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In Chapter 9 of Principles of Electrodynamics by Schwartz, which is on waveguides and cavities, there is an analysis of a simple rectangular guide and a calculation of the lowest frequency that can pass through the guide, either $TE_{01}$ or $TE_{10}$ depending on whether $a$ (the $x$ dimension) is greater or less than... |
If standing waves are established in musical instruments like the guitar, then how do we hear the sound because standing waves don't transfer energy from one place to another. At least that's what I have learned.
My guess is that standing waves are established in the string itself but when the string vibrates, it also ... |
I am helping an IB student fit a curve.
We are doing an analysis of F1 in a curve, graphing it velocity vs time.
Any idea what function could I use. In the refference video we used, the guy uses geogebra and fitts the plot in two parts in two different functions. Onw for the first flat part with drop and the second wi... |
Given a self-adjoint operator $A$, I am interested in calculating the generator of the second quantization operator $d\Gamma(A)$.
In particular, I am interested in the case where $A=x\partial_x-\partial_x^2$, which is known as the Ornstein-Uhlenbeck generator. A paper that I am reading suggests that $d\Gamma(A)=A$ in t... |
My statistical mechanics professor stated the Virial Theorem as
\begin{equation}
\langle K \rangle = -\frac12 \sum_{i=1}^N \langle \mathbf{F}_i\cdot \mathbf{r}_i\rangle
\end{equation}
For an ideal gas in a container, the only force applied to the gas particles is by the wall of the container and it applies a force $d\m... |
First, I have a gyro, $\omega$ is its angular velocity
Then, I simple it to
When it moves down, there is
Gravity does work differently for A and B. Therefore, the angular velocity should be changed. But I am not sure it is right since I haven't noticed anything similar in reality.
I'm just a hobbyist in physics, s... |
In Operator Product Expansion (such as explained in Peaking) there appear a quantity for an operator called twist, defined to be $d-s$ where $d$ is the scaling dimension of the operator and $s$ is it's spin. Is there a geometric meaning to that? What exactly is being twisted here?
|
My question is which objects are considered as colorless?
In chemistry we sometimes consider white object as colorless,Many times we use the word colorless for transparent substances like water, glass, etc. But what exactly is colorless in physics?
I thought about this and I think colorless should be referred to the bl... |
Suppose you have a type-2 superconducting cube with a thick superinsulating layer passing through the middle of the cube; visualized below with (grey superconducting mass, violet superinsulator in the middle):
Now suppose you have a flux tube connecting the front face $A$ to the back face $B$ that lies entirely on o... |
When a wire moves in a uniform magnetic field, so do its electrons. If electrons move in a magnetic field, Lorentz's force will act on them. Two sides of the wire will become polarized. We know that Lorenz's force is always perpendicular to velocity so can we say that they accumulate on the sides of the wire doing circ... |
So, I'm trying to write down the passages required to create a wave function (from first to second quantization, to just wave functions).
From the Wikipedia page, basic behaviour, non-dispersive wave section: https://en.wikipedia.org/wiki/Wave_packet
I understand this:
you want a wave packet, so you start from writing... |
I am little confused. Please correct me if I am wrong.
Gamma rays can produce electron and positron pair if they interact with atoms.
In the double slit experiment the final screen where interference pattern is observed is made up of atoms.
Suppose we do a thought experiment where a source of gamma ray is used in doubl... |
I am learning Matsubara Green's functions using Henrik Bruus, Karsten Flensberg, Many-Body Quantum Theory in Condensed Matter Physics, An Introduction (2016). There, the authors calculated the Matsubara polarizability function of non-interacting electrons from Eq. (11.86)
$$
\chi_0(\textbf{q},\tau)= \frac{1}{V} \sum_{\... |
In David Tong's lectures on general relativity the interpretation of the $M$ which appears in Schwarschild metric:
$$ds^2=-\left(1-\frac{2GM}{r}\right)dt^2+\left(1-\frac{2GM}{r}\right)^{-1}dr^2+r^2\sin^2(\theta)d\theta ^2+r^2d\phi^2$$
Is the Komar charge (or Komer mass) with respect to the Killing vector $K_{\mu}=(g_{t... |
I am trying to wrap my head around energy, mass and momentum, especially in the more general scope of special relativity where massless objects moving at the speed of light also have momentum. So I am not particularly interested in how much speeds change with forces or anything. I am just wondering if there is a way to... |
In the book Relativistic quantum mechanics by Paul Strange he has at page 56 the following formula
$$
\begin{aligned}
& ((2 e+1)(2 f+1))^{1 / 2} W(a b c d ; e f) C(a f c ; \alpha, \beta+\delta) \\
& \quad=\sum_\beta C(a b e ; \alpha, \beta) C(e d c ; \alpha+\beta, \delta) C(b d f ; \beta, \delta)
\end{aligned} \tag {2... |
I have been reading a book on Thermal Field theory by Michel Le Bellac During the reading I have come into a seemingly trivial but indeed tricky derivation. On page 26(2.47), we are supposed too prove
$$
(1-exp[-\beta k_0])\delta (k_0+E_n-E_m)=\delta (k_0+E_n-E_m)-\delta (k_0+E_m-E_n)
$$
Does anyone know which property... |
The proof showing that the energy-momentum tensor is symmetric uses the fact that $\partial_\nu T^{\mu\nu}=0$ due to translation symmetry, the definition of the conserved current and that $\partial_\nu J^{\mu\nu\rho}=0$ due to Lorentz symmetry:
\begin{equation}
0=\partial_\nu J^{\mu\nu\rho} = \partial_\nu (T^{\mu\nu}x... |
I came up with a question in a previous physics exam of my professor that I for some reason can't seem to be able to answer, and I'd really appreciate some help in case he gives me the same question when I take the exam.
The question is:
The eigenstates of the energy of a particle in a 3D potential well are $E=b(n_1^2... |
This question is with respect to this paper of Witten (PDF). According to this paper the following path integral holds for a $3D$ manifold $M$
$$\int \mathcal{D}B\mathcal{D}\phi\exp\left(\int_M\operatorname{Tr} \phi D_i B^i+ \frac{k}{4 \pi} \int_M \operatorname{Tr}(B \wedge D B)\right) = \frac{1}{\sqrt{\operatorname{de... |
I am trying to find the 3-gluon vertex rule in QCD by finding the amplitude of a 1-2 gluon scattering process. I want to find the generating functional of the interaction by taking the functional without the interaction and finding the first order correction. I try writing $$ Z[J] = \int DA \: e^{iS[A]+i \int d^{4}x \,... |
I got this question while reading about electrons and protons where electrons having less mass than protons but possess the same amount of electric charge,though negative.
Could you please elaborate the solution in the easiest way possible for I am just a student and have not read much in depth about them.
|
I'm struggling with strong force interaction using particle-properties. In my book they give an example to explain this interaction using a Feynmandiagram of a proton and neutron and say that the proton is at rest. Now in order for the proton to send out a meson it needs energy. Now since the proton has no energy to us... |
We know that if we have a closed loop with an open surface and when we change magnetic flux through this loop there is an emf therefore a current which results in wire creating a magnetic field in a way to oppose our magnetic flux change. If this loop is not closed can I make the flux change so much that there will be ... |
Say a car has to move from Point A to Point B on the surface of the earth. The car starts from rest at Point A at time $t=0s$ reaches point B at time $t=10s$ with a constant velocity of $1000 m/s$. Point B is at a distance of $x=10000m$ from Point A $x=0m$ (which is evident at the rest frame corresponding to the earth)... |
Critical velocity($v$) of a fluid is given by
$v = \frac{Rr}{\rho\eta}$
where,
$R \rightarrow$ Reynolds number
$r \rightarrow$ Radius of tube
$\rho \rightarrow$ Density of fluid
$\eta \rightarrow$ Coefficient of viscosity
$d \rightarrow$ Diameter or characteristic length
But when we look at the formula for Reynold's Nu... |
Let $M$ be a globally hyperbolic spacetime, with metric $g_{\mu\nu}$.
Consider the covariant Klein-Gordon equation
$$(g^{\mu\nu}\nabla_{\mu}\nabla_{\nu}+m^{2})\phi=0$$
Define the following indefinite inner product on the space of its solutions:
$$(f,h):=\int_{\Sigma} d^{3}x \sqrt h n^{\mu} (f^{*}\partial_{\mu}h-h\parti... |
I'm having trouble understanding the interplay between special relativity (more specifically the relativity of simultaneity) and quantum entanglement.
Imagine there are two observers, as shown in the figure with the first having the standard coordinate system and the other having the line spanning CI as its time dimen... |
Suppose $\Phi_\theta$ is a quantum channel whose action can be written for any state $\rho\in \mathcal S(\mathcal H_S)$ in the Stinespring representation as $\Phi_\theta(\rho)= \text{Tr}_E(U_\theta (\rho_S\otimes \tau_E) U_\theta^\dagger)$ for some unitary $U_\theta$ living on the total space $S\otimes E$. Suppose als... |
I know about $1$st, $2$nd or other overtones in the formula of frequency in a one-sided open system (specifically in closed organ pipes) that is
$$ f = \frac{\left( 2 n + 1 \right) v}{4 L} \tag{1} \label{1}$$
where $f$ is the frequency of the wave, $v$ is the speed of sound and $L$ is the length of the organ pipe. Most... |
Here's a gedankenexperiment:
In situation A you run $P$ watts of incandescent bulbs in a closed room for time $t$ (light and heat cannot escape the room). The room starts a temperature $T$ and ends at temperature $T_a$ after time $t$.
In situation B you run $P$ watts of LED bulbs in the same room also for time t. The r... |
I am trying to figure out how a translation or a conformal transformation explicitly look like in embedded space.
Given a CFT in Euclidian (or Minkowski) coordinates $x^\mu$ we can embedded them in $d+2$ dimensional space $$X^{M}=\left(X^{+},X^{-},X^{\mu}\right)=\left(1,x^{2},x^{\mu}\right)$$ or $$X^{M}=\left(X^{-1},X^... |
In a recent paper by Accolierastro's recent video, she goes back to Maxwells seminal paper on electromagnetism, and the section on gravity. In Maxwells paper, he notes the similarity between the lines of force between two poles on a magnet of the same sign, and two masses. By a thought experiment, he considers the ener... |
According to this website explaining the science behind balloons made of latex rubber,
If we repeatedly load and unload (stretch and release) a viscoelastic
material the amount of energy lost in the hysteresis loop will
decrease with each cycle, until an equilibrium is reached.
The force needed to achieve a certain de... |
The original text in my textbook, written in short:
"By Newton's second law,
$$\ddot{\mathbf{x}}_1=-Gm_{2}\frac{\mathbf{x}_1-\mathbf{x}_2}{|\mathbf{x}_1-\mathbf{x}_2|^3}-Gm_{3}\frac{\mathbf{x}_1-\mathbf{x}_3}{|\mathbf{x}_1-\mathbf{x}_3|^3}$$
and analogously for the other two masses. If we make use of the relative-pos... |
Why some laser diodes have angled window? Here is an example
|
If I've got a circle of elastic material that's fixed at the circumference, and I drop a point weight on it, what will the cross section look like?
For example, if I took some material from a balloon, clamped it between two metal sheets that had a circle cut out of them, and then dropped an infinitely small bowling bal... |
I am reading a lot of papers that derive the Hawking temperature solving either the Klein Gordon equation for scalar fields or the Dirac equation for spin $\tfrac12$ particles via tunnelling probability or direct computation of the solution. But I was unable to find a paper that solves the Maxwell equation in a Kerr or... |
I can't find the solution to this problem.
|
Looking at the following circuit:
What would happen right after S is closed and what happens after a while of running?
My idea is that right after closing there will be a short-circuit like behaviour, where there is almost no voltage difference on C. With time the voltage over C increases, which when the capacitor is ... |
I'm learning about the semi-empirical mass formula currently, and in the explanation for the pairing term, the course notes say that it's energetically favorable for nucleons to pair up.
Could someone explain this to me intuitively?
|
Suppose I want to quantize the Hamiltonian of a relativistic particle on space-time $\mathbb{R}^{4}$. Setting $c=1$ for simplicity, the energy of the particle is given by $w(p) = \sqrt{|p|^{2}+m^{2}}$, $p \in \mathbb{R}^{4}$. Suppose I want to proceed as in the nonrelativistic case, where we identify:
$$x_{i} \mapsto \... |
The definition of Echo Time from Radiopaedia:
The echo time (TE) refers to the time between the application of the radiofrequency excitation pulse and the peak of the signal induced in the coil. It is measured in milliseconds. The amount of T2 relaxation is controlled by the TE.
Why do we apply the 180 degree pulse a... |
Imagine you have got a metal rod of length $l$ and the left side of the rod is fixed, and the rod is pointing in the direction of the x-axis of an imagined coordinate system. At distance $d$ from the left side a nonuniform mass is spinning - think of an unbalanced motor. So this unbalanced mass produces a force in the ... |
In the most of textbooks about CFT, the special case of 2d is noticed in which complex coordinates play important role and it reads some results like the conformal transformation of energy-momentum tensor. Is this depends on some algebraic features of 2d case or just because of features of complex analysis like residue... |
Suppose two wave pulses are traveling in opposite directions, but when they superimpose, they completely cancel each other out (destructive interference)
But as soon as they pass each other, they just continue their motion with their original respective amplitude.
Now I'm wondering what happens to the energy of the wav... |
Assume that we have a very tiny spherical or disk-like superconducting material that is subjected to an externally uniform magnetic field. I want to know if the net force that accelerates the superconductor is great or negligible. Is it true if, for instance, the thickness of the disk tends to zero, the net force appro... |
Hubble measured high redshifted galaxies to discover the cosmic expansion. In a hypothetical universe where only one galaxy exists, would there still be observational evidence for the Big Bang theory? In a very distant future when everything except our Milky Way fade away from the horizon, what would be the cosmology d... |
Consider ladder operators $a$ and $a^{\dagger}$ of a quantum harmonic oscillator. Now again say we define an operator $B=B(a,a^{\dagger})$ which is hermitian i.e., $B=B^{\dagger}$. The question is when can we write it in terms of another operator $A$ as,
$$B=A^{\dagger}A?$$
What are the restrictions that one has to imp... |
I am trying to simulate particle collisions in two dimensions (hydrated ions). I have found the formulas I need for the transfer of linear momentum. However, I kind of suspect that angular momentum of individual particles will have to be affected if they collide off-center. This is important in my case because my circl... |
A box is shoved up a plank inclined at an angle $\alpha$ above the horizontal. The plank is covered with ice so that the coefficient of friction is $\mu = Ax$ where $x$ is the distance from the bottom of the plank (in this question the static and kinetic friction are equal). The box's initial speed is $v_0$. I have to ... |
Sound is a longitudinal wave. Loudness of the sound depends upon its amplitude, but I was thinking how to visualize the amplitude of a longitudinal wave. In case of a transverse wave its easy but in case of longitudinal I have difficulty visualizing the amplitude.
Any help will be deeply appreciated.
Thanks!
|
How can I calculate the true mass of an object in a fluid (f.e. air)?
Given:
force measurement (F = 863000 N)
air density (rhoA = 1,29 kg/m^3)
object density (rhoO = 1100 kg/m^3)
g (g = 9,807 m/s^2)
Solution: 88,1 kg.
|
Consider a heavy, symmetric top spinning on a table, initially inclined at some angle from the vertical. Assuming this angle is fixed, it follows that the weight $\textbf W$ and normal force $\textbf F_N$ from the table must act as an external couple on the top, providing the net external torque $\boldsymbol{\tau}^{\te... |
I am trying to study a system whose Hamiltonian, after some transformations can be written as
\begin{equation}
\hat{H} = \hat{N}_1(\omega-i\mu)+\hat{N}_2(\omega +i\mu)+\omega\hat{\mathbb{I}},
\end{equation}
where $[\hat{N}_1,\hat{N}_2] = 0$ and the number operators are defined by $\hat{b}_i^{\dagger}\hat{b}_1$, with t... |
I'm trying to follow along with this paper, which reviews the Bistrizer--MacDonald model of twisted bilayer graphene. I'm particular, I'm struggling to derive their Eq. (100). Starting from the Hamiltonian for both layers [Eq. (99)], the authors claim they can "integrate out states from layer 2" to obtain an effective ... |
A similar question was posted on this site at least ten times, but not quite in this formulation, and with no satisfactory answers, so I give it another try.
Quantum field theory textbooks almost always describe particles as eigenstates of the free Hamiltonian, and their interaction is described in the following way: t... |
I would very much like to understand the motivation behind the correlation between:
$(i\partial\!\!/-eA\!\!/-m)\psi=0$
and
$(i\partial\!\!/+eA\!\!/-m)\psi_c=0$
when dealing with the derivation of the charge conjugation operator.
Why is the first equation only for electrons (says wiki-section: ”charge conjugation for D... |
Is it possible that a star with an initial mass greater than 12$M_\odot$ loses so much mass in the giant phase that it eventually becomes a white dwarf? If it is possible, what constellation or environment would be favourable for this to happen, e.g. a companion of an already present neutron star, the dense population ... |
With a Python program I generated a sinusoid signal and I added to it Gaussian noise.
Now I want to compute the optimal SNR by applying a matched filtering algorithm.
Since the noise is white (at least I think it is, I did not make any assumption on its distribution in frequency), does it make sense to whiten the data?... |
Background: I was always under the impression that when considering the Stern-Gerlach (SG) Experiment, the interpretation of the split of the beams is that the spin $1/2$ particle get measured the first time when it moves into the $B\neq 0 $ area, and is subsequently diverted upwards or downwards, depending on the outc... |
Is the direction of base current always constant in a BJT transistor?
Excluding the transistor breakdown state, is the direction of the base current always the same in the four modes: active mode, cut-off mode, reverse mode, and saturation mode?
However, if the transistor breaks down, does the direction of base current... |
The question is given as follows:
From (6.109) shouldn't the Lagrangian be K(kinetic) - U(potential), but here its K + U? Unless the potential energy is negative, if so I'm struggling to come to terms with it.
|
I'm going through Mahan's "Many Particle Physics", and I'm a bit confused about his reasoning. He introduces the polarisation operator as
$$\textbf{P}=\int\textbf{r}\rho(\textbf{r})d^3r$$
he then says "recall that the time derivative of the polarisation is the particle current"
$$\frac{\partial}{\partial t}\textbf{P}=... |
As I understand, there are 2 types of photons in our (3+1) space with photon helicity $\pm 1$. How many photons exist in another spaces like (2 + 1) or (1 + 1)? Can we apply the same for gravitons?
|
I'm new to the forum, I will try to make my asking as clear as possible.
I'm currently writing a 40-minutes talk on the BRST quantization of the Bosonic string, mostly following Polchinski's Book. The author at page 131 (chapter 4.3) shows the BRST transformation for $X^{\mu}$ and the $b,c$ ghosts. Then reading from $$... |
We had an exam question for calculating the expected value of momentum for a 1D box. Within the integral teacher just wrote zero for $\psi \frac{d\psi}{dx}$. Is this a general thing or just for a stationary particle in a box situation, and if so how?
|
Accelerated charge obeys an energy loss due to radiation. This is one reason why the classical picture of electrons orbiting the nucleus would result in a non-stable atom since the electrons would collapse into the nucleus due to the energy loss. The acceleration of the orbiting charge is the centripetal acceleration i... |
Here is my understanding:
Superposition describes the effect of two waves, of the same type, coinciding at a point, stating that the resultant displacement is equivalent to the vector sum of the individual waves. Any two waves, given that they are the same type, will superpose. However, for two waves that happen to hav... |
As far as I understand, the electric potential is the amount of energy that a third party agent has to spend to move a positive charge from infinite separation to a point. Thus, the electric potential due to a battery cell depends only on the position of the charge with respect to the cell's terminals. So it seems illo... |
I was wondering if there is an experimental set up that would produce something equivalent to a classical electromagnetic field for the weak and strong nuclear forces. I know that the those forces are short range due to the mediators of the weakforce having mass and due to confinement for the strong force, but I was wo... |
In the below screenshot from this paper (link below), why is the 2nd Maxwell equation ($\nabla \cdot H = 0$) not automatically satisfied when the 4th Maxwell equation is satisfied? I don't understand this, since I thought div of any curl is 0, so $\nabla \cdot H = 0$ should be satisfied. This logic is applied to explai... |
I'm reasonably familiar with special relativity and its effect such as time desynchronization, but I'm having trouble understanding how these effects come into play when we also consider the time for light to reach us. I'll describe my problem using this image:
We will be observing 2 objects (the red vertical lines). ... |
In rotational kinematics, there seem to be two common characterizations of a rigid body:
A rigid body is any collection of particles with position vectors $\textbf x_1,\textbf x_2,...$ such that the distance $|\textbf x_i-\textbf x_j|$ between any pair of particles $i,j\space $ is conserved, i.e. $\frac{d}{dt}|\textbf... |
I've recently been watching this lecture series in Condensed Matter physics. We have covered second quantization, used it to obtain the tight-binding model and then studied the band structure of various different lattices using these techniques. The last few classes I've watched were on how to obtain experimental obser... |
I have this homework on an analysis of a constrained Hamiltonian system and I need some help with the following problem. The system is described using Darboux coordinates and a specific Hamiltonian:
Consider a Hamiltonian system with the following Darboux coordinates: $\{P_N, N; P_\mu, X^\mu\}$ where $\mu : 0, 1, 2$. I... |
We often say that the benefit of relativistic index notation is that we can write down equations of motion that are automatically Lorentz covariant. However, I'm starting to feel that there are many Lorentz covariant equations of motion that we can write down that are nevertheless "Lorentz inconsistent" in some sense. ... |
Consider two flat infinitely wide and high rectangular magnets located a distance $L$ from each other in what is otherwise a vacuum. Visualized below:
If the magnets are aligned properly there will be an attractive force between them. One interpretation of this attractive force is that there is a sea of virtual photon... |
Suppose you have a rubber band, and a point is marked on the rubber band at the 1/3 point. If you now apply force to the two ends of the rubber band to stretch it, will the point maintain its 1/3 position on the new rubber band? That is, is the marked point still the 1/3 point of the rubber band? If not, what is its po... |
Working on a self watering planter and am having trouble calculating the way this water would spread between connected vessels. The top vessel will connect to the other vessels with small aquarium tubing, what would the calculations I need to make be in order to get the water spreading evenly? I'm guessing I would nee... |
What is the Lorentz transformation of the (scalar) electric current, $I$ ? I got two answers that are not consistent: Consider a lab frame where the charges are moving with a velocity $\vec{\beta}_q$, and consider another (primed) frame that moves with velocity $\vec{\beta}$ (all velocities are relative to the lab fram... |
Please correct me if I am wrong.
In a double slit experiment, in order to measure wavelength,there seems to be a minimum size of slit (e.g hydrogen atom) and on galactic scale there seems to be an interplanetary distances as a limit to the size of the slit.
Waves can be mechanical , quantum mechanical or electromagneti... |
I am working on modeling the effects of an electrode in a microchannel flow. I am a little confused about how to model this.
I have two electrodes on the boundary. Do I add the electric field effects in the velocity boundary conditions or in the momentum equation as an external force term. I have seen both cases in the... |
I am working with a spherical capacitor consisting of an inner radius R1 and an outer radius R2. The region between the plates of the capacitor is filled with four dielectric materials, each shaped like a spherical wedge with an angle of π/2. These materials, occupying equal quadrants, extend from the inner radius R1 t... |
I was browsing PhysicsForums and I came across an interesting fluids question. I understood the method suggested to solve it, but I wanted to see if I could solve it through integral calculus.
[Question source - original method.]
A tube of uniform cross-section $a$ is bent to form a three-quarter circular arc of radiu... |
Consider a quantum field theory with the following action
$$S[\phi] = \int d^dx \left(-\frac{1}{2}\phi\Box\phi -\frac{m^2}{2}\phi^2 +m^d\ln\frac{\phi}{m^{(d-2)/2}}\right)\\=m^d \int d^dx \left(-\frac{1}{2}\tilde{\phi}\bar{\Box}\tilde{\phi} -\frac{1}{2}\tilde{\phi}^2 +\ln\tilde{\phi}\right)$$
where $\tilde{\phi} =\phi/m... |
According to this article, for a disk-like superconductor and a magnet, if the radius of the superconductor tends to zero or the radius of the magnet tends to infinity, it seems that the levitation force approaches zero. (Cf. figures 4 and 5) However, I cannot trust my claim since the levitation forces in the article a... |
I am trying to understand the paper "Anti De Sitter Space And Holography" by E. Witten (cf. https://arxiv.org/abs/hep-th/9802150).
One of the first point it makes is that "Minkowski space appears as the boundary of AdS space" as a compactification.
In order to accomplish this he presents the relation
$$uv-\sum_{i,j} \e... |
Since heat is molecular vibrations, vibrations have frequencies, and applying energy to a system at its vibration frequency is an effective way to rapidly increased the amplitude of its vibrations, is it possible to heat matter using discrete, rapid bursts of energy at the right frequency?
Is this what Microwave ovens ... |
The question I want to ask is the following:
There are $N$ Majorana fermion modes: $\gamma_1, \gamma_2, \dots, \gamma_N$, and they satisfy the anti-commutation relation:
$\{ \gamma_i, \gamma_j \} = 2\delta_{i,j}$.
There can be some orthogonal transformation to these Majoranas:
\begin{equation}
\gamma_k \rightarrow \sum... |
In my point of understanding, interference is produced when waves from two sources of light (may be coherent or non-coherent) overlap resulting in consecutive bright and dark fringes on a screen. But, what it means to have interference in a single slit?
Consider this Phet simulation of single slit diffraction.
I could... |
how can i check that following 4-current for a single charged particle
$$j^{\mu}(x)=qc\int d\tau u^{\mu}(\tau)\delta^{4}(x-r(\tau))$$
satisfies continuity equation $$\partial_\mu j^\mu = 0.$$
|
In a Group IV semiconductor (like Si, Ge), one atom makes 4 covalent bonds with its neighboring atoms. They create in this way the so-called a tetrahedral bond (that of the diamond structure). Each 2 atoms are bound via 2 electrons with opposite spins. These bonding electrons exist in the valence band, they are localiz... |
What is intrinsic parity? It seems that it is a concept only for relativistic quantum physics. Why is it not relevant for non-relativistic quantum mechanics?
|
I understand that an object becomes postively charged when it looses electrons.
I was curious, at 5:45 of this video Electronics at Work - 1943 (https://www.youtube.com/watch?v=hwutHPYGgfU), how does the particles loose their electrons and acquire their positive charge by passing through a parallel 1300V plate?
|
re mathematician so im so lost... Any help will be very appreciated!
|
The solar core has a temperature of 15 million K, but the visible color temperature is only between 1000 K and 10000 K. Also, the plasma is very dense at the core, so it won't be able to travel there.
If I had a magical camera that I could put anywhere in the sun to measure photons, in how many percent of the sun's vol... |
I have been told that energy and mass are the same. What puzzles me is why don't we use the same units of measure for both if they are the same? The unit of mass is kg and the unit of energy is the joule or kg(m/s)² Why the different units of measurement if they are the same thing?
|
I intend to use a cantilever beam to calibrate a strain gauge, in a setup similar to the picture.
My idea is to introduce a small known vertical displacement $\delta$ on one side of the cantilever through a micrometric screw and to compute the strain in the upper surface of the cantilever to compare it with the strain... |
My imagination about EM waves is that they sum together when they meet (that superposition principle) and i struggle to understand the concept how is it possible that change in frequency allows us to read just the signal we are interested in (differentiate between two signals if they have different frequencies).
If i h... |
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