Electrodynamic tethers have been proposed for satellite propulsion in the magnetic fields of Earth and the Gas Giant planets. Is it realistic to consider using the solar magnetic field for electrodynamic propulsion in the inner solar system? The heliospheric magnetic field is stronger than Jupite...

I am using the Layer Properties to categorize a large dataset by two attributes: manufacturer material "Manufacturer" + ' - ' + "Material Type" It's returning a long list of combinations as expected. However, I would also like to see the total count against each category in the Layer Propertie...

So I was looking through the homepage of Youtube when I found this video by Cipher. The question proposed in the video was$$\text{How do I find the last }4\text{ digits of the sum of }2+22+222+2222+\dots+\underbrace{222\dots222}_{1042\text{ digits}}\text{?}$$which I thought that I might be able t...

I am trying to select the faces that wrap around my object like this: But i would like to do it for these areas: But when I try to do Alt+Left Click, this is the result: If I'm lucky, one in ten times, I will get this, which is what I want: What buttons/settings am I supposed to press/have to...

I'm trying to install AFCI breakers on my kitchen SABCs (2x 20A circuits), in my Square D Homeline panel. Unfortunately, the breakers trip whenever I try to do anything useful on those circuits. I've spent hours going over all the wiring inside the boxes and making sure connections are tight, con...

Consider two tables: Tab1 = RandomReal[{0, 1}, {10, 8}]; Tab2 = RandomReal[{1, 2}, {10, 4}]; I would like to replace the 5th and 6th columns of Tab1 with Tab2, i.e., Tab3 = Join[Tab1[[All, {1, 2, 3, 4}]], Tab2, Tab1[[All, {7, 8}]], 2]; Is there any other way of doing this?

Okay, I'm trying to make a planet that has at least part of its surface, or at least part of its underground, habitable for humans (breathable atmosphere at a suitable pressure, a suitable level of gravity and radiation, and a suitable temperature). The plants here are white in color. What kind o...

(The question is very ambiguous, here is the actual scenario I am talking about. I will rename the question, if its required in future.) If I am standing still and I produce a sound pulse in direction perpendicular to me, and then I start moving, my sound will move in direction perpendicular to m...

My code: module adder(a,b,result); input wire [9:0] a,b; output wire [10:0] result; assign result = a + b; endmodule My company recently changed policy to escalate the linting rule (W164a and W164b) mismatch of LHS and RHS bit widths from warnings to errors. Now I either have to waive t...

Part of the Monthly Topic Challenge #10: Möbius Strips, Klein Bottles, and other unusual topological surfaces +--->--->--->---+ | o | r | t | h | ^---+---+---+---v | n | o | g | o | ^---+---+---+---v | a | l | l | y | ^---+---+---+---v | y | l | n | o | +---<---<---<---+ +---+---+---+---+ | a ...

Problem I have a multi-qubit state $\lvert \psi \rangle$ and an ancilla qubit $\lvert 0 \rangle$ that I use to extend my state, getting the new state $\lvert 0\rangle \otimes \lvert \psi \rangle$. Suppose now I apply a generic unitary operation on this state and get a new state $$ \lvert \phi \ra...

I want to download the Linux kernel and unarchive it in one step. There are a lot manuals about it. So I tried: $ wget https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.3.1.tar.xz | tar -xav -C /home/a/myKernel/ --2023-05-06 03:04:38-- https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.3.1...

I recently started learning German and got into some of the details of German grammar. I know there are several different ways of expressing events that took place in the past. I learned the following equivalences: German English Präteritum Simple Past Perfekt Past Perfect As I am l...

When the compound is chlorinated on the extreme carbons, there is a chiral carbon in both the resulting compounds, which gives a total of 4 stereo isomers. When compound is chlorinated on 2nd or 3rd carbon, it still has a chiral carbon in both resulting compounds. So the total stereo isomers add...

I am stuck on the following problem and would appreciate some help solving it: The number $\sqrt{\frac{2-\sqrt{2}}{2+\sqrt{2}}}$ is equal to (a) $\tan \frac{\pi}{4}$; (b) $\tan \frac{\pi}{8}$; (c) $\tan \frac{\pi}{12}$; (d) none of the above. I have tried simplifying the expression and using vari...

Being not a philosophy scholar, I am trying to get up to speed on the nature of statements about basic, established facts in human knowledge and how these relate to the existance of rare exceptions. For instance, consider the current Encyclopedia Britannica page for 'tetrapod': All tetrapods sh...

I'm curious if there are any common parametric distribution models for mixed discrete/continuous data. For illustration, suppose I have two random vectors, $X_c,X_d$, where $X_c$ is continuous and $X_d$ is discrete. I have data consisting of samples of $(X_c,X_d)$, and I'd like to do some densi...

On an Earth-like planet, we have a functionally human-like creature which evolved to dwell comfortably in its world's boreal forests. As humans have done, it will likely have a desire to explore its world and find new places to live This raises the question of temperature: Unlike with humans, the...

I create one global clist and assign 4, 300 as the two elements to it. \clist_count:N shows its 2 elements. If I copy this clist to a local list the contents of the new list are identical but \clist_count:N shows only 1 element. Why is that? \documentclass{scrlttr2} \ExplSyntaxOn \clist_clear_n...

Sufficiently strong electromagnetic pulse can/will destroy smartphones and computers. I know somebody who went into MRI machine and forgot VISA credit card in his pocket. Card was toast and he had to get new one. Mobile phone in MRI probably wouldn't fare better. But big part of human body itself...

I was searching for a circuit that would detect 3 phase sequence and give dry contact output if the sequence is correct. I have found the schematic below, from a Daikin compressor manual. I wonder if this will work if I assemble it? As you can see all part of the elements value table given abo...

Consider an association assoc := Association[{"a" -> 1, "b" -> 2} ] How to invert it, i.e. to obtain assocInvert:=Association[{1->"a",2->"b"}]

The model I have is Whirlpool ADG 7570. It does not wash every object in the machine as good as it should. When I start the machine it seems to be taking in water as normal, and it make normal washing, but it does not do that for too long. Repeat: After a few minutes it stops and make a very low ...

My Spanish is weak, at best. But I like the legroom of an exit row. Does Avianca really limit exit row seats to Spanish speakers?

I'm reading some Shakespeare and noticing past tense verbs are written as deceiv'd and search'd etc rather than the modern deceived and searched. When did the shift take place in English to the modern way of writing it? Do we know how it happened?

When using AES-256 (cipher mode CBC and padding mode PKCS7) in combination with HMAC-SHA for authenticated encryption (assuming alternatives like TLS and AES-GCM cannot be used), should we use SHA-256 or SHA-512? This answer seems to indicate SHA512. Is this interpretation correct? I've seen an ...

I know that two sentient species can evolve from the same origin. We can look back and see Humans, Neanderthals, and others living at the same time. But Humanity either beat the others or interbreed with them and came out on top. I would like to know the probability of two creatures of similar in...

Inspired by the Biology SE question Was there a flu season in paleolithic times?. From Wikipedia's Paleolithic: The Paleolithic or Palaeolithic... also called the Old Stone Age (from Greek: παλαιός palaios, "old" and λίθος lithos, "stone"), is a period in human prehistory that is distinguished b...

I have a small robo dwarf hamster. He's getting older (maybe ~2 years old?) and I'm trying to figure out how to enjoy him instead of just cohabitating with him. He's a very cute little guy, but not super interactive. To be more specific: He will stand on my hand to grab food, but will not approa...

家に辿り着くまで通行人の視線を感じるわ、寒くて風邪を引きそうだわで散々だが致し方ない。 What exactly is だわで here? Google suggest it may be some kind of grammar, but it's not clear. This is narration from context 家に辿り着くまで通行人の視線を感じるわ Here mentions (because he was all wet) until he got home he felt the gaze of the people 寒くて風邪を引きそう the cold, ...

In Russian, there are a lot of peculiar color names, one of them being цвет детской неожиданности, literally, "baby's surprise" or "child's surprise". This is a shade of yellow that a newborn baby's poo has. Most sources put it as #F7F21A or close to it (https://get-color.ru/#F7F21A), but of cour...

I am working with the attached circuit, sourced from here: Original This circuit is designed for a single sided power supply and has worked very well for me in the past. For a new project, I would like to use it with a dual sided power supply, providing -6V, 0V, and +6V. Ignore the "precharge" ...

The projection of line $$\frac{\mathrm{x}}{2}=\frac{\mathrm{y}-1}{2}=\frac{\mathrm{z}-1}{1}$$ on a plane ' P ' is $$\frac{\mathrm{x}}{1}=\frac{\mathrm{y}-1}{1}=\frac{\mathrm{z}-1}{-1}$$ Determine the equation of plane. What I tried: Clearly, $(0,1,1)$ lies on both the plane and line. $$\cos\th...

In German we have the idiom "doing handstands". It describes an unacceptable amount of effort: The circumstances require it, but they themselves are considered unacceptable. Two examples: Nowadays, pupils have such a short attention span that teachers need to do handstands to keep them engaged. ...

I am trying to create three road symbols with TikZ. These are US Interstate Shield US Highway Shield Generic State Highway "pill". This is basically a rectangle capped with two semi-circles. I have created a package like so... \NeedsTeXFormat{LaTeX2e} ...

$$\frac{dX_t}{X_t}=\alpha\frac{dS_t}{S_t}+(1-\alpha)\frac{dS^0_t}{S^0_t}$$ where $\alpha$ is proportion of the investment in the risky asset $S_t$ , and $S^0_t$ is the risk-free asset. $S_t$ follows a geometric Brownian motion, $$\frac{dS_t}{S_t}=\mu{dt}+\sigma{dW_t}$$ $$\frac{dS^0_t}{S^0_t}=rdt$...

I'm new to Blender and I've been trying to attempt to create a low-poly character and I came across this speed build video where one was able to instantly transform a set of vertices into a hexagon shape so they can make the arm. Does anyone know how to do that like in the gif below? What are th...

I purchased two "Advanced Single" tickets for May 20 on March 2nd and paid just £5! Bargain, yes. Today I've been informed: Unfortunately, Great Western Railway has let us know that part of your journey from London Paddington to Oxford on Saturday 20 May has been affected by a change to the tim...

I was trying to get the GCD of two numbers. This function I saw on github works fine but I have a confusion here. The function : function _gcd(uint256 a, uint256 b) external pure returns (uint256) { uint256 _a = a;//65 uint256 _b = b;//784 uint256 temp;//0 while...

Today, I went out for a ride and had a small crash. I fell down sideways, then came home and realized there’s a small paint chip (which i’m fine with it) but there’s a small dot which is the deeper one that shows some brown colour. Did I damage the carbon? Left-side of frame, opposite side to r...

Let $W(\alpha)$ denote the set of all (countable) ordinals writable by Ordinal Turing Machines with a single (countable) parameter $\alpha$, i.e. each computation starts with a single ($\alpha$-th) cell on the input tape marked with a non-zero symbol (all other cells are marked with a zero symbol...

Non cyclic subgroup of nonzero rationals under multiplication: My motivation to question is curiosity. Moreover,this would be another proof that the set of non zero rationals under multiplication is not cyclic group. I see that set of dyadic rationals is subgroup of rationals under addition, so, ...

I have a file format.sh in linux os. There are five users a, b, c, d & e. How can I set the file permission for different users: a -> Read, Write & Execute b -> Read & Execute c -> Read d -> Execute e -> No permission I have familiarity with basic file permissions modification using chmod, chown &

I am working with the local-setup and I have a smart contract to vote for a provider. In my schema: structs: Proposal: provider: String # provider name value: Uint64 # service value votes: Uint64 # votes amount state: proposals: Proposal[] and I have a funct...

Why am I getting 5V at point A? The microcontroller IO is 3.3V.

My professor mentioned in class that every vector space has at least two subspaces: itself and the zero subspace. When I asked him if this rule was an exception for the zero vector space, he thought about it and said no, followed by a reason which I didn't understand then and don't remember now (...

Background I am trying to understand a historical engineering drawing intended for machinists producing a part. I am neither an engineer, nor a machinist, and have only a basic understanding of such drawings. As is apparently typical for such drawings, they contain measurements related to differ...

William Blake's "Auguries of Innocence" starts with a quatrain whose relation to the rest of the poem is not immediately apparent to me, describing a powerful kind of vision/imagination which transcends normal ability: To see a World in a Grain of Sand And a Heaven in a Wild Flower Hold Infinity...

After looking at the derivation of Cauchy's stress formula, stated as: $$ \vec{t} = \sigma \hat{n} $$ I've reflected upon the derivation and some questions have arised. I state them below: First of all, why are we using tetrahedrons in our derivation? Are we limited to this geometric shape, or i...

I'm using this grid of strips as the rubber flaps you see on airport luggage scanners. It currently has a cloth simulation applied to it. I was wondering how I could increase the vertical resolution of the flaps so that it doesn't looks so segmented. Subdivision Surface modifier and shade smooth...

I am trying to solve a equation whose degree rises as n rises： n = 10002; equ = -b; Do[equ = equ + (1 - b) v^i, {i, n - 1}]; vs = Solve[{equ /. {b -> (n - 2)/n}} == 0, v, Reals]; Do[If[0 <= vs[[j, 1, 2]] <= 1, fans = vs[[j, 1, 2]]], {j, Length[vs]}]; fans = vs (1)I am looking for the real answer...

In QGIS (Version 3.22), if I need to change (reduce) the resolution of a raster layer, I can simply choose "Save as.." from the "Layer" menu or I can use the "Align Raster" tool from the "Raster" menu. I would have expected that it's possible to choose the resampling method when doing it via "Sav...

I have been trying to define a Gaussian Process from hand by simply writing down the required formulas and apply them to an toy example. Here is what my (noise-free), observed data looks like: x_observed = np.arange(-5, 5, 0.2).reshape(-1, 1) y_observed = np.sin(x_train) fig, ax = plt.subplots(f...

When applying for Uk visa do they see all countries l have been to.

I observe the style of a theorem that uses a shared counter being changed unexpectedly when cleveref is used. I expect all new theorems to have the default style plain as in asmbook, with small caption title font and italic body font. However, when cleveref is used, the fact theorem, which shares...

In this chapter of Brahmanda Purana says:- 24-29a. It was the lord who created all types of sacrifices and the necessary adjuncts thereof. He duly created the sacred fires of Gārhapatya and Āhavanīya and the monthly Śrāddha rite of Anvāhārya. He created the various adjuncts of sacrifice such as ...

Since upgrading to 23.04 there is no longer the option to add a new folder/directory or file under the "three lines" menu in the top right of the Nautilus window. The are only options for a new window or a new tab there, The only way I have found to add a new directory is to use Ctrl + Shift + N....

Part of the Monthly Topic Challenge #10: Möbius Strips, Klein Bottles, and other unusual topological surfaces Warm-up for topological thinking. You are playing Tic-Tac-Toe with the usual 3x3 grid but instead of putting the grid on flat paper it is on a torus. The top is glued to the bottom and th...

I'm currently taking linear algebra and differential equations class simultaneously. However, its not clear to me that why we need 2 linearly independent solutions for 2nd order linear equations. If it was 3rd order, would it be 3 and why? Like is it 2 dimensional when it becomes 2nd order? $$ay'...

Context : We have math class every Thursday. The teacher said, "...в следущий четверг у нас не будет контрольной... ...будет через неделю" To me "через неделю"(1) means in seven days. I asked some friends and they explained that he meant "after 14 days". Then I asked my English teacher (a na...

As in my previous question, I was talking about survival, when the parent star of a planet, Eridanus, froze due to some unknown cause. So the residents of this planet Taurus, the Villagers, have done everything possible to ensure their survival, and for a later time, generate enough heat to warm ...

Why do we need the main function and can't we execute the code without it? Can't we just execute our code outside the main function by making our own function?

Given N integers L1, L2, ... , Ln ,we have a robot that starts at (0,0) moves north on integer grid for L1 steps, then it either continues in its current direction or makes 90 degrees right turn then moves L2 steps and repeats for all Li. Problem: Can the robot return to the origin?

I am using the ESP32 Arduino Framework and I have some GPIO expanders attached via I²C. They work fine and I now want to map some unused pin numbers to them so I can used my custom pin numbers in pinMode, digitalRead and digitalWrite. Luckily, the Arduino core links these functions weakly. extern...

https://en.wikipedia.org/wiki/SpaceX_Super_Heavy The oxygen tank has four chines attached. These protect the various COPVs on board, as well as providing lift during flight. First I've heard of these things. No explanation as to what they are or what they do.

The unit in question asks for 208/230 V ~ 60Hz, 1Ph as the power source. I have a 30 amp circuit breaker that used to be for a water boiler. It's a 30A 2 Pole 120/240V Type Q Breaker The part I'm confused by is the 1 Phase, requirement on the unit, while the breaker is a two pole breaker. Does th...

I was playing around with a thumb drive and I noticed a counter-intuitive trend. The bigger I make the cluster size (allocation unit size in windows, block size in linux), the less capacity gets reported. Which is weird, because basic logic dictates the opposite - bigger clusters should result in...

I am trying to simulate smoke rising from a candle, and was trying to find a way to make a volumetric shader that works on Cycles. I found a tutorial for something similar that works on 2d planes using texture coordinates and a noise texture. Looks like this: But I needed something similar that ...

It might be a very simple question but for some reason I’m a bit confused. Let’s say we enter a long SOFR vs fix interest swap at par. Say 5 year swap with annual coupons (the rfr is daily compounded and paid at each annual reset). The swap rate will be the average of forward rates weighted by th...

I like to use dumbbells for upper body with some regularity to make sure my left arm stays equally strong compared to my right. As everyone is aware, using dumbbells requires using lighter weights; I can't, say, bench press the same weight with dumbbells as I can with a barbell. So my question is...

Consider the data data0, data1: data0 = RandomReal[{0, 1}, {10^4, 3}]; (*Number of columns pairs*) npairs = 12; data1 = RandomReal[{0, 1}, {100, 2*npairs}]; and some function func1 that would use the values of data0, data1: func1[x1_, y1_, x2_, y2_, X0_, Y0_] = Exp[-x1^2 - y1^2 - x2^2 - y2^2]/...

Down below is a conductive bar of length $L$ moving on two conductive rails in a magnetic Field. I have a couple of questions regarding the flow of current in such a system. How does the current flow through the closed circuit if the length of the bar $L$ is larger than the width of the rails $l$...

When I was recently studying biomass-to-electricity (gasification methods, Drax power station...), I was wondering whether the efficiencies of these systems would not benefit from a source of pure oxygen gas: if such a gas were to be used as the oxidans, in stead of ordinary air, the reaction hea...

\begin{tikzpicture} \draw[left color=BlueGreen,right color=BlueGreen] (0,0) rectangle (2,1); \end{tikzpicture} \begin{tikzpicture} \draw[fill=BlueGreen] (0,0) rectangle (2,1); \end{tikzpicture} The result is

Suppose I draw (with replacement) colored balls from bins with probabilities $h_1,\ldots,h_d$ and want to estimate mean time until 2 balls of same colors are drawn. What's the fastest way to estimate this? Adapting JimB's code from this answer is below, wondering if it can be made much faster. Ex...

If you come to this place on Earth then at certain times the closest people to you are in Space! Where are you?

I've sent a Bitcoin transaction using the Bitcoin Core client and later realized the fee was too low (Fee 0.00005814 BTC ~ $1.69 USD) https://www.blockchain.com/explorer/transactions/btc/ab8e9542604ca326a7b1f562feab9db621cc669fce2a6332303ce14714f9e79a So I've added some balance to the same wallet...

What's the 4-word phrase I'm looking for?

I have the following question: Using this equation: $MR = P(1+\frac{1}{ε})$ and the attached graph. How does the vertical distance between the demand curve and MR curve at a given level of output depend on the PeD (ε) at that output level. My Answer: Vertical Distance $= AR - MR = \frac{p•q}{q}...

I am working on a project that involves communication over a 12V DC (2A) power line using a two-wire cable. I would like to transmit data over the same cable and am looking for a simple-to-use IC or solution that can handle communication over 12V DC power lines. Ideally, I am looking for a dedica...

$\pi(x,z) = p(a\ln(x) + b\ln(z)) - w_xx - w_zz$ Question 1: Using the first order conditions, we get: $x = \frac{pa}{w_x}$ $z = \frac{pb}{w_z}$ What do we call these Input demand functions as a function of price i.e. are they just un-compensated demand functions as in consumer theory? . I.e. When...

From the UK Government website: The police arrest procedure If you’re arrested the police must: identify themselves as the police tell you that you’re being arrested tell you what crime they think you’ve committed explain why it’s necessary to arrest you explain to you that you’re not free to l...

I have a hex grid of 10000 cells (100x100). The player can grab a cell next to one of his cells (borders). If the player has formed a ring after placing a cell, I want to get a list of cells that ended up in the encircliment. This is what it looks like before creating the enсircliment The player...

In my magic system, people are capable of forming weapons out of their aura. The density of aura is naturally around 0.1g/cm3, but can be compressed down to 0.5g/cm. This means that aura can at most have a density similar to wood, but can be even stronger than steel. As a result, aura is primaril...

I am trying to be budget friendly and recycle parts for a new project.

We bought our new Chattanooga, TN home in August and it is ~3 years old. The crawlspace has some water penetration on one side of our house. We live on a hill and the water is penetrating on the side of the house that is downhill from our neighbors. The home inspector pointed out the water in the...

I am new to Mathematica and I don't understand how can I plot more numerical functions on the same graph without writing them manually. I don't think that I explain what I do to clearly but I will attach some pictures below in hope of making it easier to understand. xM = 20; Nx = 1024; dx = 2xM...