Computation Definition and 250 Threads

Hello I'm trying to model a controls system. The issue I'm having is that the equation of motion and taking the Laplace transform and obtaining the transfer function is computationally difficult. I'm new to this so I don't know which software tools to use. I've heard about Matlab and python. I...

A lot has changed since the following threads were active. Computation in nuclear engineering https://www.physicsforums.com/threads/computation-in-nuclear-engineering.282715/ Using HELIOS Code for Preparing Macroscopic XS in PARCS...

Hello, I need to solve the commutator relations above. I found the equation above for the last one, but I am not sure, if something similar applys to the first one. I am a little bit confused, because I know there has to be a trick and you don't solve it like other commutator. Thanks for your help!

In interpretations of quantum mechanics there are two types of physicists: those who care about ontology and those who don't. The ontologists, or realists, want to know what is the world made of. The non-realists, on the other hand, think that this question is not relevant to physics. Usually...

Hello everyone - this is my first post on the forum and this would be for a real world application. I have no mechanical engineering experience. We plan to build a cubical aluminium (6082 grade) pressure vessel. The total external dimensions are 540mm x 400mm x 75mm. The aluminium wall...

Hi, I am looking for an app that converts a checklist to text. The advantage of this app is to save time in writing professional reports. For example, suppose a professional uses a list of 10 possible variables to examine a case but finds only 4 variables match a pre-set quality criteria. In...

In first part,since every block of 4 consecutive symbol contain at least 2 a's The answer in notes is given (aa(a+b)(a+b)+a(a+b)a(a+b)+a(a+b)(a+b)a+(a+b)aa(a+b)+(a+b)a(a+b)a+(a+b)(a+b)aa)+ But this wont be true since if we choose aabbbbaa which is possible according to the above regular...

In this thread I attempt to find a closed form solution to the gradient descent problem for a single sigmoid neuron using basic calculus. If you would like to give pointers feel free, if you see me make a mistake please let me know! Thank you!

I watched a video on the topic by Sabine Hossenfelder. Now it is said by many that this proves the photon "knows" something in advance because a certain state of a certain beam splitter can be probed in theory without the photon ever encountering that beam splitter because it took another path...

Quantum gates must be reversible. The usual justification for this is that in QM the time evolution of a system is a unitary operator which, by linear algebra, is reversible (invertible). But I am trying to get a better intuition of this, so I came up with the following explanation: In order to...

Summary:: Looking for articles/books to prepare myself for the course: Quantum computation with superconducting qubits Hello everyone. I am about to take a course in Quantum computation with superconducting qubits and I am searching for material to prepare it. I took a first course on that...

Hello all, I am hoping to get some feedback on the manner in which I performed computations towards solving the following problem. There are a couple specific points which I am not confident of: 1. Did I properly account for the manifold structure in my computation of the nonzero components...

I'm not sure if this is the correct forum to post this question, or should I post it in a math forum. But I was looking at some code when I found a 'strange' implementation to compute the derivative of a function, and I wanted to know if any of you has an idea of why such an implementation is...

Attempt at solution-: Now this dfa will also accept abba which in my inituition it should not accept. But it does accept it. What is going here? Please guide

On page 344 of "A First Course in GR" he writes the following: When I do the integration I get the following: ##\int_0^{\chi^2}d\chi^2= \int_0^{r^2}\frac{dr^2}{1-r^2}= \chi^2 = -\ln (1-r^2)##, after I invert the last relation I get: ##r=\sqrt{1-\exp(-\chi^2)}##, where did I go wrong in my...

I am starting my Master's Degree in Nuclear and Particle Physics, should i invest in taking a course in Parallel Computation? I know the role that Parallel Computation has in particle physics, but is there any use in a particle physicst learning about parallel computation, or could it be...

Dear Community, I am having a question. I have developed a simple code to perform iteration power algorithm and find the keff value of a system. However, it is not still totally clear in my mind if I have to normalize all my scores by the eigenvalue, i.e. multiply by the keff (fluxes, power...

I have a 2-dimensionsal smooth function ##f(x,y,t)##. There may be multiple traveling waves across the domain. None of them are precisely traveling waves (the shape of the wave changes as it travels). Here is how one of these waves would look in 1-dimension: I want to find the speed of these...

Hi. For some background, I am running molecular dynamics simulations of silica fracture in LAMMPS. Each point represents the location of a broken bond. I would like to find regions where many bonds are breaking, which I speculate would be locations of crack formation. These computations are...

Hi bear with me I have a conundrum I want to ask you. If data traveled many times the speed of light could the results of decrypted cypher message be computed quicker than any system we currently have? For instance if we sent a burst of data at many times the speed of light across the solar...

Hi, The Homestake gold mine near Lead,South Dakota is excavated to 8000 feet below the surface. Lead is nearly a mile high; the bottom of the Homestake is about 900 m below sea level. Nearby custer peak is about 2100 m above sea level. What is the ratio of barometric pressure on the top of the...

Hello everyone! I was studying chaotic systems and therefore made some computer simulations in python. I simulated the driven damped anhatmonic oscillator. The problem I am facing is with solving the differential equation for t=0s-200s. I used numpy.linspace(0,200,timesteps) for generate a time...

Hello, I didn't understand the geometry of molecules in which central atom has no lone pairs of electrons. for example, in $CH_4, NH_4^+$ molecular shape is tetrahedral and bond angle is $109.5^\circ$. How is that bond angle computed? $CH_4$ stands for liquid methane and $NH_4^+$ is a...

Hello everyone. I 'd like to learn how to calculate the spectrum for elements. Which books are recommended?

photoelectric effect is now explained in quantum idea. Why the classical model fails? Are there articles computing it in detail using classical model?

Consider an equation, $$\tilde{x_0} = \ln(X+ i\delta),$$ where X may be positive or negative and ##0< \delta \ll 1##. Now, if ##X>0## this evaluates to ##\ln(X)## in some limiting prescription for ##\delta \rightarrow 0## while if ##X<0##, we get ##\ln(-X) + i \pi. ## Now, consider...

i want to known whether virtual particle exist or not , and does exchange of particle really happen in interaction.

Hi guys, I am currently having some difficulties with this quantum state. I don't entirely understand what that letter 'i' means, where it comes from and why it appears in brackets [1, i]. Shouldn't there be a '0' instead? I am an absolute beginner in quantum computation. I've been following a...

This is in python: #ELECTRIC POTENTIAL from mpl_toolkits.mplot3d import Axes3D from matplotlib import cm import numpy as np import matplotlib.pyplot as plt dx = 0.1 dy = 0.1 xrange=np.arange(-1,1,dx) yrange=np.arange(-1,1,dy) X,Y = np.meshgrid(xrange, yrange) max_dV = 10e-5 blockRadius = 3...

I'm in a Physics BSc programme and I would like to delve into quantum computation and quantum information. There are two master's degree in Europe that I find interesting in particular: Quantum Engineering MSc at ETH Zurich and Applied Physics MSc at TU Delft (track in Quantum Devices and...

In 2000 the company had 300 customers. In 2015, this company already had 1200 customers. How many customers did the company have in 2008 if we know that the number of customers growing is linear?Just want to make sure, is 780 the correct answer?

I am searching for the appropriate methodology/equation(s) to step beyond Boyle's Law to account for the phase change and solve this problem. All suggestions/guidance is greatly appreciated! Bruce

This may be a somewhat disorderly, unplanned out question, but nonetheless, I don’t know whether or not there exist any suitable academic advising websites that would be suitable for posting such. Would it be worthwhile investing time into learning theory of computation and automata via Neso...

Hi, I'm currently learning QC with Nielsen's QCQI. I've written a program in Matlab following the factoring algorithm in page 233 and 235. I run the program for factoring 15, 18, and 25. I got the proper results several times, but I also got error reports sometime, especially when factoring 18...

One thing that confuses me is the physical speed and sound speed. The lattice sound speed cs=1/sqrt{3} corresponds to the physical sound speed for isothermal flow (sqt{RT}). Why isn't the physical speed (e.g. inlet speed up of lid cavity) converted and use accoringly? $$c_p=\sqrt{RT}≈330m/s...

Summary: A book about problems of quantum computation? I remember that there is a book containing many problems of quantum computation, but I can't find the page or post now. I have hard time learning quantum computation. Thus, I want to try to solve problems in order to get a solid...

Hi. After learning quantum computation for months, it fascinates me. Quantum computation expands my view about computational methods. I believe that many future achievements can be obtained from quantum computing, especially the combination of AI and quantum computation. Meanwhile, I think...

I've read that ##\left | \psi \right > =cos \frac \theta 2 \left | 0 \right > + e^{i \phi} sin \frac \theta 2 \left | 1 \right >##, and the corresponding point in the Bloch sphere is as the fig below shows. I think ##\left | 0 \right >## and ##\left | 1 \right >## are orthonormal vectors...

Hello, again. My current interest is quantum computation. I've finished Griffiths' QM for the first time. Because it only takes me a month studying the book, I may have study it superficial, so I plan to study it again and complete all the problems after each chapter. Then is this book...

According to this article, written by D-Wave's CEO, the advent of quantum computers will "change the way the world uses energy". However, on a first reading, it sounds like an advertorial that pushes nonsense. I'm no energy scientist (unless you put high energy physics in that category for some...

I've seen much about jerk, and how it's generally nearly instantaneous, and for general acceleration, that's fine. However, if I lift at a constant acceleration upward slightly stronger than gravity is pulling me downward, the gravitation pull of the Earth will offset part of my force, so that...

Find dfa's for the following language on $\sum$={a,b}; c) L={w:${n}_{a}$(w) mod3 < 1;

In most treatments of the mass renormalisation in dim reg, I see sources find the mass counter term by extracting the coefficient of e.g the ##m^2## term accompanied by a pole in epsilon. I know the mass counter term is found by placing an X on diagrams where there is usually a self energy...

Hello to everyone that's reading this. :) 1. Homework Statement (Theory of Computation) proof problem about proving that L = L(A) by proving that L ⊆ L(A) and that L(A) ⊆ L: https://www.docdroid.net/du7lLvh/theproblemanditssolution.pdf Homework Equations • Mutual simple induction • Formal...

Homework Statement Consider the real-vector space of polynomials (i.e. real coefficients) ##f(x)## of at most degree ##3##, let's call that space ##X##. And consider the real-vector space of polynomials (i.e. real coefficients) of at most degree ##2##, call that ##Y##. And consider the linear...

I am trying to improve my understanding of Lie groups and the operations of left multiplication and pushforward. I have been looking at these notes: https://math.stackexchange.com/questions/2527648/left-invariant-vector-fields-example...

Hi PF! I'm trying to compute $$ \frac{1}{\sqrt g}\frac{\partial}{\partial u^\mu}\left( \sqrt g g^{\mu v} \frac{\partial \eta(s,\phi))}{\partial u^v} \right) $$ where I found $$ \sqrt g = \csc^2\alpha \sin s\\ g = \begin{bmatrix} \csc^2\alpha &0\\ 0 & \csc^2\alpha\sin^2 s \end{bmatrix}...

To illustrate my problem say I have the following table: Option, x , y A , 25 , 30 B , 5 , 12 C , 3 , 9 D, 12, 13 I want to create a graph of every possible combination in the set where the x values are added and the y values are added. For example say it was...

Hello! Recently I was going through some old exams and upon encountering this problem (which seemed pretty easy) I got stuck. Exams at my university are composed of individual tasks, each having three subquestions with four plausible answers respectively. Solution sheet gives results only, so...

Hi PF! I am using the following code in Mathematica mat = {{1, Cos[2], Cos[4], Sin[2], Sin[4}, {1, 1, 1, 0, 0}}; Li[x_] := Transpose[ NullSpace[ mat].{{1}, {Cos[x}, {Cos[ 2 x]}, {Sin[x]}, {Sin[2 x]}}]; Li1[x_] := Li[x].{{1}, {0}, {0}}; f[x_] :=...