darklight03/StackMIAsub huggingface dataset:
Suppose a body is kept in space and is not fixed about any point (i.e, not hinged). If an external force is applied, the body rotates about the centre of mass. I saw one answer pointing out that moment of inertia is minimum about the centre of mass, and thus motion around any other axis is unstable. Is this view correct? And if true, how do we go about proving that it indeed is the most stable?
Both nematic transition and Jahn-Teller distortion distorts the lattice and reduces the symmetry of a crystal; both of the structure transition can take place at higher temperature than the magnetic transition. Why in iron-based superconductors it is called nematic transition, while in molecular system it is called Jahn-Teller effect? (Particularly in the papers talk about iron-based superconductor they never talk about Jahn-Teller effect.) Is there a deterministic experimental fact to distinguish the two? Thanks.
I'm writing a report. In the report we refer to program participants as either dedicated or auxiliary. Each has a unique situation in which they enter the program. Since they are a particular type of participant, I have been capitalizing them to avoid confusion, but I'm not sure if this is correct. For example: When Dedicated participants submit an application they must... Is this correct? I understand it as a proper noun. I'm confused about the rule as this comes up many times in reports I need to write.
What is the synonym/counterpart for the word "Default" in NON-IT WORLD? We use the word in computer programs/apps, meaning that there is a pre-specified/pre-defined setting or situation. The word has also different meanings in Law and Banking. But I want an alternative to use in our daily life: for instance, a physician may choose a "default" treatment for a common disease, or one can have a default position/view on a particular topic .... I want a counterpart meaning of the same word for everyday uses (non-IT world).
Could the gravitational effects of exotic matter be replicated by using something like a torus of mass around a point? Because spacetime is relative (I'm pretty sure), for observers on the torus, or just any celestial object i guess, would they not see the other points in spacetime around them having a negative energy, and repelling objects instead of attracting them? I know I've made some sort of misconception about this, but I can't figure out what it would be, except maybe spacetime not being relative. Edit: I drew an amazing picture to demonstrate what i was thinking
This is a snap of a textbook while describing Uniform Circular Motion. For all the diagrams, and by the vector law, the directions of the del(v) vector is perfectly fine. But I am confused why this del(v) vector will always be pointing towards the center. As it is stated here, just because v is perpendicular to r and v' is perpendicular to r', therefore del(v) is perpendicular to del(r) does not sound satisfactory. Any other logical reason why del(v) vector will point towards center only when del(t) is long enough as in diagram a and b.
Just wanted to question how Hilbert space dimensions work. From what I've seen, they're used to generalize the mathematics of finite-dimensional Euclidean spaces into infinite-dimensional vectors. I've seen them used in quantum mechanics, and in some cases stated to "inherit finite dimensional space-time" despite the Hilbert space having infinite dimensions. So I'm basically asking how Hilbert spaces correlate to the physical spatial dimensions they represent. Are there Hilbert spaces that represent topological spaces with infinite spatial dimensions? same question for any function spaces with infinite dimensions.
I'm not sure if this is the right community I could ask to, but I'm looking for a reference in business calculus that has challenging problems. The ones that I found so far have easy problems and can be solved within a day. I'm looking for problems that will probably take time to solve and will use a lot of thinking (and not just copy the methods/insert some formulas to solve). I would appreciate it if someone can recommend to me a reference that I'm looking for.
I'm trying to modelise the ping pong and water cup experiment. They were already questions on stackexchange about this: Why does a ping pong ball bounce higher when it is dropped together with a cup of water? but I would try an approach with Archimede Force and superficial tension. I want to apply Newton's law on the ping pong ball, but the water and the cup are moving too and I don't know how it works in that case or how to modelise it... What do you think about it?
I have some powder in a container with one side open. If I then compress it from that open side, does the powder evenly compress, or will the side closer to the opening (or furthest from the opening) compress more, and end up with a gradient of compression? For example, when tamping ground coffee in an espresso portafilter - is the coffee density even distributed through the portafilter, or will it be denser at the top or bottom? And what factors (if any) affect this? Regarding individual particles - shape? size? texture? uniformity? compressibility (of each particle)?
I recently delved into the topic about the reality of the Dirac string. Although several authors show how this object should not be real, this article "Field momentum and the reality of the Dirac String" proves they're wrong. I think the thesis of the article is very strong and I would like your opinion. I am writing my bachelor thesis on this study, I am learning both the Lagrangian and Hamiltonian formulation of the system to understand if I can find a solution, however the authors of the article seem to me to use only classical arguments. Any ideas?
I read about the 'Method of undetermined' in the wikipedia and it said as following: In order to find the particular integral, we need to 'guess' its form, with some coefficients left as variables to be solved for. This takes the form of the first derivative of the complementary function. Below is a table of some typical functions and the solution to guess for them. I can't understand the sentence "This takes the form of the first derivative of the complementary function" what does it mean? Is there any relation between particular integral's form and derivative of the complementary function?
I see the statement that: Similar to how a car needs fuel to run, a computer needs electricity to power it. In this case, I comprehend its meaning. However, I don't really get why "similar" is used at the top of the sentence here. If "similar to how" is an adveribial clause, my searches don't find any results or any envidence. Likewise, I can't figure out clearly any type of reduced relative clause.
I have read that if helicopter's engine fails, you set the pitch to minimum but not reverse pitch. The rotor would have to be tilted back to provide an angle of attack on the blades so it glides like a fixed wing aircraft but with the rotor spinning to keep the blades from buckling under the weight of the craft. I think it would have to go into a slight reverse pitch to spin the same way. That would also provide more angle of attack on the receding blades where it is needed because of the lower air speed over those blades. How does it keep rotating in the same direction with the air going up through it if it can't go into a slight reverse pitch?
I know that we have to use 'the' when it comes to groups of people, for example: The French are good at cooking. When nouns and adjectives are the same, we can omit 'the' Americans are good at sport. However, I do not know what to do with a word "Brit". I'd like to know Brits more OR I'd like to know THE Brits more? Can I omit the definite article?
In an electric circuit, electron flows from the negative terminal of a voltage source to the positive terminal, which in turn, gives us the the conventional direction of electric current. So, the first question that arise in my mind is: On moving to the positive terminal, does the electron gain stability? If it does, then we know that an electron moves from a higher energy level to a lower energy level it releases a photon of a frequency dependent upon the energy gap, to gain stability. The second question is: Why does an electron move towards a region of lower energy but in a circuit, towards higher energy (positive potential is obviously a higher energy level)
Suppose I have a rhombus based penrose tiling like the following: Is there some coordinate system that allows me to easily uniquely refer to a specific tile, and also from the coordinates efficiently calculate the coordinates of the tiles that border it? I also need to be able to easily tell what tile is on the "opposite side" edge of a tile with respect to a different tile that also borders it. Basically my end goal is, if I have some instruction like "Straight, Straight, Left, Straight, Right" and follow them on the grid to calculate if I ever cross my own path and when.
I am attempting to apply the Grubler formula (which can be found here: https://learnmech.com/how-to-calculate-degree-of-freedom-of/) to determine the number of degree of freedom, but it does not seem to yield the expected in some cases. Is it correct that there are some cases where the Grubler formula should be avoided? If yes, how can I recognize these cases and what method could I use instead? EDIT: I've edited it to only ask about the underlying concept as required. Now, one might say that it lacks an example where it doesn't work ... tell me if that is the case, I'm just trying to comply.
Interference is explained by showing a diagram of two parallel waves of light that are in phase or out of phase and showing the result of the fields constructively or destructively interfering. Implicitly it seems to be the case that they are polarised in the same plane as well. What I wanted to know is what this picture looks like when we're talking about unpolarised light. I'm reading about XRD and Bragg's, and can't seem to find any indication that polarised X-rays are used. And if that isn't the case, then even if two waves are in phase, the net E fields are polarised in random directions to each other and wouldn't undergo constructive interference. Where am I going wrong here?
The wavelength or frequency of light determines its color. Photons seen as particles are said to have a frequency, determined by its energy, so I assume that 'is' the same color. But being quantum particles, photons also have a probability wave, determining how likely it is to detect it in a certain state (like, a position). How do these waves relate to each other, if at all ? Iow, would the double slit experiment have a different result when performed with 'red photons' instead of 'green photons', and if so, how would it differ ? Sorry if I get things wrong, I'm just grappling with the nature of these things.
How strong of a gravitational field do you need for a projectile to make a full loop? By full loop I mean it curves once around the by dot, and then it ends up on the same trajectory as it was one before it approached. How many times the Schwarzwald radius would the projectile have to get for this to be possible? I know the limit in Newtonian gravity is half a loop.
I had the feeling that physics has moved on from the idea that spacially bounded objects located in spacetime (such as particles) can be fundamental. Instead, QFT describes everything by quantum fields which are better considered as an everywhere present property of spacetime rather than embedded in it. From this perspective, it always felt to me like string theory is a step back, talking again about bounded objects located in spacetime (i.e. "free floating strings", as this answer states). Question: Is there a flaw in my understanding? How can free floating bounded strings give rise to spacially extended quantum fields? I am a mathematician and fine with advanced mathematics, but am a layperson when it comes to physics (you might consider me as an undergrad in this respect).
I want to know the mean first passage time (MFPT) on a unit interval for two boundary conditions (please see attached figures a and b for your reference). This is in the context of the hydrodynamic dispersion of a particle. In case a) the b.c switch from reflection to absorbing whereas in case b) the b.c is reflective. Can anyone help me to figure out the mean first passage time in this problem?
I am currently looking for a cyrillic font (for russian typewritting). It must be an opentype font usable with lualatex and fontspec, and must be complete : roman, italic, bold, small caps, superiors letters and figures, in serif and sans serif. For all I know, Libertinus is very close, but it lacks cyrillic small caps and superior cyrillic letters. Does a more complete font exist?
I have a knot about the "secondary" colours and its spectra. So If I look the spectra of white light, I can see that yellow, which is between R and G, has some wavelength. If I do an addition of light of Red and Green, I get yellow. Ok. Now If I do an addition of light of Red and Blue, I get Magenta. But how come that Magenta is only a perception and has no wavelength, as Yellow for example ? I understand that some colours physically do not exist, but I dont understand why yellow exists as a real physical wavelength but not magenta. Can someone help please
According to Stephen Boyd's textbook on ADMM, the global variable consensus ADMM updates are given as the following, which is pretty straightforward to understand: However, I've recently seen another variation of the consensus-ADMM updates from this work I tried very hard to derive the primal updates shown above but I just cannot arrive at the same equation. I wonder if this is the same as global variable consensus ADMM at all?
So, I'm trying to make a basic shooter game in desmos, and I have a list of points that act as bullets. The (current) enemies right now are only some triangular jets that fly in a linear manner. My current goal is: Make it so when the point hits the triangle, it deletes itself from the list, and thus itself from the screen as well. The Triangle, upon getting hit, moves downwards in a curved path and stops when it hits the ground (a line). https://www.desmos.com/calculator/sjezpkhhxl Here is the graph itself. The lines for the bullets themselves are in the folder titled bullet and the lines for the triangle are labelled as enemy: fighter jets. If any more details are needed, please do let me know.
My wife mentioned today that she would love to know more about 'how the world is made up'. She stopped learning science at a young age and finds most stuff meaningless or incomprehensible. She is not a child - so the challenge is, how to introduce the history and development of atomic physics with minimal specialist vocabulary, in a manner that reliably explains how physics got to the standard model. Pictures are good, waffle is bad, mathematics and equations is a no, hand-waving or similar patronising (eg '...for idiots!') statements are a no. Her wish is aspirational - so the presentation needs to be reasonably effortless... Any thoughts or suggestions?
I remembered this really corny phrase today when I was on a walk but I forgot later before I could write it down. It's kind of like "You are what you eat" but with different words. It's not: You reap what you sow. You're the sum of your actions. Easier said than done. (It is a different one but they're both about contiguity. I don't remember what it is.)
Why does she try and pull the stunt? This is probably an elliptic sentence - Why does she try the stunt and why does she pull the stunt (off)? - but it still seems like very bad style to me. Why does she (even) try to pull the stunt (off)? I am aware that it is not clear that the attempt was successful, however the to-infinitive comes much more naturally to me, for whatever reason. From context, it is clear that it was successful. So, would you consider it weak style to use an ellipse like this?
I am trying to determine a statistical test to run. My dependent variables is employee retention. The independent variables are exam score and interview score. Unfortunately because employees who failed the the exam did not moved onto the interview, I do not have interview scores for all cases. Do I run a logistic regression? Is there any other test I can run to be able to use exam and interview scores to predict employee retention?
To my understanding, the curvature of spacetime is determined by the stress-energy tensor. I was wondering if we could calculate some of those components using radiation. Is it possible that objects that possess immense electromagnetic radiation, for example, will follow with a strong gravitational pull? Does radiation occupy physical space? Just had a thought experiment where I visualize spacetime like water that engulfs any solid object and doesn't go through it. But in my visualization, the actual spacetime didn't touch the solid object since the solid object occupies more space than its physicality. It engulfs the radiation and interacts with it. Just thoughts :).
So in my course of quantum computation i came across this question that "What guarantees a quantum gate to be unitary?" i was specially curious about photonic quantum gate. At first i thought that maybe unitary is not something that is guaranteed by any special phenomena but its inherited by the math behind quantum physics and that we use to describe any physical operation with an unitary operator but is it really the answer?
We need to solve this problem without using trigonometry. KLMN square is inside ABCD square. Prove that midpoints of the segments AK, BL, CM, and DN are vertices of a square. KLMN can be situated anywhere inside ABCD. I think that we are going to use congruent triangles. I tried to draw so that the intersection point of diagonals of ABCD and KLMN coincide, I also tried the opposite to consider the general case, because KLMN can take an arbitrary position. So, I would like to see approaches, how to prove.
I wonder if above some energies (or diagram level?) the virtual particles would rather behave (or become) like a micro black hole. Does that make sense? Could this somehow introduce a cut off above which Feynman diagrams would be unnecessary (the micro black holes would always evaporate in perhaps a few different ways), and in doing so avoid renormalization? This are speculations from a freshman, so please don't be hard on me.
An oxymoron is a figure of speech in which contradictory terms appear in conjunction with one another. Can there be a figure of speech in which similar compatible terms appear in conjunction with one another? For example, how would I describe the following sentence? Nice should be great. Nice being the location, but also a compliment. Play on words? Comedic effect? Feel like there isn't one and idiom or a proverb doesn't quite fit.
As my title says, is a "change in scenery" as correct as a "change of scenery"? I am self-conscious of how a "change in" might sound odd or off or be even absolutely incorrect. Are both forms of this sort of expression truly correct? I know the latter one is (a "change of scenery" makes full sense), but what about the former version of this idea with "in" as its preposition instead of "of"?
So there's this debate ongoing on one post that this phrase is incorrect. People are getting confused and wondering how can Adele take a divorce from her own son. The sentence is: Adele says new album will explain her divorce to her young son. Is the above sentence correct? I always thought a divorce was taken from someone and not to someone. For context, the sentence is being used a headline caption for an image.
If all bodies emit thermal radiation, does it mean that it's impossible to build something that can retain all of its energy - and last indefinitely? i.e. is everything in our world, including a dynamic, living system that can self-repair, eventually gonna collapse? OR - there is something in Thermodynamics similar to Superconductivity in Electromagnetism that would help prevent this? OR if there is no such effect, is there, even theoretically, a way to mitigate the effects? I can only think of creating new energy within a system faster than the system can lose it due to thermal radiation, but doesn't this violate conservation law(s)?
I'm looking at an example system which has a very large number of microstates (effectively infinite - not possible to enumerate exhaustively, but possible to sample from). The energies of the microstates however are drawn from a normal distribution with some average energy and standard deviation of the energy. What is the partition function for a system like this expressed in terms of the average energy and standard deviation of the energy? What is the entropy?
If the vacuum energy of the universe is not at its minimum, that is, the universe is at a false/metastable vacuum state, then it could decay into the true vacuum state. However, if our universe is already at the true vacuum state, then, this decay would not take place. However, in the far future, if we would wait enough time, could the true vacuum transition into a false vacuum level somehow? Or is this utterly impossible?
I was thinking of converting a disused chimney into a static periscope, using long focal length lenses at top end of the chimney. A static design would be easier, so I was wondering how one would design the mirror shape such that it converted a cylindrical view onto the lens, which could then be processed at the other end of the chimney to generate a cylindrical view once more. Is it even possible?
Assuming right to be positive, in this question, is the work done by the boy positive or negative? I would think it is negative because the force that the boy exerts is towards the left while the movement of the boy is towards the right. I would think that work done ON the boy is postive because the force that the string exerts on the boat is towards the right which is the same direction as the motion of the boy. Am I correct? I don't quite understand how to think about the idea of work done BY the boy in this context. What does it mean for work done BY the boy to be negative?
I'm looking for open books on abstract algebra, other than Judson's AATA. I want one with a good number of exercises (and solutions, preferably), this one covers the rest. Does anyone know of one? This and this are similar questions. The first one has many answers and the second is markedly different, but answers specific to abstract algebra, with brief descriptions of each book (too much to expect in the first) might help someone someday.
So I was wondering if it was possible to prolong the "entropy" of the bottle by making sure the heat of the contents of the inside of the bottle doesn't escape by first having a secondary bottle on the inside of the existing container. Then there would be a vacuum. So would the heat stay trapped if there were mirrors on the inside of the outer container bouncing infared radiation as it gets radiated from the inner container. Is this a means of preventing entropy increase in the universe, so could be used with dyson spheres to trap heat preventing it from escaping in the distant universe to preserve more energy? Are there any issues with this approach?
According to numerous questions (e.g Is it recommended to use "we" in research papers?), one should use "we" instead of "I" while writing a scientific paper. However, it's unclear to me if, for example, "In the following image you can see..." should be replaced with "In the following image we can see..."? Personally I think, that the latter sounds better and also includes the reader together with the authors in the discussion at hand, as already mentioned in the above question. But it's still unknown for me, if it could or should be mentioned while reviewing another paper.