darklight03/StackMIAsub huggingface dataset:
This image from NASA illustrates drag coefficients for several shapes: It is generally accepted that some variation of the teardrop/airfoil shape has the lowest drag coefficient. I was wondering what shape has the highest drag coefficient. The image suggests that it is a flat plate, and that would seem to be an intuitively correct answer, but is that correct? Is there some other shape (perhaps with a concave front or back relative to motion) that has an even higher drag coefficient?
Clouds are made out of tiny droplets of water. These droplets, to my understanding, act like tiny prisms (which is why there are rainbows after rain). From my line of thinking, if we had a room with a bunch of prisms randomly placed about and had a light enter from one side, the walls would be quite colorful. Why, then are clouds white (and then darker shades of gray as they become filled with more rain)? Edit: I understand that white is all the colors together, but if that logic applies to clouds, then why not rainbows?
Question: Which of the following affect the frequency of a tuning fork? Tine stiffness Tine length The force with which it's struck Density of the surrounding air Temperature of the surrounding air Answer Attempt: Based on the formula for the frequency, I know that tine stiffness (or density) affects it, and so does the tine length. I believe the temperature and density of air can have a slight affect as well. What about the force with which it's struck?
We're releasing a website in which the users can submit and join video game competitions. The game can be League of Legends, FIFA, Counter Strike and so forth. We're not native english speakers so we're not sure whether we should use "tournament", "championship" or simply "game" to characterize an instance of these competitions. What is the difference between these terms? Which of them would be more suitable for one single instance of an eletronic sport competition?
This is possibly a silly question but when we derive the equations of motion of a particle using the principle of least action. We must assume that there is a single minimum (for a fixed choice of boundary conditions), right? What happens if we have two minimums? How do we decide what trajectory that particle took? Is it just a case of never creating a Lagrangian with that form?
I am documenting a piece of software that will be transferred to a customer. The customer will run the software continuously. They may choose to update and improve it, but this is optional. To keep the software running smoothly, there is a minimum set of upkeep tasks that must be done periodically. Things like checking error logs, testing server uptime, making backups, and so on. For the document, I want a recognizable term to describe this set of activities. Here are words I thought of so far, which I feel are inadequate: Minimum upkeep tasks Maintenance mode Life support activities Bare-bones operation
I am working on a barn door tracker for taking astro photos. My drive train has a small periodic error that I'm trying to eliminate and I was hoping someone might be able to suggest a formula that would approximate what is shown in the attached image. The image shows three cycles of the error. It appears to me to be similar to a sine wave but with the upper half stretched out. It doesn't need to be exact, just something so when I subtract it out, I'll get close to a straight line. I hope that makes sense. Any assistance would be greatly appreciated.
I am currently completing a maths project that aims to approximate the roots of functions using MATLAB. The two root finding methods that I have used are inverse quadratic interpolation and the secant method. I have written scripts for both methods and have obtained approximations to the roots of different functions. I was wondering if it was possible to graphically illustrate the various iterations for a specific function, on the same graph, to show the method converging to the actual root value? If this is possible I would like to be able to complete it on MATLAB if not then excel? Does anyone know if this is possible or even how to go about completing it? Thank you!!
Wikipedia gives the following definition of a formal proof: A formal proof or derivation is a finite sequence of sentences (called well-formed formulas in the case of a formal language) each of which is an axiom, as assumption, or follows from the preceding sentences in the sequence by a rule of inference. Given this definition, a sequence whose final term is an axiom could qualify as being a formal proof. What would it be a proof of? The idea that an axiom can have a formal proof, seems anti-intuitive. I haven't been able to find a definition of 'formal proof' sufficiently detailed as to unequivocally answer the question posed within the title of this post.
I have heard of impulsive differential equations being used in some epidemiological models of infectious disease. I haven't heard of them before in my math education, and I was wondering how they might work. I presume there is some mechanism to introduce a step-wise/impulse discontinuity, but I'm not sure what a simple model might look light, or how it behaves. Any help would be appreciated.
In the foreword for a knitting book there's this passage: Knitting has become as ubiquitous as the humble sheep. Which is followed by a couple more sentences on how great it would be to learn how to knit etc. I've googled "the humble sheep", and haven't had any success. Is the phrase roughly equivalent to "Wool is everywhere nowadays, and wherever there's wool, there's knitting"?
I'm using the word subscription with the following meaning: subscription: an arrangement to receive something, typically a publication, regularly by paying in advance. (Definition taken from Google, I'm not sure how to link to the source) Basically, I'm looking for a word that is an arrangement to send something. Does anyone have any good suggestions for what that might be? I have thought about Producer & Publication, but they seem a little off to me. A 'Producer' can produce the something to send, but doesn't necessarily have to send them and a Publication seems like the something that is being sent.
Our company occasionally has to write letters to a third-party in response to a complaint. There are times when we only know the complainant's last name (usually with first initial). Typically, we would write something like "Mr. Jones signed up for service on..." or "Mrs. Smith contacted us on...". If we do not know the person's gender, what is the appropriate way to refer to the customer? Would we just use "complainant" or should we ensure that we use the customer's name? EX: "The complainant contacted us on..." vs. "J. Smith (the Complainant) contacted us on..."?
A Ponzi scheme is a fraudster uses money from new investors to pay old investors, so that it looks like he is doing something profitable. At some point, when all the investors want their money, he doesn't have it (because he took some of it). A key part of the definition of Ponzi scheme is fraud (the fraudster said he was making money when he wasn't). What's the word for a "Ponzi scheme", happening by accident. For example, a bunch of people may invest in a stock causing a bubble, and then the price crashes. This is like a Ponzi scheme because those who sold first got a profit at the expense of everyone else, but there wasn't any fraud since it happened by accident.
I am using Tikz externalize for the figures in a manuscript. The original files containing the Tikz/pgfplots code have been deleted (but will be regenerated in several hours when my simulations finish running). In the meantime, I would like to make a few changes to the text and give it to someone else to review. I still have the output files from the previous Tikz compilation. Is there a way to prevent Tikz from trying to rebuild these files and instead use them as is?
I'm wondering if there's a word or term for a person who looks for an opportunity to insult and berate other people. I'm sure you've all been there; you're using an online public forum, like Facebook, to voice an opinion. There's always that one person who gets completely offended, or they take things completely out of context. They then proceed to publicly scold and shame you - excessively, it seems. It makes you wonder if maybe they're just looking for something to complain about, or if they enjoy being abusive? Maybe they just get a kick out of making you look bad, and want everyone else to dislike you? "Troll" and "butthurt" seem to fit fairly well, but I was hoping to find a more traditional English equivalent.
First of all, I ain't a native speaker. And one of the most confusing sentences to me is I ain't going to this place no more. Ain't in this sentence basically means am not, so it translates to I am not going to this place no more. What exactly does no more in this sentence mean? Does it have the same meaning as any more?
I am facing an example that I am not able to understand at all. It says the the limit of a pointwise convergent sequence of positive semi-definite metrices is positive semi-definite. Basically, I do not understand how to use the pointwise convergence for a matrix, that is, I do not know a definition that is general enough to be applied to that case, and I was not able to find it anywhere. Can someone help me?
Here is the full question: Prove that every continuous function on a closed interval is Riemann integrable. Give an example of a continuous function on an open interval which is not integrable. I think he might be Riemann integrable for the second question because I'm pretty sure that every continuous function on an open interval is integrable just by definition. If that's not true, does anyone have any ideas for the answer?
I am brand new to lattices/partitions. Given that the set of all partitions of a finite set is a poset ordered by refinement, how does one prove that it is a lattice? I know you have to prove that the join and meet exist, but how does one construct them in this case? In other words, what are the join and meet of two partitions?
I have been reading about Jupiter as of late and reason I am asking is if Jupiter has strong enough gravity to pull hydrogen to itself then it should be only matter of time when it will acquire enough mass to ignite itself and become a star, same would apply to any other planet that is big enough to hold hydrogen (In other words if planet gains more matter than it looses it will become a star eventually). Or am I missing something here?
As I understand it (and admittedly it's a weak grasp), a computer processes information irreversibly (AND gates, for example), and therefore has some minimum entropy increase associated with its computations. The true entropy increase is much greater, and comes from the conversion of electrical energy to heat. How efficient is a typical desktop computer when viewed in this light? Make any assumptions you find useful about the energy use, computations per second, temperature of the room, etc.
In my mathematical writing in grad school there used to be sentences like "Whenever x is a fish, then x is an animal." (Yes, that's what my dissertation was on!) I am a native speaker of English and this seemed fine to me. My adviser (who is not a native speaker of English, though it's not entirely relevant) insisted that this was incorrect, so I stopped using it because he was pretty much the only one reading what I wrote. He suggested replacing "then" with "we must have that" (which I did). I still wonder, though...is it really incorrect?
I notice that a lot of researchers tend to have crappy-looking websites, often because they aren't willing to put in the time it takes to learn HTML, CSS, and design principles--they'd rather do research. I'm assuming that said researchers know LaTeX, as it's pretty much the standard for academic typesetting. So why not leverage that knowledge to make a kick-ass homepage? Are there any LaTeX packages or tools that are designed with the easy creation of a nice-looking website in mind? And, no, I don't mean just haphazardly turning a topology paper into a Web page.
I once asked some English people the following question: "At what time do you go to sleep?" They gave me a blank stare. You see, I tried to avoid the standard expression "At what time do you go to bed?" because it is ambiguous. I may get into my bed but may not fall asleep right away. I may be reading or emailing on my iPad or watch TV.
I'm looking for a mathematical treatment of mass action kinetics under the assumption of detailed balance. In particular, I'm interested in the proof that the free energy is a global Lyapunov function. There are many papers that prove this for the more general case of "complex balance". However, I'm not particularly interested in that generalisation, because I'm interested in applications to chemistry, which means making different generalisations that are not compatible with it. So my questions are: What is a nice, simple proof that assumes detailed balance and shows that the free energy is a global Lyapunov function? Is there a good overview paper that gives a concise mathematical treatment of the subject without making generalisations beyond what can be observed in a real (closed) chemical system?
This has been bugging me for a while, does anyone know what this word is? Maybe I imagined it. I thought it might have been "superfluous", but I don't think that is it, then I thought it might have been "hyperbole" but I do not think that is it either. Any thoughts? Here is some context. Person A: If a billion people view my web site, my server will crash. Person B: That is a ___ example. The difference between the word that I am looking for and "hyperbolic" is that a hyperbole is not meant to be taken literally and this is. Hope that helps.
Is there a term for the word that describes where a person is from or what nationality they are? For example, someone from America is an American, and someone from Finland is a Finn. Is there are term for the words American and Finn that denotes that they mean "someone from a particular place"? I could have sworn I stumbled upon such a word years ago, but I cannot for the life of me remember it.
To me "I must help her" sounds wrong. I feel that I would rarely say this. On one website they say that 'must' is more for personal obligations (e.g. I must help my mother.) and that 'have to' is for external obligations (e.g. my boss says I have to finish the report.) Is it that simple (and vague)? Or does anyone have a better explanation?
Is the sentence: "We felt we had let our coach down because we hadn't won the match" correct? I read a sentence "We felt we had let our coach down because we didn't win the match" in an English textbook. I wonder that, when we compare the happening time of the three things: A "feel" B "let our coach down" and C "did not win the match" it will be C> B> A. So is it possible to say: "We felt we had let our coach down because we hadn't won the match" also? If it is ok, too, are there any differences between the two sentences? Thank you very much in advance.
I'm interested in knowing the structure of a CNOT gate, in quantum computing. THe problem with that is, that I've read how the structure of a nuclear quantum computer works, but I still don't understand how that can be implemented to create a quantum CNOT gate. I've read the article of the original proposal of Cirac-Zoller, but it wasn't explained very good, I guess, so I want to ask, if someone has a link to some publication where it's explained better than there, possibly with more pictures rather then formulas. Thanks.
A: I can't understand why my parents keep me from buying fast food. B: Me, too. It's delicious. Does B's answer sound natural? In Korea, we usually teach that we should use 'me, neither' in a negative sentence, 'me, too' in a positive sentence. But I am not sure if this is always true. I think that 'me, too' is a valid response in this particular case, but one of my students said that 'me, too' is grammatically incorrect, so it is unnatural. Who is right?
While reading about linear algebra for math olympiads in these notes, I came across the following assertion: Remark. The set of invertible matrices form a Zariski (dense) open subset, and hence to verify a polynomial identity, it suffices to verify it on this dense subset. Could someone provide an explanation of what it means to be a "Zariski (dense) open subset"? A proof of this result is sketched in the notes, but I feel there is some deeper theory going on underneath. In case anyone is interested, the author has a similar set of notes here.
I'm in the process of learning about Matroid Theory (I'm reading Oxley's book). I came to this from combinatorics and topology. Now, I just read of connections between matroids and combinatorial optimization. Yet the only example I've seen so far is that of the greedy algorithm. So, I'm wondering if there is some astounding application of matroids to optimization. By that I mean either something that can be solved with matroids and for which no matroids-free solution is known, or something that can be solved much more easily using matroids.
The Free Dictionary defines it as "to start to accept and deal with a difficult situation," but I don't know what accept means in this expression. Does accept mean to welcome the difficult situation? That can't be right, as I've heard "come to terms with" pertain to one whose friend or family member died, and I doubt anyone would welcome that. Does accept mean tolerate, as in to allow the difficult thing to happen? That wouldn't work either, as going back to the death example, there's nothing one can do to make the dead individual stop being dead (for now, at least). So, I'd like some help understanding "come to terms with" given my trouble with the definition I've seen.
I was excited to learn that XeLaTeX finally has microtype support (I had asked about that earlier). However, after adding microtype to my document, I noticed that line breaks at hyphens now go wrong. Previously, the word foo-bar would be hyphenated as: foo- bar But with microtype enabled, I now get foo-bar and that runs over the right margin. Is this a known problem, and are there tuning parameters to fix this?
I'm working through Mumford's Red Book, and after introducing the definition of a sheaf, he says "Sheaves are almost standard nowadays, and we will not develop their properties in detail." So I guess I need another source to read about sheafs from. Does anybody know of any expository papers that cover them? I'd prefer to not have to dig deep into a separate textbook if possible.
As a physics newbie I'm trying to get a grip on basic orbital mechanics. I think I'm beginning to get grasp on how bodies interact with each other. When a body approaches another body it accelerates due to gravity. It can reach a point where its velocity is high enough to keep falling but also keep missing the object it is falling towards. What keeps it from accelerating (because of gravity) and eventually reaching escape velocity? I feel like I'm either looking at things the wrong way or I have the entire thing wrong.
I have a circle with a known center and radius. I have an arc with a known radius and two points on its edge, where one end is at the same position as the circle's center. Is there a way to find their point of intersection that's simpler than turning this into two circles and intersecting those (and somehow figuring out which of the two points of intersection to use)? In other words, the green bits of this diagram are known, and I'm trying to find the red:
I'm having trouble deciding whether the word 'name' can be used possessively. Currently I'm thinking it's correct to say: Patients' names have been altered to provide anonymity However it just doesn't look right to me. Is the above correct for a group of patients or would any of the following be better: Patients names have been altered to provide anonymity Patient names have been altered to provide anonymity
What is the rigorous justification of Wick rotation in QFT? I'm aware that it is very useful when calculating loop integrals and one can very easily justify it there. However, I haven't seen a convincing proof that it can be done at the level of path integral. How do we know for sure that Minkowski action and Euclidean action lead to the equivalent physical result? Is there an example where they differ by e.g. a contribution from a pole not taken into account while performing Wick rotation?
I have been studying the concept of transcedental numbers. Till now, I had taken it for granted that all important numbers like pi and e were transcedental. I have no reason for assuming this or for clustering them together. It's just my intuition had placed numbers like pi, e and the golden ratio together and for some reason assumed they are all transcedental. This was before I was aware of a rigorous definition of a transcedental number. I just remembered that the golden ratio is one less than it's square. So, it does satisfy an algebraic equation. Does this mean that the golden ratio is not a transcedental number?
I have a problem analysing this sentence from the point of finite/nonfinite clauses, clause elements and their functions: He does not want to destroy his parents' dream of him achieving a Cambridge degree. I am especially interested in the: dream of him achieving a Cambridge degree. I know that 'achieving a Cambridge degree' is a non-finite -ing participle clause. However what is its function? And what is the function of 'of him'? Is it a postmodification?
In a one dimensional lattice system with periodic boundary conditions, in which the last and the first site of the lattice are the same site, momentum is conserved modulo a vector of the reciprocal lattice. My question is if for a system with open boundary conditions, in which the single particle wave functions vanish in the two extremes of the chain, momentum or quasi-momentum is conserved. In principle, there is no discrete (nor continuous) translation symmetry, so momentum shouldn't be conserved. However, I wonder if momentum conservation is completely lost or if there are some remains.
When you put chopsticks (or any other object) in a glass cup of water, why do the chopsticks seem curved or bent? Is it because of the shape of the cup, the water, or the chopsticks itself? Note: I'm sorry I currently don't have an image of it. You can try this at home. Just put a pair of chopsticks in a glass of water. If you have an image, please edit this question and put an image in.
I am a first year student at varsity and I am new to Astronomy. A question came up in my tut asking about the Hubble constant and cosmological time. I couldn't answer it because I have not understood the relationship between the two. What I've heard is that H is constant for space(although I don't understand what that implies), and is not for time. What does this all mean?! Please help...and please keep things simple.
Consider the quote from "What is a Grantor Trust" article. This trust is revocable, which simply means it can be altered, modified, and otherwise changed or even terminated during the life of the grantor, provided that the grantor has full mental capacity. As far as I could figure out from other forums words "alter" and "modified" mean "to change slightly", and "change" is more generic word and may also mean "replace" or "exchange for something else". The text in bold sounds to me like "it can be slightly changed, slightly changed, and otherwise changed". Are there some differences in meaning between "alter" and "modify" in this context or in general? Are they generally interchangeable?