic (FOL) formula given some knowledge base. The most common approach to do this is to use PROLOG. The issue with PROLOG is that it employs a subset of FOL which, for example, restricts the use of quantifiers. When searching about this, I have learned that PROLOG uses the resolution algorithm, which requires formulae to be in Conjunctive Normal Form (CNF). I have also learned that there is a process called Skolemnization that can be used to remove the quantifiers from a formula and help convert it into CNF. Therefore, my question is the following: Can the resolution algorithm be applied to any FOL formula? By this, I mean if there exists some algorithm that takes as input any FOL formula and normalizes it (using skolemnization and other methods) into CNF so that resolution can be applied to it?


To "empathize" with someone means to "understand and share the feelings of another" (Oxford dictionary). In science fiction, an "empath" is "a person with the paranormal ability to perceive the mental or emotional state of another individual." (Oxford dictionary) Is there a word to describe the "opposite" (behaviour in nature, not antonym) of an "empath" - someone who can communicate in such a manner that it is very easy to empathize with them because you can easily understand or recognize the feelings behind what they are saying? More details: As pointed out above, an "empath" has the ability to perceive the mental or emotional state of another individual. I am seeking a word (if it exists) that describes the ability to communicate in such a manner as to "create a mental or emotional state" - an emotional connect - to make others more easily relate and empathise with them. (Something that most story tellers do effectively). (Some commenter thinks my question is about Sci Fi. No, I am just looking for a word to describe something in plain English. But it doesn't matter if it is an uncommon and rare word from old English or even a modern slang).


The second law of thermodynamics states that the entropy of the universe increases over time and this has lead to theories like the heat death of the universe and the big rip. What this means in effect is that all matter and energy has an expiration date, beyond which it gets divided accross infinite space and this is irreversable since entropy does not move backwards. The first law of thermodynamics states that energy cannot be created or destroyed. The only explanation this leaves for the universe's existence is that energy has existed since always and never had to be created. And herein lies the contradiction: If energy has been around for an infinite amount of time, why hasn't the heat death or the big rip already taken place? How come we are able to observe the universe in its current fairly organized transitional state unless A. energy was created a finite amount of time ago or B. Energy has existed since always but it can freeze or move backwards entropy-wise allowing us to observe it in its current form. Either way one of the two laws is violated. How do physicists reconcile this paradox?


The other day I wasn't feeling so well so I visited a doctor. He recommended that I take a break and get intravenous therapy so I did. I laid on a bed and the nurse inserted a needle into my left arm which was connected to the pack of liquid containing vitamins. I soon fell asleep. More than half an hour later I woke up. The pack was practically empty. However blood was slowly flowing out of my vein. I frantically called the nurse, who apologized for not catching it earlier. I thought the sole factor that delivers the fluid to my body was gravity, since the pack is hung in the air much higher than my arm. But given that the direction of flow reversed once the pack was emptied, my assumption is probably false. My new theory is that the vitamins are delivered because the pack's pressure is higher than my vein's when there is enough liquid in the pack. However this still doesn't explain why I started losing blood as when the two sides' pressure reaches parity all movement should stop. Since the pack's initial pressure was higher, There should be no change of direction until reaching equilibrium. Why did I lose blood and are there any precautions I can take to prevent this incident in the future?


Many elementary explanations of the Einstein-Lorentz transformation derive it using Einstein's special relativity postulates, combined with some thought experiments considering light sources and observers. However, I have read that these thought experiments often do not hold when subject to rigorous mathematical scrutiny, and that Einstein himself did not use them when making his arguments. Further, it is obvious that Lorentz did not use Einstein's postulates when deriving his transformation because at that time he did not trust in Einstein's postulates. Rather, from what I have read, the actually rigorous way that the transformations were derived is using more complicated math such as hyperbolic geometry. I cannot seem to find a good resource that walks through the derivation in a rigorous way; especially one that does not assume prior knowledge and explains the math being used. Can someone please either provide a rigorous derivation here, or point me to a good resource for me to find it? I am especially interested in learning the approaches of both Einstein and Lorentz.


I have two rectangles of different sizes side by side. I want to scale them both (each maintaining their original aspect ratio) so they each end up with the same height and together equal a specified, fixed width. I would like to find a formula that will work no matter what the sizes of the rectangles are (some may be bigger than the target width, some may be smaller - thus some will have to be scaled up and some down). I found what appears to be a very similar question here, however the only solution provided seemed to imply a universal scaling factor. That doesn't work for my situation because the rectangles need independent scaling. I am also only scaling two rectangles instead of three, and the resulting widths of my rectangles must together add up to a specific width (the other question just didn't want to exceed one). Any help would be incredibly appreciated.


I'm reading Carroll's GR book. I'm able to follow it for the most part, but a couple of paragraphs are a bit hard to decipher: According to the WEP, the gravitational mass of the hydrogen atom is therefore less than the sum of the masses of its constituents; the gravitational field couples to electromagnetism (which holds the atom together) in exactly the right way to make the gravitational mass come out right. What exactly does "couples to" mean? Right now that's just a vague phrase to me that implies gravitational field has something to do with EM - but what's the precise notion behind it? Sometimes a distinction is drawn between "gravitational laws of physics" and "nongravitational laws of physics," and the EEP is defined to apply only to the latter. Then the Strong Equivalence Principle (SEP) is defined to include all of the laws of physics, gravitational and otherwise. A theory that violated the SEP but not the EEP would be one in which the gravitational binding energy did not contribute equally to the inertial and gravitational mass of a body; thus, for example, test particles with appreciable self-gravity (to the extent that such a concept makes sense) could fall along different trajectories than lighter particles. I have no idea what the statement in bold means at all. Could anyone please explain this so that a layman like me could understand?


As we know, the recent Nobel prize was awarded for the creation of attosecond light pulses. I read this excellent answer, describing both how the pulses are created and what applications they have. I understand how the pulses are created by the addition of waves with harmonic frequencies in a classical sense. However, from a quantum mechanical point of the view, light comes as photons with quantised energy, with the energy of each photon related to its frequency. As the attosecond pulses consist of many frequencies, I wonder how they relate to photons. My guess would be that the attosecond wave describes the probability of detecting a photon at a particular location/time, but that the photon detected can have the energy corresponding to any of the constituent frequencies. Is that a correct guess, or is that too simplistic? When we detect individual photons of the attosecond pulse, what frequencies can they have?


First, let me acknowledge there are numerous posts on this question already. The most pertinent to my specific question is probably this one. To restate the problem: "A family has two children. Find the probability that both children are girls, given that at least one of the two is a girl who was born in winter." The solution offered in the text includes this step: "use the fact that {both girls, at least one winter girl} is the same event as {both girls, at least one winter child}". This subtle shift is necessary to reach the correct answer. But it seems to come out of nowhere, right? I wonder if the change was motivated by a desire to be able to invoke independence. Since {both girls} and {at least one is a winter girl} are clearly not independent, while {both girls} and {at least one winter child} are. Hard to get inside the author's head, but that's my best guess. What do you all think?


There are various threads on this site explaining the mathematical details of how, in QFT, position operators are non-relativistic. I can follow some of the math, while some of it goes over my head. But even with the parts of the math I can follow, I have a hard time relating it to anything conceptual -- that is, all the mathematical explanations I've seen have a feel similar to proofs by contradiction in that they show that it's true there are no relativistic position operators, but not why it's true. So, to be clear, what I'm looking for isn't a nonmathematical explanation necessarily, but just an explanation that feels like more than just a bunch of algebraic manipulations -- something that connects all those calculations to the actual objects we're trying to model and their properties. To clarify what specifically I'm confused about, I don't get why bringing in special relativity should mess up the notion of position at all. I understand that position is a relative property, so that if we change reference frames any position operator would be affected. But momentum and energy are also relative, and yet there doesn't seem to be any issue with defining relativistic versions of their operators. What makes position so different that we can't just define it in some given reference frame and apply the Lorentz transform as needed? Does it have something to do with the geometry of spacetime being hyperbolic?


I've read several threads over the past several days talking about how photons don't have wavefunctions in the same way as massive particles do because they don't have non-relativistic limits. If I understood correctly, that's because the usual position operator introduced in introductory QM courses really only applies to non-relativistic theories. The Newton-Wigner operators kept being mentioned as the closest QFT analog to the position operator from non-relativistic QM, so I've been trying to find information on them, but the relevant Wikipedia page is very sparse and vague and everything else I found was very long and technical. All I really want to know is: What's the actual definition of the Newton-Wigner operators? How does it differ from the definition of the position operator from non-relativistic QM? From what little the Wikipedia article did say, I know the Newton-Wigner operators aren't Lorentz covariant, which, if I understand correctly, means they're reference-framed dependent w.r.t. the Lorentz transform. But is that the only difference between them and analogous operator from non-relativistic QM? If so, then why does position in particular often get singled out as being different in relativistic and non-relativistic QM and QFT, when other properties, such as energy and momentum, are also reference frame dependent?


As a caveat, i am not a mathematician but rather a programmer with an amateur interest in patterns, fractals, sequences, data science. That said, i have been following recent developments in aperiodic tiling with interest. I've had an idea for an application for it, but I don't know enough in the field of mathematics to know if: It's obvious, been done, move on It's an interesting idea worth exploring, or It'll never work or be useful, just stop now. The thought is as follows: By definition, aperiodic monotiles don't repeat on the plane, therefore They are effectively a visual representation of an infinite, non repeating sequence. They can be computed relatively easily (e.g. see here), and the next tile can be calculated based on the position of the previous one. Therefore, you effectively have a pseudorandom number sequence, given a seed of the coordinates to start at. Is this worth exploring, or just a rabbit hole leading to a dead end?


Consider a sample of an ideal gas kept in a pouch of some volume. This pouch is then kept in a bigger container of volume V. As soon as we open the pouch then the gas will expand irreversibly in the container. Also consider that this expansion is adiabatic in nature and no energy flows in or out of the container. If we let the system be kept isolated for a sufficient amount of time in which it approximately achieves steady state, then can we say that in this steady state condition every molecule in the gas sample will approximately have the same speed? I thought that the entropy of the system would be maximum in this configuration as the energy is tending to be spread out equally among all molecules. Is this notion of entropy being a measure of the distribution of energy logically correct? Also if it is not correct then is there any mathematical way to find the distribution of the molecular speed of the gas sample?


I would like to know if there are any books on combinatorics and number theory that follow an axiomatic approach akin to that of Sierpinski's General Topology. I have found some books for both subjects that might follow this axiomatic approach but they aren't explicit about it. The books I am referring to are: Aigner's Combinatorial Theory, which one user on Amazon said follows an algebraic approach but I don't know if that is equivalent to an axiomatic approach. Landau's Elementary Number Theory, with the author having written an axiomatic book on Analysis called Foundations of Analysis, which I have a suspicion might be axiomatic. And Sierpinski's Elementary Theory of Numbers by the author I mentioned above with my suspicion being that it also follows an axiomatic approach. I have scoured the internet for such books but to no avail. I haven't found posts on stack exchange that address this question, specifically for number theory and combinatorics, either so I decided to write one myself. I really hope someone here might have found such books. More specifically Brualdi's book on combinatorics states that the multiplication principle is a consequence of the addition principle while Vinogradov's number theory book states that division with remainder is a generalization of the quotient of two integers. I would like the books to follow such an approach, stating what is essential and deriving everything else logically. I don't think I can be any more specific but I hope you get the gist of what I am saying.


This is probably a really common word and I'm having a moment, but it occurred to me the other day that I can't think of the verb that describes the action of sweeping a knife across a pat of butter, which has the effect of scraping butter from the pat onto the knife. It's kind of the opposite of "spreading"; i.e., the action to deposit butter from the knife to the bread/toast/whatever. "Scraping", I suppose, is close...but it doesn't feel right. Intuitively, I feel like scraping involves a fair amount of effort to remove the surface layer, which is usually hard, contrary to the properties of butter at room temperature. "Peeling" or "paring", perhaps, but again I'm not convinced: butter doesn't have a peel and paring is more of a cutting action. The artefact of the process is a "curl of butter", so maybe "curling", but I've never heard that used in this way.


Suppose two particles A and B collide. Consider the position vs time plot of the trajectories of A and B, shown in green and red in the following diagram. The two trajectories "meet" at coordinates (x', t') indicating collision, although according to the Pauli exclusion principle, two particles cannot be at the same position at the same time. Now, it is clear that the trajectories A and B are continuous and differentiable, indicating that both A and B have well-defined velocities throughout their trajectories. But now consider trajectory C formed by the part of the trajectory A before collision, and the part of the trajectory B after collision (at the point of collision, assume trajectory C has the value of trajectory A). Trajectory C is shown in blue: My question is this: is trajectory C continuous and differentiable at the point of collision (x', t')? That is, does it have a well-defined velocity at point (x', t')? My own thoughts on this problem so far is that trajectory C is not continuous at (x', t'), because the left-hand limit of trajectory C is the point on A's green trajectory near (x', t'), while the right-hand limit of trajectory C is the point on B's red trajectory near (x', t'). But I want to understand/formalize/prove this more rigorously.


I do understand that we can't experimentally verify anything we imagine about the interior of a black hole. If we were to apply what we know about the physics of the observable universe and assume that those laws remain valid on the other side of an event horizon, then are the following assumptions at least plausible? Anything that falls into a black hole might experience perpetual free-fall, because everything closer to the singularity will experience a much stronger pull than things farther away. The observer, similarly, will experience a constant acceleration away from the event horizon, so objects that cross it after the observer does will always be moving away from them, from their point of view. Objects within the event horizon of a black hole can't interact with our observable universe, but there doesn't (to me) seem to be any reason why they can't interact with each other. So they could clump together in volumes that are small enough where the tidal forces don't rip them apart. In this way, wouldn't the inside of a black hole look like a universe where everything is constantly accelerating away from each other, but in smaller scales can still bind together through all the normal interactions that we observe on "this side"? I hope this question doesn't break the rules of stackexchange, and I'm totally ready to have all of the above bullet points torn to shreds.


I've encountered a few possible definitions of a "connected ring" and am having some confusion relating them. The first one is defined for any commutative ring: A commutative connected ring has a spectrum which is connected in the Zariski topology. But there is also the concept of a topological ring, where the ring itself (not the spectrum) is endowed with a topology. In this case, it also seems natural to consider a topological ring to be "connected" if the the ring itself is a connected topological space (irrespective of the spectrum). My concrete questions are thus: For a commutative topological ring, is there a relationship between "connectedness" in the spectrum-sense vs in the ring topology-sense? More broadly, is there any relationship between the topologies on the two spaces? They seem unrelated to me. When I read results on ring theory, I'm often confused whether topological statements refer to the ring itself or the spectrum. Take for example the following: Every compact Hausdorff ring is totally disconnected. I'm assuming here that the ring in question is a topological ring, and "compact Hausdorff"-ness is refering to the topological properties of the ring itself. But here, is "total disconnected"-ness referring to the ring topology, or to the spectrum topology that results in the definition of a "connected ring" above? Am I getting tripped up on overloaded terminology here, or is there some deeper connection that I'm missing? Thanks for the help!