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My question is on the nature of oscillating electric field. From Maxwells equation, we know that the solution of the electric and magnetic field for an empty space are always oscillating fields. I learned that oscillating fields are connected to oscillating charges. However, what about the case when the the charge is not oscillating but rather, lets say, just linearly accelerating over a given distance. The field gets disturbed once the particle accelerate suddenly but what I don't understand is why this would still cause an oscillating field rather than just a locally distribution of the field. Hope my question is clear. | 0 |
I would like to know whether bounded linear integral operators (defined on a separable Hilbert space of functions) always have a countable point-spectrum. Or if not, what would be a practical counterexample. The following situations for instance already lead to a countable point spectrum: self-adjoint (or symmetrizable) operator kernel integral operator with bounded kernel But what about bounded integral operators in general? I couldn't find any helpful theorem. | 0 |
I'm trying to ad some probabilities on my model and I'm wondering which conditions are needed on my initial space. I'm starting with a metric space X and consider the set of operators from X to itself equipped with the topology of compact convergence. Let's consider the Borel sigma algebra of this space. Does there always exists a Probability on this measurable space ? Do I need some stronger assumptions on X ? EDIT : I forgot to specify that I'm asking about the existence of a probability with a "large support", equal to the space or infinite Thanks ! | 0 |
I'm trying to find models that allow me to calculate dropped objects, specifically, a model where I can consider lateral displacement due to wind force and vary the weight and resistance force of the object. This is crucial because I'm trying to calculate with utmost precision the point of impact of a tool falling from a height at a construction site, to determine the safety zone that must be established below to prevent injury to anyone. I appreciate any information in advance. | 0 |
It is my understanding that sets are said to contain their elements but also a set is said to contain its subsets. However, I feel like this might lead to a confusion since while a set contains its subsets, its subsets are not necessarily elements of it. It seems to me the word "contain" must be restricted to only one of these meanings and there must be another word for the other. Am I missing something here or is this supposed to be understood from the given context? | 0 |
As far as I understand a material is a better thermal conductor if its thermal diffusivity is higher. The thermal diffusivity is inversely proportional to density, thus denser materials have higher thermal diffusivity all else being equal. Intuitively I would have expected the opposite to be true! Atoms close together interact more often with each other, transporting thermal energy more easily. In my mind that would explain why gases (and 'zero density' vacuum) are good insulators. Why exactly low density improve thermal diffusivity? | 0 |
I believe anyone who has driven a car without power steering has noticed this effect. I am not able to find a justifiable argument online. My thought process suggested it must have to do something with the static friction in the case of a moving car which provides it a centripetal acceleration, but I am not sure. A reasonable and complete argument will be much appreciated. | 0 |
It is easily shown that in proving compactness, we can assume the arbitrary open cover is given by a basic open cover. However, the same proof does not work when proving countable compactness. The reason is that not every open set can be written as a countable union of basic open sets. So my question is: in proving countable compactness, is there a counterexample showing that we cannot assume the cover is by basic elements? Note that such a space cannot be second countable. The trivial example of a discrete uncountable space is not a counterexample. | 0 |
In A_Treatise_of_Human_Nature, of David Hume, it is written: For if truth be at all within the reach of human capacity, it is certain it must lie very deep and abstruse: and to hope we shall arrive at it without pains, while the greatest geniuses have failed with the utmost pains, must certainly be esteemed sufficiently vain and presumptuous. I gathered that the usage seems to be to lie deep instead of to lie deeply. Why does an adjective follow the verb lie instead of an adverb? Is lie here a linking verb? Would the phrase It is certain it must lie very deeply and abstrusely. be incorrect? | 0 |
There is a book that is called embeddings in manifolds that studies topological embeddings and how they relate to each other (by homeomorphisms). I was wondering if there is a study of isometrically embedded polytopes in manifolds. "Isometric" here would probably mean conservation of the metric (as in metric spaces) rather than the Riemannian structure. So I would like to ask if there is anything I can find on the topic, if there is such topic, preferably a book but papers will do as well? | 0 |
I understand that the steady-state Kalman filter is more computationally efficient because the noise in a measurement equation and the shock in a state equation have a constant variance over the time period. However, what model should I use if I want to study the effect of a noise shock, which refers to a large shock that was not imaginable? Should I use a time-varying Kalman filter that allows for the variance of noise to vary? I am faced with this question because I cannot exactly tell the differences between these models and their respective advantages and disadvantages. Please help me out. | 0 |
I need to know the grammar and syntactical explanation of a phrase in the following sentence: The protest was reportedly linked to members of the group objecting to the replacement of the group leader. Is this phrase "members of the group objecting to the replacement of the group leader" an absolute phrase? If so, can absolute phrases act as the objects (noun clauses) of verbs? | 0 |
The back side of a coin is called reverse, the left or back side of a bound manuscript is the verso, but what is the back of a piece of paper such as a letter (not the envelope) called? Dictionaries give a wide selection of options (rear, back, reverse, backside, flipside, back page, etc.), and I don't understand which of these a native speaker would most likely use here. I would like to direct the reader of a formal letter (which in this case is a legal document) to further information on its back, e.g. "bla bla (see the back of this letter)". | 0 |
I found this https://en.wikipedia.org/wiki/Harmonic_oscillator in my search results when I search for "electrical oscillator Hamiltonian" and some other things too. But none of them answer my question about the form of the kinetic and potential energies of an electrical oscillator. Searching for the kinetic energy and potential energy does not show up fruitful either such as here. I am specifically looking for an electrical oscillator Hamiltonian. Any help would be appreciated. | 0 |
We are learning the rational root theorem right now. It is pretty clear how to prove a number is irrational when we know how to construct a polynomial that only includes integer and has the irrational number as a root (rational root theorem). However, if it comes to sum of two number with different power, it is pretty hard to construct the polynomial. Is there a general way to construct polynomial? Or is there any alternative ways to prove this question? | 0 |
If we have a smooth and frictionless pulley with two different masses attached at the ends of the rope (meaning they will accelerate) and the pulley is attached to the roof by a string, why cant we consider everything as one closed system and calculate the wieght of the that system to find the tension on the string attaching the pulley to the roof. After thinking for some time I feel that somehow allowing the masses to accelerate in one direction is relieving some of the force on the pulley. But why? Why can't we consider it a single system and find its wieght? | 0 |
I think it is computing the fine-grained entropy. However, I am confused by the case that when there is a black hole in the bulk. The Ryu-Takayanagi surface may include the horizon of the black hole in this case. However, the Bekenstein-Hawking entropy is a coarsed-grain entropy. I have also heard that the RT formula is computing the coarse-grained entropy of the complementary region. What does this mean? | 0 |
I am working on a model of a Fe square planar complex with nitrogen and oxygen given below is a monomer of that polymer. While constructing the hamiltonian matrix of this monomer I'm confused as to if I should take the orbitals of Nitrogen and Oxygen as normal atomic orbitals or hybridised orbitals? I tried to search up about it but couldn't find any method that used hybridized orbitals | 0 |
While solving this problem, we arrived at the solution in a form of discontinuous function of electric field. Intuitively it doesn't seem right. What is a physics explanation behind this discontinuity? Or is the mathematical approach wrong? Or is it just so idealised problem that it doesn't exist in reality anyway, so discontinuity doesn't have any physics meaning? Tried solution (electric field as sum of electric fields of all thin rings): | 0 |
I am a mathematician and a while ago I started studying quantum physics. I know the concept of superposition mathematically, but my question is regarding a famous experiment that Aaron O'Connell performed. Link to the TED talk that describes the experiment: https://youtu.be/dvYYYlgVAao He says in this video, "The small piece of metal was vibrating and not vibrating at the same time." I did not understand this phrase because it seems illogical. Can this be explained in the experiment and is his statement correct or is it just to stir up the audience? | 0 |
I a m a high school student who has spent a lot of time learning about limits but still do not understand how they work completely. What I have understood is that sometimes a function does not have a y-value/s for one/(or more?) x-value/s however, since we know the y-values of the x-values close to the x-value with an undefined y-value we can approximate where the y-value for that x-value will be. To express this we use a concept called limits. My question is, can we use limits for functions where there is a y-value for every X-value? If yes,why would we do that? To show the behaviour of the points of a function as they get closer to a certain point? Thank you in advance! | 0 |
(I know this is going to sound odd just please consider it) What if you were to throw an indestructible ring straight into a black hole with a hole larger than it's singularity? Would its trajectory be straight through the black hole missing the singularity? If this is the case then wouldn't it reach escape velocity and as result break the speed of light? Think of it like a ball rolling down a hill and being able to speed up enough to roll back up a hill of the same height. I understand that a black hole achieves it's event horizon through distortion of space time so what I am truly pondering is if it would have a straight and un-impeded trajectory through the black hole. | 0 |
I found this problem on Facebook from a Mathematics group. Apparently it had appeared as one of the problems on a college entrance exam. The person who shared it on Facebook did not disclose the correct answer. I'm going to post my own approach below, please let me know if my answer is correct or if there are any other methods possible. (I even encourage solutions that may typically go beyond pre-college level mathematics.) | 0 |
Every well-ordered set is linearly ordered. However, is there a notion of well-orders that generalizes to partial orders? Maybe, the generalized definition will be that every non-empty subset has a minimal element, not necessarily a least element. I would be very interested to hear about such a definition, and more importantly, I would like to know about research on this topic about these "generalized" well-orders. | 0 |
I use VS code with the Latex workshop on Mac and it works perfectly fine when writing a paper. But I don't understand "pdflatex", "mactex", "texlive" or something other people are saying What are the essential components to compile a paper using Mac? How can I check what is working behind my VS code? (I don't remember what I installed so far to make my environment possible ) | 0 |
I was reading in a patent that a rotating spherical body in space will experience a curvilinear translation, due to the conservation of angular momentum. This confuses me, as per my understanding if there is no friction, or any other force applied, conservation of angular momentum will keep the same rotating speed but I do not see why it will make it move/translate from its location. On the other hand, I have seen a video of a spinning object in the ISS changing direction alternatively, and I also do not know how it happens, in that case there is no translation that can be observed, but there is still friction with the air. Anyone can give some insights? Thanks! | 0 |
I am just wondering how do we transfer IMU readings to Body frame? Especially, linear speed and acceleration. In following diagram, the IMU is mounted on one of the surfaces of the body (you can imaging it to be a bot, vehicle, drone, or etc.). The center of the vehicle is at Body (green) point in this diagram, and it is on a different surface of the body. Both IMU and Body point are on a rigid body which moving in an inertial frame. Any hint is highly appreciated. I'd really appreciate if there are some references. Thanks! | 0 |
I am wondering about the correct verb form to use here: This article limits itself to consider... or This article limits itself to considering... For this example both sound dubious to me (possibly because of the presence of 'to'), and those I have asked are also unsure, including a native English speaker. And what about the passive counterpart: This article is limited to consider... This article is limited to considering... | 0 |
Earlier I was using texstudio with MikTex. In MikTex, I am facing some issue with its updates. So, I downloaded MacTex. How to configure texstudio with MacTex? When I am running texstudio, it is taking MikTex compiler. The error is shown below. Sorry, but /usr/local/bin/pdflatex did not succeed. The log file hopefully contains the information to get MiKTeX going again: /Users/bp/Library/Application Support/MiKTeX/texmfs/data/miktex/log/pdflatex.log pdflatex: major issue: So far, you have not checked for MiKTeX updates. | 0 |
I am confused by the definitions of a gauge transformation, a coordinate transformation and a diffeomorphism. In particular, should observables in GR be fundamentally invariant under gauge transformations, coordinate transformations or diffeomorphisms? For example, in these notes by Bertschinger, observables should be gauge invariant, and he defines a gauge transformation as an infinitesimal diffeomorphism. This appears standard and in line with e.g. Sean Carroll's GR textbook. On the other hand, there is this paper by Yoo and Durrer, which claims that cosmological observables are invariant under diffeomorphisms but not gauge transformations in general. Their definition of a gauge transformation appears to refer to simply "an equivalent" coordinate transformation - the sort which Carroll disagrees with being strictly correct in his textbook. | 0 |
Is it correct to say "None can stop me?" I feel like "No one can stop me" is the one I've seen used most often, but I'm not sure if "none" works too? Does there have to be a specific context where there are several people: e.g. "There are many who will try, but none can stop me." And in other contexts (without specifically mentioning other people) "none" doesn't work? | 0 |
I'm having trouble reading documentation from packages. It seems like there's something wrong with the way I'm reading them. How should I read them, in order to learn how to use the packages correctly and efficiently? Also is there a place where you can learn typography related topics in LaTeX like glue and boxes? I don't find it talk all that much, and if they do they don't teach me why that's necessary. I haven't learn the details of typography other than fiddling with MS Word. And I would like to learn how to make is so that the fonts and font size aren't too long for the average characters per line. | 0 |
On the average Semi-trailer truck, assuming an average load, can the engine overcome the brakes and continue spinning the wheels despite the operator applying the brakes fully? This would be assuming the brakes are in good operating condition, and are not overheated or failing in some way. Additionally, would this also be the case if the tractor unit had no trailer on it, and no weight? How about fully loaded? | 0 |
I am having a conceptual difficulty understanding the following issue regarding space-time: it is clear to me why a full description of coordinates requires three spatial dimensions plus time. However, Linear Algebra also teaches that dimensions needs to be independent from one other, such that my movement along one dimension has no bearing on my movement along another dimension. This does not seem to hold in space-time, given the effects of time dilation and space contraction, which is essentially a rescaling transformation of one dimension based on the object's velocity along another. This seems to preclude such independence between said dimensions. Can somebody clear up my confusion? | 0 |
In the case of big freeze, space expansion will be accelerating and there appears to be a lot of different phenomena occurring. However, in the case of big rip, the expansion is super-accelerating so that light speed will be reached, ripping apart every structure. How come this speed is not reached in the case of big freeze. If the speed of expansion is accelerating, it should reach light speed at some moment. How does the evolution of scale factor in this case look like? | 0 |
So far I have not needed to insert jpg images in my LaTex files, but now I want to write a text that will include some pictures. I would like a format where the picture doesn't take the full width of the page but be rather set to the right or the left and the remaining space on its side filled with text. I have tried to use the figure environment from the graphicx package together with a minipage environment, but failed. What would be the best way to proceed? Is it safe (or even possible) to change from a one column format to a two columns format in the middle of a page? | 0 |
It's on the tip of my tongue. The great thing about this word is that there's a connotation that a person it describes is not just smart or curious, but that they find a childlike joy in learning. This word is paired with the word "intellectually", as in "intellectually curious." But when it's on its own, it's more likely to be describing someone who's cheeky or sassy, particularly a child. But in that usage, there's the connotation that their cheekiness or sassiness belies gifted intelligence. I am pretty sure it starts with a p, or even maybe 'pro,' but I could be wrong about that. | 0 |
In indirect speech some modal verbs usually change. can -> could He said "I can ride a bike" = He said that he could ride a bike may -> might/could He asked "May I use the bathroom?" = He asked whether he could use the bathroom But what about dare? It can be a modal verb. "No one dare go there" he whispered = He whispered ... | 0 |
I'm from South America and I've been fluent (at least in my opinion) in English for several years as of now. With this in mind it has really called my attention lately that I've heard Afro-American people say, for example, "I don't like no cats" instead of "I don't like cats". With double negation. And the other one is, for example, "Look at them kids" instead of "Look at the kids". With them instead of the. It is not really confusing tbh but I'm just curious about why this happens? | 0 |
Would it be feasible to extend the range of an EV using a generator? I would guess that F=ma and perhaps a myriad of other factors would make a generator placed on an EV not work very well. I think of things like a wind generator to capture the wind power but the drag would slow the car down thus canceling the added energy. Or how about a generator in the rear wheels of the car to add back some of the loss? I could imagine something like that working in a downhill scenario but i can't see it adding much if any in the whole driving scheme. Seems Elon would have figured this out by now if any such thing would be feasible. What you guys think? | 0 |
This question is not similar to what I have read so far in this site. I am just trying to understand what electricity actually is. I have come to know that when charges move or vibrate in a wire by the supplied voltage, the electrons drift velocity is very slow. And the bulb glows instantly because energy travels through EM field, which is perpendicular to electric and magnetic field. Now, comes the question, suppose if I create a circuit, and connect it to the battery. So, the bulb will glow, but what if I put another unconnected wire near the circuit connected with another bulb. Will the bulb glow? Because electricity travels through EM field. Shouldn't the bulb glow? Which actually doesn't happen. I am just confused. | 0 |
Let's assume a galaxy has super massive black hole in it's center. We can't see what's inside the black hole because light cannot escape from it. In simple terms, black hole is a hole in the space and also assume that this black hole goes down all the way somewhere, like a straw/pipe that we cannot see. So now imagine a a spaceship is traveling exactly beneath the supermassive blackhole (but far away from event horizon where the blackhole can't pull it inside). And now what happens if the spaceship hits the blackhole straw/pipe? Just trying to understand is there any science that we can use to see where this blackhole straw/pipe goes to from outside. Or what happens if a spaceship or a planet hits this pipe? | 0 |
The s-procedure or s-lemma tries to solve a system of quadratic inequalities via a linear matrix inequality (LMI) relaxation. There are many different enunciations and if you are not sure what i mean you can check here. I have seen it be used in papers where the inequalities are not quadratic, for example here, but I cannot find a form of the theorem that seems to apply. Can anyone help me? Thanks in advance. | 0 |
I remember hearing at some point that pertubation QFT using Feynman diagrams can be thought of as certain limits of lattice QFT. Is there a precise statement of this fact? Or is it just a heuristic with no mathematical formulation/justification? Alternatively, is there a way to do calculation on lattices, that gives the same result as calculating Feynman diagrams, taking into account things like Pauli Villars/dimensional regularizations and renormalizations? | 0 |
I have read so many posts about the implication, but I am still confused. The statement "if A, then B" is always true when A is false. But I think that when A is false, nothing can be concluded. Moreover, I do not understand the example, "If today is Saturday, then tomorrow is Monday." As today is Wednesday, both sentences are false so the implication should be true, but it seems in daily life that this implication is false. | 0 |
In the Vlasov variant of Boltzmann equation, the Coulomb pair forces are included via the force term that appears as the prefactor of the derivative of the density with respect to velocity. In that case, one is effectively calculating a mean force or a "force field" by averaging over all the pair forces. The average is obtained by an integral over the pair potential weighted with the density. Since this Vlasov approach allows to have good analytical insight into systems mainly governed by Coulomb forces (i.e Landau damping and other), is it possible to apply the same approach for Lennard Jones pair forces ? I could not find references and I do not understand why this is the case. | 0 |
I'm junior student in physics major, and i didn't study QFT or other graduate course yet, just undergraduated QM. Recently I take brief explanation class about SUSY, and in the class I heard that simple harmonic oscillation (SHO) is important because it is unique potential which is invariant under some gauge transform therefore it doesn't change some kinds of scattering properties (reflection coefficient, etc). Is SHO only example which is invariant under the gauge transform in SUSY QM? In the description, what kind of gauge transform is meant? How does the gauge transform relate to SUSY? | 0 |
I have a bit confusion of understanding. The central limit theorem in statistics states that, given a sufficiently large sample size, the sampling distribution of the mean for a variable will approximate a normal distribution. But the definition of sampling distribution is the probability distribution of a statistic that is obtained from many random samples of a specific population. I don't get it and see a contradiction of how getting a sample distribution from one large sample as CLT states while sampling distribution definition says it needs more than one sample? | 0 |
I am trying to understand the hall effects and have a few problems with them. So let's consider the classical Hall effect. We know that we consider a sample, where the electrons flow, we apply the perpendicular magnetic field, and the electron's motion is curved so they reach the sample's edge. There appears a "new" electric field. On the other hand, the quantum Hall effect sometimes showed that electrons move in a closed circular orbit, but not in the edge where they can go through "skipping orbits". So my question is, why in classical hall effect the electrons teachers the sample's edge and don't just move in a circle? What is more, do they move also along the edge like in the quantum hall effect? | 0 |
I want to say that a particular painting never gets old because you notice something new each time you look at it. What is a noun to describe this quality? An example sentence would be: "Due to the xxxx of the painting, you see something new each time you look at it." An example to the opposite of this word would be a pop song that you get bored of after a few listens. Compound words are fine as long as they are nouns. The answers to this question come close to what I'm looking for but don't fit exactly since in my situation it's not the object that changes but it's so complex that your perception of it is different each time. | 0 |
Leaving school seems like such a huge event in our lives. There's this single summer where you have more freedom than you've ever had before with a group of people you've grown up with before you all go off in different directions in life: work, uni, travel, whatever. It might be the last chance to spend time with these people before you ever see them again, and so people want to make the most of this time, moreso than other summer breaks. It therefore seems strange to me that I've never heard that summer be given a special name, even in slang. Whether it's a formal term, colloquialism, slang, or TikTok hashtag, has anyone ever heard a name for this liminal period straight after compulsory education? | 0 |
In my understanding, light works as follows: every point in space where there is light, this light works as a point source. When we progress in time, the light spreads out from there in all directions (spherically). The new locations where the light is now, act as new point sources. From this it follows that the light from a laser beam would go in all directions, not just in the direction of a laser. However, we see in practice that (most of) the light only goes in the direction of the laser. How is this possible? | 0 |
I'm studying about method of undetermined coefficient. But i can't make sure when method of undetermined coefficient can be used. I know that the differential equation need to be non-homogeneous and the non-homogeneous terms need to speical form such as polynomials, trigonometric functions, or exponential functions. what I'm wandering is following: To use the method of undetermined coefficient, the coefficient need to be constant? and the differential equation need to be linear?? | 0 |
According to the dictionary, the "e" is optional when a word ends in "-dg(e)ment". Dictionary examples: oxfordlearnersdictionaries.com: "acknowledgement" (also "acknowledgment") oxfordlearnersdictionaries.com: "judgement" (also "judgment", especially in North American English) oxfordlearnersdictionaries.com: "abridgement" (also "abridgment") ...And some other similar examples from the internet: ledg(e)ment, lodg(e)ment, grudg(e)ment. Of these, only judgment is explicitly said to be found "especially in North American English"; regional distinctions don't seem to play a role in any of the other options. Is this statement verifiable? What is the evidence, and how widespread is the variation? Is there a historical reason for judgment being unique in this sense? (If it even is unique...) | 0 |
Given two points and a line in the plane, is it possible to construct a circle tangent to the line which passes through the two points using ruler and compass? For those who don't know, these are the rules of ruler and compass constructions: you start with a set of initial objects (points, lines, etc.), at every step you can do one of the following: Construct a line or segment between two points in the set Construct a circle with a segment within the set being its radius Intersect two curves within the set Each of these moves add the outcoming curve/point to the set. | 0 |
If I understand correctly, the intensity of light is proportional to the number of photons hitting a certain area. If we then look at a single photon when described as a transverse wave, is its own energy equal to the square of the amplitude of that photon's wave? If we have a high energy photon this would mean the amplitude would be large, and the converse for a low energy wave. | 0 |
For example a car with a known speed and mass crashes with a completely unyielding wall. The car has a crumple zone, (and you know the modulus of the crumple zone) so it doesn't stop immediately, but how can you calculate the time it takes for it to stop? I've been reading a relevant article (Analytical approach for vehicle body structures behavior under crash at aspects of overloading and crumple zone length) but their equations are beyond me. First question, had a hard time finding any help with this. Thanks! The journal article in question: Analytical Approach for Vehicle Body Structures Behaviour Under Crash at Aspects of Overloading and Crumple Zone Length | 0 |
I am a Physics Major. I have done an undergraduate level course of differential geometry. I want to get into symplectic and Riemannian geometry, but I would like to start over from differential one again. I found this book that seems to cover what I want, but I am not sure if it is a good book or not. Can someone recommend a book or other sources (or even roadmap of multiple books) that start from differential geometry and teaches till (or gives proper introduction to) Riemannian and symplectic geometry (physics perspective is preferred but not necessary). | 0 |
Consider that I have a piece of paper, and I do a drawing on such paper. Now, consider the set of all possible "transformations" I can apply to this piece of paper that do not tear it. For example, I can rotate it, I can do an origami, I can make it into a cylinder... Is there a name for the set of all of such transformations? Could I say that all these transformations are within the conformal transformations, i.e. since conformal transformations also have scaling, could I say that the set of such transformations that do not tear the paper are within the set of conformal transformations? | 0 |
I've known that the distance between a compact set and a closed set is zero if and only if they are not disjoint, and I can also find counterexamples in which two disjoint closed set has zero distance. But how about a closed set and a bounded closed set? Does there exist a closed set and a bounded closed set with zero distance between them, and they are disjoint? The counterexample should not be found in Euclidean spaces though. | 0 |
I use xsim to create exams and it works very well. I kove the way it handles exercises and solutions. Now I'm starting to create a script and I was wondering if there is a way to hide the numbering in exercises so I can just write an unnumbered exercise and hide the solution for the students but leave a blank space for them to write in. | 0 |
I have an experiment where I have to find the damping coefficient of a compound pendulum situated in a clock. It swings at a very low amplitude, so I think I can make a small angle approximation. Because if I assume it has SHM, I can simply use logarithmic decrement to find the coefficient, which would make my work a lot easier. I cannot find much literature on whether a compound pendulum can even display SHM. | 0 |
This is a naive question. I am studying the surface-adsorbate systems using DFT calculations implemented in VASP. By setting LVHAR = True, I obtain LOCPOT which contains information about the ionic and electrostatic potential. I would like to clarify whether this information is actually the electrostatic potential or the electrostatic potential energy. My source of confusion is that VaspWiki states that the electrostatic potential is written in terms of eV, which indicates it should be an energetic quantity. | 0 |
The first pair of these sentences with perfect participles, shows a reason while the second shows a time, and this is how the teacher taught me their meaning, so I want to know why one is reason and the other is time. How can I know that one describes reason and the other time? Please convince me. He has failed four times already, he doesn't want to appear in the examination again. (Reason) Having failed four times, he doesn't want to appear in the examination again. (Reason) He has a lot of money in business, he doesn't want to risk his money any more. (Time) Having lost a lot of money in business, he doesn't want to risk his money any more. (Time) | 0 |
I am a person who gets bored all the time, so I found that counting something in my head helps occupy my time. I started counting in binary, but after a while this started getting old as I was doing it in the back of my mind, so I got bored again. So, my question is, can you count up prime numbers in your head using a "mind-friendly" formula, or is there something different you can count that keeps your mind busy? | 0 |
In the adjoining table, a dot indicates the combination of chemicals that cannot be placed in the same location as the other because of safety issues. If a company is dealing with the chemicals a,b,c,d,e,f,g,h,i,j listed in the table, what is the minimum number of storage locations needed by the company? My idea of the solution is something like this: I start with 'a'. I can collocate it with c,d,f,g,h,i, but not with b,e,j. But then, I note that d and f cannot be collocated. How/where do I go from here? | 0 |
I'm learning the grammar of relative pronouns; I thought all relative pronouns should be at the start of a clause, and then I learned that pronouns can be put after a preposition, as in "The bed on which I was lying...", but again, I came across some other examples that showed that we can put more words before the relative pronoun, as in "The bed, the owner of which we had seen previously, ...", or "The bed, lying on which was a small cat, ..." Does anyone know what are the rules? Can we put the relative pronoun anywhere in a clause? What about these sentences: "The bed, we had seen the owner of which previously, ..."?, are they grammatically correct? | 0 |
A ball is bouncing elastically after its collision from ground so can we call it SHM as it is oscillating and also it is periodic and it seems similar to other cases of SHM? If yes then where is it's mean position? But the thing is in SHM force always opposes direction of motion but here it is always in the same direction that is downward force(due to g). Also in SHM force is zero at the mean position but here force is never zero. There can be some flaws in my understanding of SHM as I am new to this. But all the answers are welcome!! | 0 |
I have generators for my group in GAP. Additionally, I possess a specific unitary element and wish to determine whether this unitary element arises from the Lie algebra of my group's generators. Initially, I considered a brute-force approach, intending to compute the matrix exponential of a particular generator of the group. However, I couldn't find any matrix exponential function in GAP (e.g., expm, ExpMat, MatExp, etc.). Now, I have two questions: How can I compute the matrix exponential in GAP? Is there a systematic method to compute the Lie algebra of the group generators, allowing me to identify my specific unitary element, and subsequently terminate the computation in GAP? | 0 |
I am doing a review for an article where I need to write some equations myself and want/have to stay anonymous. So far I plan to just LaTeX my notes, compile them with latexmk -view=pdf and send them in. My fear is that latexmk/pdflatex adds metadata that will break the anonymity of the review process. I checked the result with pdfinfo, and could not find info that would identify me in this case. But in general I would like to not only rely on some defaults of pdflatex, but to know if there is a cheap way (preferably via CLI options) to guarantee, that there is no identifying metadata. | 0 |
I'm making a roster in a spreadsheet of all the current employees, volunteers, sports coaches, and other workers at a school. What is the best way to label the column showing if someone is Full-time, Part-time, Volunteer, or On-call (like substitute teachers)? What word represents this? I already have a Status field denoting Current vs. Former. Should I just merge this unnamed field so that Current becomes more precise as Full-time/Part-time and then Former? It's in the same logical realm, I think. | 0 |
I am looking for an algorithm that could determine adjacent extreme rays of a polyhedral cone (extreme rays that share a face), given the set of inequalities defining the cone and an extreme ray for which the adjacent rays are to be determined. I was hoping there exist a python library that might already have coded up, but I could only find pycddlib, which seems to need to determine all extreme rays first. This seems inefficient to me: I was hoping there would be a method that doesn't neccesitate computing all extreme rays first. Thank you for help! | 0 |
I want a certain path that I generate to remain hidden (so I use the path command without actually drawing it), so that I can use that path to compute other points of interest such as intersections, but I don't want that hidden path to affect the overall scaling of my shown figure. Is there a way to generate such a path that does not affect the overall figure scaling? | 0 |
I am writing an article about data mapping, and discussing the various types of challenges in mapping data elements from one system to another. One of these challenges is assuming that a data element called X in one system is the same as a data element named X in a different system, simply because they are named the same. I am looking for a classification for words that have multiple, disparate meanings. My mind keeps jumping to polynomial, but I need that type of word that would relate to the meaning of words. Poly-meaning-al? | 0 |
I am trying to understand the following to defintions of being "intrinsic". They are from Differential Geometry of Curves and Surfaces by Tapp. Question: In what way are these defintions consistent? To call quantity intrinsic if it can be expressed completely in terms of the first fundamental form makes sense. To me it seems that requiering invariance w.r.t. isometries captures different properties that I would expect from intrinisc properties. For example that deforming a surfaces should not alter the length of a curve on that surfaces. It seems to me that there are two types of intrinisc properties and that the "intrinisic geometry" consists out of these. Many thanks in advance for any hints or explanations! | 0 |
If we consider a charge in space then we can draw infinite number of spheres (taking the distance between the spheres equal) around the charge and these spheres act as equipotential surfaces. Now, As the distance of all points on the sphere are same from the charge then why does equipotential surface gets farther apart when electric field decreases??i mean my questions is what is the problem with taking the distance between equipotential surface equal?? | 0 |
When someone tends to hesitate to acknowledge a problem and avoid involving trouble even if needed, is it ok to say in a negative nuance that He/She always has a "don't rock the boat" attitude. I found the below definition at Collins Dictionary and considering that, it seems that not rocking the boat doesn't necessarily have a negative meaning: If you say that someone is rocking the boat, you mean that they are upsetting a calm situation and causing trouble. (www.collinsdictionary.com I'd like to describe a person who usually avoids troubles and never speaks up regarding existing issues such as social issues with a negative implication. I'd appreciate it if you tell me appropriate phrases to describe such a person. | 0 |
I'm struggling to explain it, but some examples are (mention does not imply endorsement!): Sir Keir Starmer -> Sir Kid Starver (criticism of his stance on child benefits) Benedict Cumberbatch -> Butterscotch Candybatch (surreal humour) Financial Conduct Authority -> Fundamentally Complicit Authority (critical of regulatory capture) Saddam Hussein -> Sadman Insane (general derision) These are nicknames, i suppose, but they are a specific kind of nickname. | 0 |
I was attending lectures om holography where the lecturer kept on mentioning that a QFT lives on a Cauchy slice. What does that mean? Is it such that each point of the slice is associated to a unique vector in the Hilbert space? Can this be generalized to QM? Does that mean that the harmonic oscillator lives on an integer lattice? Is this geometric correspondence the motivation behind the operator state correspondence? | 0 |
I am just a high school student. I had already heard that we can't determine the exact location of big bang. So now i have a question can't we approximate it? Like say divide the observable universe in many grids and you take the Average age of each grid and do this for all the grids. I assume intuitively that on average the parts of the observable universe which were formed earlier would be closer to the point of origin of the big bang right? I know that there are other effects to consider such as expansion of space but still it is not possible so my question is why? | 0 |
Let (B, S) a multi period binomial model that is arbitrage free. Prove that the unique time for an American call is the maturity T. I would like to prove that the unique optimal exercise time for an American call option is the maturity time T. My idea is to prove this result by contradiction. I want to find an exercise time t<T, such that there exists an arbitrage opportunity, so that the value of the portfolio at time t is greater than zero, starting with an initial value equal to zero. Is this a good idea, and how can I find such strategy explicitely? | 0 |
Let's say a small magnet is attached with its South pole on to the north pole of a bigger magnet vertically.There is no friction between the magnets so this means the normal force increased due to the attraction doesn't have any effect on its tendency to fall.My question is that : Does the small magnet slide down OR Do the magnetic field lines have such a property to pull the magnet up. Also, what changes are seen if the small magnet is attached vertically to a iron bar (frictionless again). | 0 |
I'm attempting to self-study real analysis and was looking at the popular textbook recommendations. So far, I've seen Abbott and Cummings for beginners. With Rudin, Stein, Bartle, and Zorich for more advanced books. My question is : What book is the sort of "Bible of Real Analysis" or reference book, where if one knows the book from cover to cover he would have a colossal grasp on the subject. To clarify my question, I mean a textbook that would cover the whole surface of analysis after learning it from a more elementary book such as Abbott or Zorich. | 0 |
I understand that if there are different capacitors of different capacitance then they can store same charge at different voltage differences only. But I wanted to understand that why the above happens when the capacitors are arranged in series...I want to know the mechanism behind that if we arrange different capacitors in series then they store same charge at different potential differences.....why they store same charge only that is flowing in the whole circuit due to net potential difference of the circuit....why they don't store different charges whose sum is equal to the net charge flowing in the circuit? | 0 |
I am currently studying the method of characteristics. So far I understand what I read in literature. The problem is that I didn't find a good explanation for imposing boundary conditions anywhere. Also, in the textbook problems, only the initial conditions are given. Please recommend me some literature where I can study how to impose boundary conditions on the solutions obtained using this method. A hyperlink to the literature would be of great help. | 0 |
Are there any public stats that demonstrate how much literature is produced in LaTeX as opposed to Microsoft Word, Adobe InDesign, etc? When I search "latex market share" every single result talks about rubber/pillow/mattress companies and not the typesetter. From what I have heard LaTeX is heavily used in Math & Science theses, and I would like to find specific numbers to back that claim. Does LaTeX stand a chance against other software outside the Natural Sciences, its stronghold? | 0 |
I have read a recently published paper on arXiv where the scientists claim to have developed a superconductor material working at room temperature and pressure. While it is clear that the results - if proven true - are preliminary, and that a lot of refinement would be necessary anyway, I am wondering what technological advances can we expect from such a discovery? Or, what technologies are currently impractical, impossible or unexplored due to the impracticality of currently industrially available superconductors? | 0 |
Our teacher told us that objects store potential energy in them according the position of the object above the ground because of gravitational force. Like we are holding a box up and it stores potential energy, and if we drop it, its potential energy gets converted to kinetic energy. My doubt is, If, we send a rocket outside the Earth, then after some point, the influence of Earth's gravitational field nearly comes to an end, Then where does the potential energy of the rocket go if we stop providing it velocity (Like dropping the box)? | 0 |
I'm studying a math book. There is a definition as seen below. A category is a class C of objects (denoted a,b,c ...) together with (i) a class of disjoint sets, denoted hom(a,b), one for each pair of objects in C... (ii) ... I want to ask which one of the following meanings should be deduced from this statement regarding the grammer rules; hom(a,b) is one of the sets of a class. hom(a,b) is a class of disjoint sets. The whole thing may confuse you so please just consider the part saying: " a class of disjoint sets, denoted hom(a,b), one for each pair of objects in C..." | 0 |
Please see here to see question & my solution Here are question & solutions I tried. How should one approach problems where both s-shifting and t-shifting are required? Is there a specific method or sequence that is recommended? I have attempted to solve these problems by applying the first shifting theorem (s-shifting) followed by the second shifting theorem (t-shifting). However, this method seems to lead to incorrect results. Answer said that t-shifting first, s-shifting later. Could you explain why this approach fails? What is the significance of the sequence in which the first and second shifting theorems are applied? When both shifting theorems are necessary, which should be applied first, and how does the order affect the final result? Thank you for your time and assistance. | 0 |
I have read about wave propagation and dipole antennas here. I do not understand how a single electromagnetic wave (i.e. the electric field in particular - I can come up with the magnetic field later) propagates when its electric field of a dipole antenna is shown below. For example, the iconic picture of an electric field of an electromagnetic wave looks like the figure in the bottom left corner in red below. How does it look in the bottom right diagram? I tried to plot it below again in red, but it doesn't make sense to me. For example, the amplitude of the wave would get bigger. So, I would like to know how a single electromagnetic wave propagates in this field. | 0 |
In the following sentence is "painted" being used transitively or intransitively? The sunset painted the sky with a tapestry of fiery colors. I asked ChatGPT about this and it gives reasons for both... For intransitive that it's being used metaphorically or poetically; the focus is on the action of sunset creating a visual effect, not the application of paint. When I reminded it that "the sky" certainly seemed to be the direct object it agreed at first that it was actually transitive. Yet when asked to confirm, it stated it was intransitive. Then it finally stated it's a matter of interpretation. Personally, I think it's transitive. Am I right? | 0 |
I want to make a program that will solve polynomials, but I don't want to just look at another program that already works as I think that would defeat the purpose of the exercise. And that's why I'm asking the question here instead of on Stack Overflow. I think it would be very difficult to implement Alpha-Beta Theory/Veita's Formula, and guessing using Factoring doesn't seem like a neat solution to me, so I'm wondering if there is in fact an easier implementation. I would also like this to be scalable for higher degree polynomials if possible. Thanks. | 0 |
I'm reading the famous paper by Haah: Local stabilizer codes in three dimensions without string logical operators. In the last sentence of the introduction, he wrote: A logical operator is a Pauli operator possibly with infinite support that commutes with every generator. Since each generator is local, the commutation relation between the generator and an arbitrary Pauli operator is well-defined. Why the locality guarantees the commutation relation is well-defined? Are there examples where removing the locality condition yields a not well-defined commutation relation between the logical operators and the generators of the Hamiltonian? | 0 |
I'm studying nonlinear control systems and I have some questions about the nature of this optimal control given by PMP: Traditionally, control methods based on Pontryagin's Minimum Principle (PMP) and Euler's method (or Runge Kutta) have been extensively used to address nonlinear system control problems. Is there a potential to get trapped in local minima resulting in suboptimal control outcomes? If there is one, why do we call it "optimal"? | 0 |
Solving Fresnel integral for vortex beam diffraction is necessary and difficult. Without the necessary integral formula, this isn't easy to derive. Therefore, I need some means to calculate it numerically quickly. I have learned some methods, such as angular spectrum method, fast Fourier algorithm. But I still can't understand its principle and implement it through matlab programs. I think I may need some correct codes or related books to learn, and I also hope to get a good explanation so that I can understand them better. | 0 |
Just a quick informal Question. I was wondering if the boundary of an LCF Manifold is also LCF ? By definition a LCF manifold is one in which, for each point, there exists a neighborhood around that point that can be conformally transformed to a flat Euclidean space. Since the boundary is a submanifold the answer to the above question should be, yes ! Do I have to be careful to which EUclidean Space i send the conformal transformation? i.e should boundary points only be conformally mapped to an euclidean half space? Thanks for clarification! | 0 |
Most articles show the plural form of equivalence as equivalences. The wikipedia on logical equivalence uses this form. However, I feel like I have seen equivalencies used in contexts like mathematics as well, like in this paper Equivalencies in Mathematical Structures: An Exploration through Model Theory and Groups Is the choice region specific (American vs European), domain specific (mathematics versus general conversation or other technical fields), or just whatever the writers preferred? | 0 |
Let's consider a glass slab ABCD. Now a light ray is incident on the near end of the air-glass interface AB and is emerging from the glass-air interface BD. In such a manner: Is there something wrong how I have made my figure. Can light emerge in such a manner from a glass slab. This is my first question and English is not my first language I hope you understood my doubt. I feel like the figure I have drawn does not look like the conventional ray diagram of light entering a glass slab. Also I am not an expert I am just a student who wants to know the answer to my question. | 0 |
I have a huge .bib file that contains all my references. Very few of them currently have a doi field. Given access to an online database that includes many of the same references, is capable of generating .bib entries, and includes dois, is there any more or less automatic way of using the database to add dois to as many of the references in the .bib file as possible? Note that the citation keys in my .bib file and those generated by the database are not identical, so matching would have to be done by e.g. title and author. Answers using e.g. Jabref or Zotero are fine. It feels like one of those tools ought to be able to do this. I just don't know how. | 0 |
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