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I am trying to understand the degres of freedom for gases.
Air has 5 degrees of freedom at room temperature but why does Argon, $Ar$ have 3 degrees of freedom while $O_2$ has 5 at the same temperature (at 1 atm) and 3 at 100K?
I looked up the boiling temperature for oxygen and it is $-183^oC=90K$ and it is well below r... |
In the following image, you are asked to create an equation that represents the position of the moving part as the magnet pulls the metal object.
If the force acting on the system is constant and the positive x direction is going towards the direction of spring, I used the following equation to represent the position ... |
I want to prove that the particle number operator $$N = \sum_i a^\dagger_i a_i $$ commutes with a general product of creation / annihilation operators, e.g., $$(a^\dagger_1)^2 (a^\dagger_2) (a_1)^7 (a^\dagger_3)^2 ...$$ as long as the number of creation operators is equal to the number of annihilation operators.
So I p... |
I know this is a silly question, the definition of the value is the formula for the value itself but I have tried putting the constants in and I am not getting the same answer. What am I doing wrong?
|
Basic question:
Why does temperature remain constant during a state change?
The general answer I find in most places is that during a state change, the energy supplied is used to change the potential energy of the molecules in the substance and not the kinetic energy.
On Quora, one user writes "When the solid has bee... |
I am self-studying Griffiths's Introduction to Electrodynamics (4th edition) and all has been smooth sailing except for section 4.2.3 in which Griffiths argues for why we can compute (at least at the elementary level of classical electrodynamics that I am currently studying) the field due to a polarized dielectric chun... |
Why time is not like other dimensions is a real amount? In relativity time axis is $i*c*t$, where $i$ is the imaginary unit and $c$ is light speed in free space. Did science or philosophy reached to any answer of this weird property of time? And does this property have anything to do with the uni direction through time... |
In one of my lab courses, we are using an interferometer. I can understand how the interference works when it comes to monochromatic light, but for white light, I am unable to picture how the interference should look and why.
My main problem is with different phases of the wavelengths. In the case of monochromatic ligh... |
Suppose I am standing on some sort of platform close to the surface of earth.
This platform begins to accelerate very slowly horizontally with respect to my reference frame such that I don't notice the shift in my inertia.
As the platform moves, I of course move with it because of my weight establishing friction betwee... |
I was reading this post. It says that the electron produces a magnetic field due to its internal magnetic dipole which is given by
$$
{\boldsymbol \mu}= \frac{eg}{2m} {\bf S}
$$
In Purcell's book, he gives an explanation of how the magnetic field arises due to wrong frames. Although this seems to be disputed here.
But... |
$$\frac{d \rho\ }{\rho} = -\alpha\ dT + \kappa\ dP $$
Where:
$\rho\ $is density
$\alpha\ $ is the coefficient of thermal expansion
$\kappa\ $ is the coefficient of compressibility
$T$ is temperature
$P$ is pressure
|
Why are fringe diameters large near zero path difference, and why are the colours only visible near zero path difference?
|
When Canonically Quantising the Klein-Gordon Field you usually start with the Klein-Gordon Equation, from which you can guess a corresponding Lagrangian Density. Then utilising this information along with assumed Commutation relations for the field and it’s conjugate momentum you “Quantise” the field. From what I’ve re... |
Can an alpha particle (or any charged particle) can penetrate through nucleus of gold (or any other) atom ?
Today I was watching a lecture on the "Estimation of Size of Nucleus" which was a subtopic of Rutherford's Atomic Model, where a respected teacher elaborated the calculations made by Rutherford to estimate the si... |
I am curious to know what problem did Sommerfield solve in his atomic model and how does his atomic model solve it? Most books say it solved the problem of splitting of lines but what excatly does it mean? what is splitting of lines problem? Please explain me. A simple explanation about Sommerfield's atomic model in yo... |
Now that gravitational waves are confirmed. Not to mention the other numerous experimental verifications.
Why do we still need an elusive graviton? Isn't there not enough evidence that the space-time curvature is a thing?
Please don't mind if the question is stupid, I'm not a physicist, it's a hobby of a sort.
|
A single photon's energy is given by $E=hf$. This is also generalized to massive particles as $\lambda = \frac{h}{p}$ or $E = \sqrt{m_0^2c^4 + (hc/\lambda)^2}$ (they're equivalent for photons).
Having already measured gravitational wave frequencies, should we expect this to apply to quantizing gravitational waves? Or i... |
David Tong's definition of active transformation is clear. Under active transformation coordinates (basis vectors) are not changed but rather the field is.
I denote the old and new fields as $\phi$ and $\phi'$. So by active transformation
$\phi'(x) = \phi (\lambda^{-1} x) $.
Notice that I have put the prime on the fiel... |
The magnetic energy per unit volume for an inductor can be derived from the formula:
$U=\frac{1}{2}L{I}^{2}$
But how to derive formula for energy per unit volume for a (long) wire. Since there is no inductance for the wire, I don't know to derive it.
|
There is no position vector in general relativity. I was wondering whether a quantity like
$$k_\mu x^\mu$$
where $k_\mu$ are covariant vector components is to be treated like a scalar i.e. invariant under coordinate transformations?
A came across that problem, studying gravitational waves. In one coordinate system $x$ ... |
Recently I have been studying about the pendulum and had an investigation of the double weighted pendulum of the metronome. Referring to the diagram in the following site, I have some parts that I don't understand and could you explain them?
How does a metronome allow such a wide range of tempos in such a short dista... |
I am a bit confused on the way Landau derives the Lagrangian of the free particle in SR (L. Landau, E. Lifshitz - The Classical Theory of Fields) and his conclusions about the equivalence between mass and energy.
He claims that there exists an integral that assumes its minimum value on the actual trajectory of the part... |
Do quantum fields in QFT interact with each other constantly and continuously, or only from time to time?
|
After all, they are a (self-sustaining) perturbation of the same field, like sound waves or water waves are "energy flow" (except these ones experience dissipation).
And how can our eyes be so clever to perfectly sort and recognize objects if the air is "polluted" with all kinds of photons bouncing all around?
|
On page 581 of Ashcroft and Mermin, Solid State Physics:
Acceptor Level In contrast to a donor level, an acceptor level, when viewed as an
electronic level, can be singly or doubly occupied, but not empty. This is easily seen
from the hole point of view. An acceptor impurity can be regarded as a fixed, negatively
char... |
If I have that $$v(T)=\int_0^T\frac{F_x}{m}=\frac{F_0 T}{2m}.$$
Then shouldn't $$x(T)=\int_0^T\frac{F_0 T}{2m}=\frac{F_0 T}{2m}\int_0^T1=\frac{F_0 T^2}{2m},$$
i.e integrate $a$ to get $v$, integrate $v$ to get $x$. But the correct answer for $x(T)$ is given as $\frac{F_0 T^2}{3m}.$ Have I operated with false assumption... |
In the picture below, in a), a body K1 is pivotably attached to a bearing. My question is about the torque that results from a force exerted onto a surface of the body K1.
A first force F1 applied orthogonally onto the surface should result in a torque M1 in clockwise direction.
Is it correct that a second force, F2, a... |
How is it possible that the every particle in the universe agrees on the laws of physics?
What enforces those laws? Might the laws change slightly across the universe in the same way the cosmic microwave background radiation (CMBR) does?
|
According to the principles of identical particles, the wavefunction of a collection of fermions must be antisymmetric and such a state is entangled. Doesn't this mean that any given electron in the universe (which is a giant system) is entangled with every other electron in the Universe? Why not?
|
Given a coordinate system, where the $x$- and $y$-axes are on the horizontal plane and the $z$-axis is vertical.
Assume I launch a ball along the $y$-axis with backspin and sidespin. Immediately after being launched, the backspin is around the $x$-axis and sidespin is around the $z$-axis. As the ball flies through the... |
So, I'm a little confused on how this would actually work.
For a Homework question, I needed to analyze a short little simulation where I collect Data to prepare a velocity-time plot and position-time plot. I'm a little confused about how what I do. For the velocity-time plot part
The Data I collected was:
Seconds (s) ... |
Dear fellow physics lovers,
Given 3 objects A, B and C, travelling with relative velocities such that
$\vec{v_{AB}}$ = Velocity of Object A with respect to Object B
$\vec{v_{BC}}$ = Velocity of Object B with respect to Object C
We know that for Non Relativistic Speeds (where v<<c) we can calculate Velocity of Object A ... |
Let's say I was launching a model rocket at a 45 degree angle to find the distance between the rocket's landing site and the rocket's launching site, but before launch I wanted to try and calculate where the rocket would land. How would I go about doing this?
|
Consider an entangled pair described by the wavefunction
$$\lvert1,0\rangle = \frac{1}{\sqrt{2}}(\lvert\uparrow_1\downarrow_2\rangle-\lvert\downarrow_1\uparrow_2\rangle)$$ in in the $S_z$-basis. If the first measurement finds Alice's particle to be in the $\lvert\uparrow\rangle$ state, then Bob's particle is found to b... |
Given the phase space evolution of a system, $x(t)$ and $p(t)$, is there any way of getting the hamiltonian to make a later study of the system under the hamiltonian formalism?
My first thought was to take the time derivatives of the phase space coordinates, $\dot{x}(t)$ and $\dot{p}(t)$, and then try to integrate the... |
It is very common to hear cosmologists talking about what happened some time after the Big Bang.
Here is a good example of chronology: https://en.wikipedia.org/wiki/Chronology_of_the_universe
The most common thing is that they say that the universe was sparse and cold enough 380.000 years after the Big Bang for light ... |
In one of my thermodynamics lectures, I came across something of the from
$S = \int \frac{dU+pdV}{T}$ which I know to be a line integral in differential form. I saw that in a problem this was simplified to $S= \int\frac{dU}{T}+\int\frac{pdV}{T}$. I was under the impression that we cannot simply separate the terms like ... |
In the A&M, the conductivity tensor $\sigma$ can be expressed as
$$
\sigma = \sum_n e² \int \frac{dk}{4 \pi³ \hbar} \tau_n(\epsilon_n(k)) v_n(k) v_n(k) \left( -\frac{\partial f} {\partial \epsilon} \right) \tag{13.25}
$$
where $\tau_n(\epsilon_n(k))$ is the relaxation time for the band $n$, $v_n(k)$ is the mean velocit... |
I had a quick check in the help page (there wasn't much info on these
types of questions). It looks to be allowed
I know this doesn't technically constitute as proof (since it assumes other equations are correct though I minimised this as far as possible). I just wanted a logical reasoning for the ideal gas equation:... |
How do the spin, lifespan, radiation, gravity, and relativistic effects (time dilation in relation to proximity) change as you start from minimal mass to more massive black holes (not limited to the mass realistically possible, but limited by how far our equations can go before breaking (since I want to avoid hypotheti... |
A Newtonian fluid of constant density $\rho$ is in a vertical cylinder of radius R with the cylinder
rotating about its axis at angular velocity $\omega$. Find the shape of the free surface at steady state.Consider the cylindrical coordinate system for analysis. Consider the pressure (P) to be a function of two coordi... |
Consider a system executing a finite motion, described by its hamiltonian $H$ and characterized by some parameter $\lambda(t)$ being varied over time.
Reading Landau & Lifshitz (Mechanics, paragraph 49), I am having trouble understanding what does it mean for $T\frac{d\lambda}{dt}$ to be much smaller than $\lambda$ (wh... |
Here on this slide on page 54:
Only the short-circuit current ($J_{SC}$) is given with respect to area, whereas the voltage stands without relation to area. One could calculate it, because the area is given.
I just wondered, since I never heard about a open-circuit voltage density, but a lot about short-circuit curren... |
We know that the Lagrangian of a relativistic particle is as follows: $$L = -mc^2\sqrt{1-(v/c)^2},$$ with the action being the integral of this Lagrangian with respect to time in the reference frame of the particle. My question is, does the action rely on a particular choice of the inertial frame?
|
Studying supersymmetry, I came across the introduction of the idea of SUSY field variations involving spinor parameters $\epsilon_{\alpha}$ under which actions must be invariant. This spinor parameter transforms a scalar field into a fermion via:
$$\delta(\epsilon) \phi(x) = \bar{\epsilon} \psi(x)$$
So I'm struggling w... |
Dental drills have always been cutting edge technology when it comes to high rotational speeds. According to Wikipedia modern drills reach more than 180 000 rotations per minute (rpm), which is 3000 rotations per second! For comparison, household drills operate at around 1000 rpm. Obviously a dental drill operates much... |
Assume to have a spherical nanoparticle of a metal whose Fermi surface in the crystal is a sphere (I think those are the metals having very symmetric crystals). Would then the Fermi surface be spherical?
|
What are the distinctions between Non-extended SUSY and Extended SUSY?
(Is that just a non-extended SUSY has $\mathcal{N}=1$ while the extended SUSY has $\mathcal{N}>1$ ? Then there is no conceptual upgrade?)
2.
If we start from a non-extended SUSY, how to obtain an extended SUSY?
If we start from an extended SUSY... |
It has been pointed out in a previous post that the convention used for the gauge covariant derivative tends to be different in nearly every textbook. As was pointed out in this excellent answer, these differences fundamentally boil down to the choice of the metric signature and the sign convention for the elementary c... |
I came across a problem whose statement is as follows:
An electron moves in the potential well $P (x) = -\delta$ for $- a <x <0$ and $P (x) = \delta$ for $0 <x <a$ (Fig. 13.7). Use first-order perturbation theory to compute the first four energy levels. Set up the expression for the first-order expansion coefficients f... |
I have a coaxial cylindrical capacitor as shown, with inner radius a and outer radius b.
The potential difference across both cylinders is V. I need the magnetic field everywhere when the inner cylinder rotates with constant angular speed $\omega$. I'm kinda lost here and I don't know if what I'm doing makes sense.
I ... |
I am a bit confused about neutrinos in the standard model. The vertex of the weak interaction charged current, implies that any neutrino interacting through the charged current must be left handed. However the neutral current allows coupling to the right handed particles, too (and we see that in the interactions with c... |
I saw this excerpt from the wikipedia article on EPR paradox
They postulate that these elements of reality are, in modern terminology, local, in the sense that each belongs to a certain point in spacetime. Each element may, again in modern terminology, only be influenced by events which are located in the backward lig... |
I don't know anymore if I read it somewhere or (mis)read it between the lines in a paper... so I would like to know if there is such a relationship between the open-circuit voltage $V_{OC}$ and the short-circuit current $I_{SC}$ ?
|
Long ago in high school I saw a short film in which as I recall the apparatus was just a spinning paper plate (with holes along its edge) with a light source -- I don't recall a spinning mirror or a half-silvered mirror -- and the entire experiment could be done in a classroom. The basic idea that even though the speed... |
I read that in the rest frame of a positive muon, decay positrons are preferentially emitted in the direction of the muon spin. Why is that the case?
The decay is $\mu^+\to e^+\nu_e\bar{\nu_\mu}$. Assuming that the positron is emitted at almost the speed of light, it will be a right-handed particle. The 2 neutrinos ar... |
Is the Marx bank still the fastest pulse forming network for generating high magnetic fields at large scale, or is there another design that outperforms it?
|
According to the no-hair theorem a black hole can be completely characterized by three parameters: mass, electric charge, and angular momentum. Can any of these parameters be determined by an observer who is inside the event horizon of the black hole?
|
Let $K$ be a bounded piece of conductor, embedded in an isotropic, homogeneous, uniform dielectric of permittivity $\epsilon$.
Let $ \vec r$ be a point in the exterior of the conductor. Let $\rho_f$ be the free charge density, where all the free charge is on $K$.
Can I say that $$
\vec D(r) = \frac{1} {4 \pi \epsilon }... |
So on page 93 of Peskin and Schroder:
How would this work if I add an extra path, would it be $4!=24$ or $4\cdot2=8$?
Is it different permutation of the 4 path? Or is it 4 different way to reach $y$ from $x$ and vice versa.
|
From common knowledge we know that all massless particles move at the speed of light, is that right? If so, since they move at speed of light they don't experience time but particles with mass can't obtain speed of light (at most they can reach near the speed of light). Does this mean time is a manifestation or result ... |
Suppose that some frame satisfies Newton's second law, so that $F_{net} = ma$ for all particles in the frame. Does this imply that the frame satisfies Newton's first law? This seems to be the case, since if $F_{net} = 0$ and $m > 0$ then we must have $a = 0$.
I read some other answers on this site which state that we c... |
In this question Can hydrogen atom exchange induce attractional forces between $e^-e^-$? one answer showed the range of exchange particle but not how to calculate. how do we calculate/know what are range of exchange particle? Do we calculate or observe?
|
When taking a static approach to finding the spring constant $k$, the only improvement I can think of is modifying the length of the string attached to the spring and weight. Can anyone provide some hints or guide me in the right direction on how I can further improve a static spring setup?
I'm suppose to come up with... |
Water is running through a pipe. The pipe is heated uniformly in order to heat the water running through the pipe. I want to calculate how much heat needs to be generated by the pipe in order to heat the water by a certain amount, e.g. from 10C to 30C.
I found a formula for this here - https://www.youtube.com/watch?v=7... |
For an operator $F$, its (Hermitian) adjoint, $F^\dagger$, is defined as an operator satisfying
$$\int f^*F^\dagger g~\mathrm d^3r=\int(Ff)^*g~\mathrm d^3r,$$
for any arbitrary functions $f$, $g$ such that the integrals exist.
But what is the guarantee that such an operator, $F^\dagger$ with this property exists for an... |
Newtonian mechanics seems to allow for both positive and negative gravitational mass as long as the inertial mass is always positive. The situation is analogous to electrostatics but with the opposite sign. Two positive masses or two negative masses are attracted to each other whereas one positive and one negative mas... |
Almost every textbook and a journal article that deals with thermal noise in the context of optical fields (such as signal processing, micro-ring resonators, laser sources, etc.) assumes that the autocorrelation function of the thermal noise in the system (whether it be studied from a quantum or classical point of view... |
I am currently doing an experiment looking at the energy distribution of photoelectrons in the photoelectric effect.
I have done some data collection for different wavelengths of light, and have the following results:
I understand there is no direct link between photocurrent and backing voltage, however I found this e... |
If the speed of light in vacuum is constant to every observer then how is the shifting of light color possible?
I am assuming that a single particle of light (a photon?) has the capability to contain a light property. If true then
What is happening to the photon when it is getting color shifted?
bearing in mind tha... |
Consider FCC lattice, let lattice vectors are
$$
\vec{a}_1=a\hat{x}, \quad \vec{a}_2=a\hat{y}, \quad \vec{a}_3=a\hat{z}
$$
then basis are $(000),(\dfrac{1}{2}00),(0\dfrac{1}{2}0),(00\dfrac{1}{2})$, hence structure factor is
$$
S(v_1,v_2,v_3)=\sum_{j}f\exp(-2\pi i(v_1x_j+v_2y_j+v_1z_j))=f(1+\exp(-\pi i(v_1+v_2))+\exp(-\... |
View from A
View from B
View from C
In the familiar experiment to derive time dilation we have observer A traveling with a light clock. The light clock sends a light pulse from the roof of the spaceship bouncing it off a mirror on the floor (one tick event). A observes the light pulse moving through twice the height... |
Please help me find the the representation in $k$-space (Fourier transform) of the following function:
$$
f(k_t, k_z, m) = J_m(k_t\rho)\exp(ik_zz)\exp(im\phi)/N
$$
The properties of $f$ given below might come in handy. The equations are from a paper by S.J. Van Enk and G. Nienhuis(2007) (https://doi.org/10.1080/0950034... |
Rotational mechanics is a very interesting subject. However, in the common relativity textbooks not much discussions on rotational mechanics can be found. Is there any source/books where I can find a very detailed discussion on relativistic rotational mechanics/dynamics?
|
When a plane has a slope due to the x-axis, and a ball has an initial $V$ along the $y$-axis. It is natural that we should concern kinetic friction along the $y$-axis.
But I am confused with should I concern what kind of friction along the $x$-axis.
If we adopt 'independence', we can consider the ball's movement as a s... |
I guess one has to assume low intensities? What are notable differences in a full quantum treatment?
I'm familiar with the semi-classical theory of atomic transitions (coupling classical field to quantized atom), but don't know anything about quantization of the EM field. I'm mostly interested in the consequences, no e... |
Good day! I'm having trouble comprehending this question.
Write the equation for a standing wave that has three antinodes of amplitude 2.00 cm
on a 3.00 m long string that is fixed at both ends and vibrates 15.0 times a second. The
time t = 0 is chosen to be an instant when the string is flat. If a wave pulse was
prop... |
I've done several calculations on one-loop diagrams in dimensional regularization, involving things like Feynman parameters, or using hyperspherical coordinates after a Wick rotation, s.t. you can drop terms like $p^\mu a_\mu$ in numerators, or replacing $p^\mu p^\nu$ with $\eta^{\mu\nu}/d$.
However, when it comes to t... |
I've been looking around for a way to calculate the humidity ratio by the partial vapor pressure and the atmospheric pressure of the environment.
I found a procedure for such calculation on engineering toolbox (https://www.engineeringtoolbox.com/humidity-ratio-air-d_686.html).
There, it is explained that:
Based on the... |
I came across this problem in N. Zettili's Quantum Mechanics book (Chapter 9, Problem 16):
Two identical particles of spin 1/2 are enclosed in a one-dimensional box potential of length L
with walls at x=0 and x=L. Find the energies of the lowest three states.
This is a solved exercise. And the solution says that
Sin... |
Lets say that I have a Hermitian Hamiltonian $H$ with a non-Hermitian raising operator operator $A$ which satisfies
\begin{equation}
[H,A] = \Omega A, \quad \Omega \in \ \mathbb{R}_{>0}.
\end{equation}
Then it is fairly straightforward to show that $H$ has a symmetry in the form
\begin{equation}
[H, AA^{\dagger}] = 0.... |
Above is the image of an object made to revolve in a vertical circle. The tension of the string at any point is also given in the above image. But my question is, shouldn't the equation be as below? Also, what is $W\sin \theta$ here? Is it reducing the velocity of the object since it's acting in the opposite direction... |
The product of annihilation operator with zero ground state of a harmonic oscillator is zero since energy cannot be negative or less than zero. I understand this explanation but what is the intuitive explanation of its conjugate operator i.e creation operator when operating on bra is also zero ?
I understand this part,... |
I'm trying to find the force on a magnetic dipole $m_2(r,0,0)$ on the x-axis due to the magnetic field $\vec B_1$ produced by a another dipole $m_1(0,0,0)$ which is at the origin. Both magnetic points $\vec m_1$ and $\vec m_2$ point in the positive x-direction
I've made the assumption that a dipole can be modelled as a... |
A classical harmonic oscillator has energy given by $\frac{1}{2m}p^2+\frac{1}{2}kx^2$. This means its Boltzmann factor is
$$e^{-\frac{\beta p^2}{2m}}e^{-\frac{\beta k x^2}{2}}$$
where $\vec{x}$ and $\vec{p}$ are the continuous position and momentum vectors, respectively. The partition function should therefore be given... |
Consider a solution to the wave equation $ \psi\left(x,t\right) $, then using Fourier transform, we can represent:
$ \psi\left(x,t\right)=\left(\frac{1}{2\pi}\right)^{2}\int_{-\infty}^{\infty}\int_{-\infty}^{\infty}\widetilde{\psi}\left(k,\omega\right)e^{i\left(kx+wt\right)}dkdw $
Now if we'll apply this form into the ... |
In this Making Logic Gates from Transistors video by Ben Eater, he says the voltage drop will occur at a node in a parallel circuit. But in my knowledge, in parallel circuits, voltage remains the same in branch points; it's rather the current that's separated due to charge conservation.
For clarity I will write down wh... |
I always wonder how the formula for moment of inertia is actually derived. Some say that moment of inertia is simply equals to $MR^2$ but some derive it saying moment of inertia is directly proportional to mass and distance squared, but I want a killer explanation why is it proportional to distance squared from the axi... |
imagine trivial induction scenario of static loop in variable magnetic field.
So the emf is the total work per unit charge that a charge in a e.g wire will gain as a result of moving through a path in a vector field.
I am completely fine with the idea that IF a charge were to be forced to move in a certain path then th... |
I have been trying to prove that two Bloch states with wavector k and k + (2pi/a) are identical, as the book says:
can anyone help me?
I have look at some more sources in the solid-state physics, and all of them say that that the block state is periodic in reciprocal space but they never prove it.
|
I'm having some trouble with this part of Sakurai's derivation of the time evolution operator in QM (page 70):
Because of continuity, the infinitesimal time-evolution operator must reduce to the identity operator as $dt$ goes to zero, $$\lim_{dt \to 0} \mathscr{U}(t_0+dt,t_0)=1,$$ and as in the translation case, we ex... |
What does it mean by exchange of matter and energy means here?
|
Let us consider a quantum mechanical system of interest S that interacts with the environment E. Then, the reduced density matrix
$$
\hat \rho_\mathrm{S} = \mathrm{Tr}_\mathrm{E} \{ \hat \rho \}
$$
is the partial trace over the environment, where $\hat \rho$ denotes the density matrix of the complete system (S + E)... |
I am a high school student and I am very confused in a topic which involves "WALKING" and it is majorly related to friction,
This is a question from a very famous book called "Concepts of Physics" and all the questions given in this book are very conceptual without any wrong answer and the answer to this question{ whi... |
I've been calculating the possible isospin states for $\pi^0\pi^+\pi^-$ state and get this as my final answer after referencing the Clebsch Gordan Coefficients table:
$$\frac{1}{\sqrt{10}}|30\rangle+\frac{1}{\sqrt{3}}|20\rangle+\frac{\sqrt{5}-1}{\sqrt{15}}|10\rangle-\frac{1}{\sqrt{6}}|00\rangle$$
However, if I square t... |
I am a bit confused with the following formula
why is that the normal stress ($z$), not the normal stress ($x$), is involved in the formula for the moment around $x$, $Mx$?
Likewise, My also equals the integral of normal stress ($z$) and distance $x$
$$M_x=\int \sigma_z y dA$$
|
I am trying to understand how to build the spectrum of the angular momentum; of course since different components of the angular momentum do not commute with each other we must chose only one component to focus on: let's say we choose the $L_z$ component, and so we want to find the spectrum of $L_z$. We also know incid... |
why some electron transition in the orbits are more likely to happen than others?
I am a second year physics student, so I don't have much physics knowledge
|
How can we experimentally measure the wavelength of gamma-rays, say for about 0.7MeV without knowing the exact energy and without measuring energy, i.e. sort of direct measurement.
|
So I am trying to understand in which sense first and second quantization is equivalent. I am following Richard Martin's book on interacting electrons. In the appendix (A.2) he has a piece on second quantization. My understanding of it is that:
First quantization:
A state is a square-integrable function.
Second quantiz... |
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