Rocket launches are notoriously loud. So much so that measures are taken to prevent the noise/vibrations from damaging the rocket, the pad, or basically anything else within a few hundred meters. How much actual energy is carried away in that noise? (for the sake of specificity, in a Falcon 9 lau...

I was imagining the scenario for a story where the USSR still forms and will later fight in a Cold War with the USA. However, I am imagining a scenario where the tsar escapes, goes with some loyal followers to another location (on Asian continent or other location) and is able to establish a grea...

I am refinancing my first mortgage (no cash out). The new loan amount is about 58% of my purchase price (purchased 14 years ago). The loan amount is also about 52% of an appraisal I paid for 5 years ago and 44% of a more recent property tax valuation. And, get this: The loan amount is only 96...

In simple electrical circuits, the total resistance of parallel resistors can be found by $$\frac{1}{(1/R_1 +1/R_2 +⋯+1/R_n)}$$ Then this can be done with product-over-sum e.g. for two resistors; $$\frac{R_1R_2}{(R_1 + R_2)}$$ and for three resistors; $$\frac{R_1R_2R_3}{(R_1R_3 + R_2R_3 + R_1R_2)...

If I am interviewing for companies A and B, and company A makes me an offer but I don't want to commit without knowing the result of the process with company B, what is my best option? Option 1: Accept company A, and stick with it (even if it means posteriorly having to decline a possibly better ...

I'm going to be painting my garage walls this weekend as part of a project to turn it into a home gym. As I'm working on the walls, I noticed a lot of nails that are halfway in. Is this on purpose? Should I pull them out? Or hammer them in? Or leave as is? Home was built in the 70's. We moved in ...

I came across the following statement regarding true random number generators (TRNG): A “P1 medium” [AIS31] true random number generator (TRNG) may not be directly used due to cryptographic reasons. Even smart cards or other advanced security solutions which possess high-quality physical sources ...

Take a modern setting and a character with a good working knowledge of physics and no fear on telling people about whatever supernatural stuff they've found. As the only piece of magic in the setting, suppose that they are given a large branch of wood that burns eternally and produces smokeless b...

Does anyone know about the development of agglutinative languages out of fusional languages, or, more precisely, agglutinative features out of fusional features? I am thinking in particular about the development of Nepali out of Sanskrit or the Sanskrit-derived fusional language that was a mother...

I have hundreds of Mathematica notebooks accumulated over the years, and I'd like to search over them. I've been using various versions of text search (grep, SilverSearcher, Spotlight), but there are limitations. For instance, just now I needed to find where I have used the utility function toc. ...

How to change color and size at the same time of some vertices of a graph? I am trying to do it more than an hour but nothing seems to work. I can do it either for color or for size but not both at the same time. I want to have big blue disks. HighlightGraph[GridGraph[{3, 3}], {1, 2}, VertexSize ->...

Background I've worked with my current employer (Ontario division of a large tech company) for about 5 years now. For the past 5 years, I've been in a "senior engineer" position, but for the past 24 months, I've taken over for the "chief engineer" for the division, and routinely take over for my ...

When discussing a theoretical distribution having a single parameter described as a degree of freedom (like the $t$ distribution), do we refer to this parameter as degrees of freedom (plural) or degree of freedom (singular). We frequently see expressions such as A t test with 10 degrees of freedo...

Let's say we have 2 predictors $X_1, X_2$. And there are $n=5$ samples. Say we have the following values for $X_1, X_2$: $$ (1, -5) \\ (2, 0) \\ (3, 4) \\ (4, -3) \\ (5, 1) $$ $X_1$ and $X_2$ here are clearly orthogonal. If we include the intercept and introduce a column of ones, we find that for...

In a transaction that eventually calls revert(), if prior to the revert we have SELFDESTRUCT some contracts and thus received a gas refund, does the gas refund also get reverted?

I am beginning my journey on trying to understand a little deeper on signal processing. I wonder if the effect I am seeing is worth any spit or is there a deeper level of understanding is apparent I do not grasp. I was initially using Jupyter Notebook to make some examples of Aliasing so that I c...

In the diagram shown bellow we have 1.5 bit ADC stage. We have Vin which is an analog signal and it could be translated as 00, 01, or 10. In one bit we have only the option of 0 or 1. I can't see how it fixed an error, it's just dividing the range to more logical sections. I can't see any error f...

I see that there are many questions on whether putting/putting how many affiliation(s) on a paper. My situation does not quite fit into all the existing questions, so I am posting my question here. First of all I am currently working as a part-time lecturer at two different colleges in the same c...

In our analysis class, we just proved the complex conjugate theorem - that for any polynomial with real coefficients and a root $z$, $\overline{z}$ is also a root of that polynomial. I searched online to try to find a generalization of this fact, and ended up piecing together something like the f...

I added a particle property to a plane. I added a collection of 26 objects to particle system and attached it to particle property of a Plane. I was expecting all the objects to be displayed over the plane. But I am seeing that many of the objects are getting displayed out the surface of the pla...

Using only 2, 7, and 7 (each one must be used only once) and only using the operations +, -, *, /, ^, and parentheses, make 8. You can also use decimals

I have Kukemssa Pirates and several copies of Ashnod's Transmogrant. (Plus Cloak of Mists and similar cards.) If I attack with my pirates and they aren't blocked, can I use my transmogrant before triggering the pirates' ability? In other words: Attack Not blocked Use transmogrant to beef up opp...

So I recently picked up the PF-2e core book, and I noticed that Intimidate as a skill has a lot more built-in support than it had in PF-1e, having both rogue and a fighter feats dedicated to it in the core book, specifically, the Demoralize use of Intimidate. Demoralize: With a sudden shout, a w...

I came across the following question: Show that $(a, b:a^3 = 1, b^2= 1, ba=a^2b)$ gives a group of order $6$. Show that it is non abelian. Is it the only non abelian group of order $6$ up to isomorphism? I managed to prove everything except the last statement. How could anyone prove the group ...

Concerning the ordinary differential equation $$y' = \frac{(y^2 - 4yt + 6t^2)}{t^2}$$ with initial condition $y(2) = 4$. My text book gives the solution as $y = 2t$, and so does MATLAB. However, I only see the following : \begin{align} v &= \frac{y}{t}\\ y' &= v^2 - 4v + 6\\ tv' + v &= v^2 - 4v +...

Anyone have any good resources you can point me to find additional symbol libraries that are published for qgis/sld? My preliminary search has turned up a lot of plugs for the Resource Sharing plugin, but unfortunately, there really isn't much in terms of complex line styles. For context, I'm loo...

I want to rent a host that support 8 addon domains. I will use the Cloudflare CDN for my domains. Please tell me is that possible for others (people or robots) to identify my other websites? Thanks

I'm in the US. I will be installing a 240v outdoor outlet for an EVSE (electric car charger). However, in a few years I will have a garage built (elsewhere) and will move the EVSE, won't need the 240v outlet anymore. At that point, I will instead use that outlet for my workshop and would like to ...

I'm trying to understand Salesforce's locking mechanism. I ran a test which does the following: Calls Database.setSavepoint(). Issues a Select for Update query. Calls Database.rollback(savepoint). Delays for several seconds. Exits the transaction. I expected other threads to be able to access t...

This is a follow up to my previous post as it contained a lot of errors and wasn't accurate. I am using the Bubble sort algorithm to sort an array of integers and I would like to know whether I could optimize it in any way. #include<iostream> void printarr(int *arr,const int siz){ for(int i...

Neil Gaiman calls his "A Study in Emerald"* a Lovecraft/Sherlock Holmes fanfiction. And indeed it is exactly that: it uses the narration and story structure pretty characteristic to one from Arthur Conan Doyle's stories about the famous detective. The difference is in the background: in this stor...

I would like to create a boundary mesh of the following ellipsoid, whose thickness is modulated along its long axis: The surface parametrization I used for it is: {a, b, c} = {2, 5, 10}; s[\[Theta]_, \[Phi]_] := {a (1.2 - Sin[\[Theta]]), b (1.2 - Sin[\[Theta]]), c}*{Cos[\[Phi]] Sin[\[Theta]], Si...

I would like to simulate data based on real data captured. The real data captured is 15 observations. The simulation based on the existing data is 100 observations. I have a mean and standard deviation for the 15 observations, however how do I simulate standard deviation for a larger sample (100 ...

Both 勇気 and 勇 are nouns and mean courage. Does 気 give it a different twist? Couldn't you say 力と勇 instead of 力と勇気? (meaning power and courage)

I want to create a multi-color enabled debug-print command. As far I know, the only way to print multi-color messages in Vim is: echohl Macro | echon "Hi" | echohl Statement | \ echon " There!" | echohl None I plan to utilize this technique. However there's a main drawback of echon — it is...

Beginner question. I was reading about "resistors in series". https://www.electronics-tutorials.ws/resistor/res_3.html Perhaps naively I thought it would be possible to go buy a component which is already a series of resistors, but such a product does not exist. Why is this?

I have just read an article about that black hole merge event (it's in Italian): Sette miliardi di anni fa, due mostri si unirono What made me curious is that the article tell that a 66 solar mass black hole merge with a 85 solar mass black hole to form a 142 solar mass black hole. If the datas...

There used to be all these icons for each of your object in the Scene Collection window. In this picture, there's the visibility, selectability, and a computer and camera icon (not sure what those last two do). But in my current project (Blender 2.90), it only shows the eye (visibility toggle). ...

The under the counter space for the washing machine in our laundry room is slightly too low for our washer. I can't push it in any further because the enclosure isn't perfectly square and the washing machine is too high. I've already lowered the feet at the bottom to the lowest possible level. T...

Given matrix $$ C= \begin{bmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ x & y & z \end{bmatrix} $$ I want to put in the final row that makes it so the eigenvalues of the matrix are $1,2,3$. I know that the trace of C should equal the sum of the eigenvalues. Therefore $$z=6$$ I know that the determinan...

Does anyone know the name of a movie? I remember the plot of it. So it's a post apocalyptic movie where robots are hunting humans and there is two main characters a man and a woman. And it turns out one is secretly a robot that is being watched by the bad guys. They are trying to get to a place t...

Lately I have been learning about the replication crisis good youtube video, which according to Wikipedia "is an ongoing methodological crisis in which it has been found that many scientific studies are difficult or impossible to replicate or reproduce. The replication crisis affects the social s...

Looking at, for example, the bond lengths of styrene: Entity["Chemical", "Styrene"][EntityProperty["Chemical", "BondLengths"]] I get a list of three bond lengths: {Quantity[1.4, "Angstroms"], Quantity[1.4, "Angstroms"], Quantity[1.1, "Angstroms"]} But which bonds do these represent? I understand ...

optimization - MATLAB vs. Python in industry - Operations Research Stack Exchange contains this statement: I am a beginning PhD student in math, and I would like to focus on optimization. I am learning programming for the first time, … . How common is this situation? When I got my degrees in ma...

Theorem 19.5 in Munkres Let $\{X_\alpha\}$ be an indexed family of spaces; let $A_\alpha \subset X_ \alpha$ for each $\alpha$. If $\prod X_{\alpha}$ is given either the product or the box topology, then $$\prod \bar{A}_{\alpha} = \overline{\prod A_{\alpha}}$$ Proof. Let $x=(x_\alpha)$ be a poin...

I'm digging into the properties of the Local Vol model and I become confused with statements made by authors in papers/textbooks (without explanations) like, "The forward skew in local vol model flattens out" or "the local vol is not reliable to predict the forward skew". Denote the local vol det...

I need a 10w40 semi synthetic oil preferably shell helix brand. Having looked at their site the bottles seemed to be labelled ‘synthetic’ and not ‘semi synthetic’. However from the site it seems synthetic maybe referring to semi synthetic all of these seem to be listed under semi synthetic thoug...

I think in some media, light can be significantly slowed down but even if only slightly. Where would the momentum go when the light slows down and where it gets extra momentum when it leaves that medium? An example is a water.

When browsing Wikipedia, I came across this illustration that displays some of well known siege weapons of Roman empire. https://en.wikipedia.org/wiki/Siege_engine#/media/File:Roman_siege_machines.gif However, something in this illustration caught my eye and it was the second "Wooden shield/blocker"

I am trying to replicate this figure in latex. Obviously, it is quite easy to do it in Geogebra... but I was wondering if there is a special package we can use to do this sort of figures in latex. Many thanks in advance.

I don't like velcro straps on my bike. They are constantly shifting and rubbing against it. They catch dirt. They cover frame stickers ;) A few days ago I've seen a frame bag that appeared to be connected to the frame without any straps at all. Just like one in this answer: Photo Bikerumor I wan...

I want to write a custom function that outputs the Taylor series as follows: $$f(X)=f\left(X^{(0)}\right)+\nabla f\left(X^{(0)}\right)^{T} \Delta X+\frac{1}{2} \Delta X^{T} G\left(X^{(0)}\right) \Delta X+\cdots $$ $$G\left(X^{(0)}\right)=\left.\left(\begin{array}{cc} \frac{\partial^{2} f}{\partia...

In a magical world where mages can become immortal, why would some of them retain the appearance of being old (70s-80s), even though they can become young and beautiful? Even some mages who become immortal at young ages would change their appearance to become older. Why would they do that?

This particular question was asked in masters exam for which I am preparing and I could not solve it. Question: (a) Prove that if $G$ is a finite group of order $n$ such that for integer $d>0$, $d\mid n$, there is no more than one subgroup of $G$ of order $d$, then $G$ must be cyclic . (b) Using...

In Example 4.3:Gambler's Problem of Sutton and Barto's book whose code is given here. In this code the value function array is initialized as $np.zeros(states)$ where states $\in[0,100]$ and the value function for optimal policy which is returned after solving it with value iteration is same as t...

I think this adjective (形容词 ) only exists in Cantonese? Google didn't return official dictionary website. 粤语里的“作状、单打”是什么意思？_百度知道 作状就是装b，丑人多作怪的意思；单单打打就是说话难听，尖酸刻薄，指桑骂槐，含沙射影 I stumbled this 形容词 in comment under 【廣東話】獲頒友誼小姐唔得閒慶祝 鄺美璇：覆咗成晚MSG - YouTube 反而覺得好作狀 尤其啲尾音 I think this means On the con...

I want to run for example this command : ip addr on my remote system. I do it like this : ssh username@ip ip addr but I got this error : bash: ip: command not found when I connect to remote system and then run this command it is ok, I mean it is not caused by uninstalled package. I want to get...

Let's say I have deleted a file accidently a few days ago and I have discovered my mistake right now. Is it possible to restore this file, when it was inside of the iCloud-folders? In case a restore is possible: How long is a file-restoration possible, starting from the day of deletion on back...

NASA News item Ground Segment Testing a Success for NASA’s James Webb Space Telescope says: Testing teams have successfully completed a critical milestone focused on demonstrating that NASA’s James Webb Space Telescope will respond to commands once in space. Known as a “Ground Segment Test,” thi...

I want to implement the quantum Uhlmann fidelity $$F(\rho, \sigma) := \mathrm{tr} \left[\sqrt{\sqrt{\rho} \sigma \sqrt{\rho}} \right]^2.$$ in Mathematica as a measure of "closeness" between two density matrices. However, I think that my implementation is wrong. $$fidelity[\rho\_, \sigma\_] := (\m...

Why does gravity act at the centre of earth and how does that happen?

An isosceles triangle $ABC$ is given $(AC=BC).$ The perimeter of $\triangle ABC$ is $2p$, and the base angle is $\alpha.$ Find the radius of the circumscribed circle $R$. Let $CD=2R.$ The triangle $BCD$ is a right triangle and we have $\angle BAC=\angle ABC=\angle BCD=\alpha.$ I am not sure how...

I am reading H. Sati and U. Schreiber's article "Proper Orbifold Cohomology" -- see https://arxiv.org/pdf/2008.01101. On page 2, there is a formula almost at the bottom of the page, with a leaning U after the integral (Borel space). Does anyone know what font this leaning symbol is written with? ...

Here is my spaceship and I want to add and emblem on its wings (exact position marked with red circles). How can I achieve that? White color is just a Principled BSDF. Any kind of help is appreciated!

Hello stackoverflow community. I am programmer, 29 years old, one thing I noticed with passage of time is that I'm not as ambitious, sharp and energetic as I was at the start of career. My job becomes more demanding as I age and requires learning new stuff everyday, something my brain started to ...

I am preparing an encounter of my players against a drow priestess of Lolth, a drow mage, and several regular drow and giant spiders. As the drow have been forewarned, they set up an ambush: The priestess cast Insect Plague on a spot 20 feet away from the entrance, and the mage cast Cloudkill on ...

Is there some philosophical basis for temporal coherence of our identity? I noticed that there were many changes in my beliefs and personality throughout my life, e.g. me from 2000 probably would despise the political positions of the present me. Yet me from 2000 was doing many good things for th...

Let one assume a set $M=\{a+b\cdot 2^\frac{1}{3}\big{|} a, b \in \mathbf{Z}\} $. Is this a ring? As for me it's not, maybe because multiplication doesn't necessarily keep the product in M, but I can't prove it. Does anybody know, how to do this?

I'm trying to wrap my head around this command: find /home/ -type d \( -perm -0002 -a ! -perm -1000 \) 2>/dev/null I understand that it's going to look in the 'home' directory for all directories and redirect all stderr messages to a file (to suppress them), however I'm confused by the part in t...

(Anywhere that text is italicised indicates my uncertainty to the claims veracity) I'm searching for an anime (Japanese-style animation) movie/series (although it felt more like a feature film), that I remember watching a portion of before 2006 (Most likely watched it on mainstream television in ...

Let $G$ be a group of order $75=3 *5^2$. How many Sylow subgroups does G have? $|Syl_5(G)|$ has to divide 3 $\Rightarrow$ $|Syl_5(G)|\in \{1,3\}$ BUT $3\not\equiv_51$ $\Rightarrow$ $|Syl_5(G)|=1$ $|Syl_3(G)|$ has to divide 25 $\Rightarrow$ $|Syl_3(G)|\in \{1,5,25\}$ BUT $5\not\equiv_31$ $\Rightar...

Context: When modeling anisotropic particles, the two common types of shapes of interest are cylindrical and disk-like particles. For simplicity let us say we model these as prolates and oblates respectively (see below). With increasing aspect ratio, the oblate becomes more and more disk-like, w...

I have a character who has a super power that gives them what can be best described as perfect pheromones, and when in their presence, anyone will volunteer for anything they want. (Eg in existing fiction: Lucius Lavin) The proposal need not be verbal, there is some telepathic component to it. Si...

How come the first spaceship was completely blocked by the shield around Wakanda while some of the alien creatures passed through in Avengers: Infinity War?

I have been asked to serve on the examination committee for a PhD thesis. It's in the area of machine learning. It's from a university in a developing country. My job is to provide a written report, recommending whether to award the degree (possibly with minor or major changes), or even not to pr...

How do you distinguish: C tone in 4th octave - flat Cb in 4th octave ? Or said other way around. Is the order of operations: (C4)b or (Cb)${calculate octave}?

I'm looking for a good tutorial about oscillator design (electronically) for transmitter. The problems with current tutorials are almost all provide only schematics, some explain how it works. But noone show how we determine the transistor (select beta, or frequency range), determine resistor val...

This question 40194 asks about work arounds to check and replace variable names which are invalid in a specific MMA function context. For that case testing using the function itself is the most reliable approach, but I'd like a more general method. Is there a builtin function or a more general wa...

I understand that for a double slit experiment the equation is $\lambda=xd/L$, which has come from the small angle approximation of $d\sin\theta = n\lambda$ by assuming that $\sin\theta = (x/L)$ and therefore can be subbed in. I don't get why this doesn't work for both single slit diffraction and...

To integrate $y=f(x)$ from $a$ to $b$ we break the function into small rectangles of width $dx$. So the $n$-th rectangle will be at a distance of $ndx$ from $a$ on the $x$-axis. Let there be t rectangles between $a$ and $b$. Therefore $b=a+tdx$. But $tdx$ will be very small for any positive Integ...

I want to get "Use Count" Panel to attach to My Panel, what should I do? I know its Class is "PARTICLE_PT_render_collection_use_count", as shown below. Hope to get help, Many Thanks!

We know that if a function $f$ satisfies $$\lim_{n\rightarrow\infty}f(x_n) = f(x_0),\qquad (1)$$ where $\lim_{n\rightarrow\infty}x_n = x_0$, than $f$ is continuous at the point $x_0$. But can we reverse this statement? What I mean by that is, if we already know that $f$ is continuous at $x_0$, ca...

I'm trying to add smart light switches (I was thinking of Shelly 2.5) to my appartment, but the problem is my lightswitch enclosure doesn't have neutral wires. It just has a live wire that enters the lightswitch, exits and goes on to the lightbulb. The lightbulb has a neutral wire which completes...

While we're all accustomed to using * as the multiplication symbol (not to mention other esoteric meanings in programming) it is of course not actually the correct symbol for multiplication. And yet, there is no × key on any normal keyboard. Given the lack of × I can see why * was the next-best c...

I'm applying for a job which is a step down from my most recent job, which I got made redundant from. THe job market is so brutal that I have no choice and I'll take any management job I can get at a FTSE 100 company like this one. How does the following phrasing sound: "I appreciate that this ...

I'm using Ubuntu 20.04 and default Python3 version is 3.8.2 but I want to use the Python 3.7.6 . I don't care if the Python 3.8.2 will be uninstalled or not. I only want to make sure every time I use python3 command it runs the Python 3.7.6 (instead of 3.8.2). What should I do?

I am putting road drop bars on one of my mtb's for the winter as a project that has Shimano 10 speed 1x Deore. My goal is to "simply"🙈😆 have road shift levers and hydraulic brakes with good shifting and braking performance. Here is my setup can some tech cyclist help me figure out my cheapest o...

The bike I am riding is an older mountain bike that is a cheaper model, likely from Walmart or somewhere similar. I picked it up at the flea market and have been doing repairs on it as a way to learn more about how bicycles work. I was in the middle of a ride when all of a sudden I lost the abili...

In David Tong's lecture notes on quantum field theory, at the bottom of page 138 he states that, regarding the coupling of the electromagnetic field to a real scalar field, there exists "no suitable conserved current... This means we can't couple a real scalar field to a gauge field". I don't und...

I would like to replace my 6800 FC 52/36 and 6800 FD with the R8000 FD and FC 52/36. I'd like to utilize my existing 6800 brifters, which operate flawlessly. Are the cable pull on the brifters (6800 vs 8000) identical such that the 0.4 mm difference in chainring spread between the listed chainset...

I have the following table, which is too wide for the page. Now I want to fit this table into this set page. Where shall I modify here? I tried to change {@{\extracolsep{5pt}}lcccc} into {@{\extracolsep{\fill}}ccccc} but it made no sense. \documentclass[12pt, a4paper, leqno]{article} \usepackage...

I have a file foo.txt with just a one line ab. I want to launch Vim in such a way that it will open this file, swap characters using xp, and then save it as bar.txt. Something like this: gvim foo.txt xp :wq > bar.txt I'm not sure it is possible. Any suggestions?

Let $S$ be compact oriented surface without boundary. Then it is a classical result that a primitive class $\gamma \in H_1(S; \mathbb{Z})$ is always represented by a simple closed curve. It implies that any class $\beta \in H_1(S; \mathbb{Z})$ is represented by a disjoint union of simple closed c...

Tell me why most cursive forms of Chinese character, "不", is shaped like this: Instead of this?: Looks like four dots. And another Chinese character, "正", shaped like this: Instead of this?: Why is this exists, Tell me how is this exists?!

This question came up because I read that Bolsonaro, Brazil's president, was criticized by the opposition for saying that COVID-19 vaccinations won't be mandatory. The opposition said that the vaccine should be a requirement. Specifically for the United States, is it possible that getting vaccina...

What's the difference between: fun <T, R> List<T>.map1(transform: (T) -> R): List<R> { return this.map(transform) } and fun <T, R> List<T>.map2(transform: (T?) -> R): List<R> { return this.map(transform) } and fun <T, R> List<T?>.map3(transform: (T?) -> R): List<R> { return this.map...

I go through waves, not quite a sea. I look for more, hope to find none. If my job were done, so would be carelessness. Who am I? Ty bobble for the title. I like your answers so far! You guys are so close!

I am measuring magnetic fields from 50kHz to 500kHz with this search coil (air coil.) It is a wound of bell wire from the hardware store connected to an oscilloscope probe tip and ground: I have built a new one with a ferrite core Fair-Rite 2631814002 with 1500 relative magnetic permeability for...