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If dark energy drives a repulsive force between galaxy clusters, proportional to their distance which makes space expand, which creates space between them, and gravity between the clusters has the opposite effect, if it tends to shrink, to annihilate space between the clusters, then gravity only might slow down the exp... |
As the solar system formed, why didn't all of the heavier elements such as iron, collect where the sun is leaving the lighter elements in the outer solar system?
|
I was watching a video on relativity on YouTube that talked about the difference between coordinate time $t$ and proper time $\tau$ and I have a couple of questions.
As I understand it, the video said that the coordinate time $\Delta t$ along a path between two events is the time between the two events measured by a fa... |
In the usual formulation of lattice gauge theories, one considers gauge variables on the links of a lattice (often hypercubic) taking value in some representation of a gauge group, $U_{ij} \in G$. The action can generally formulated as the sum of Wilson loops around plaquettes,
$$S_p = \beta \sum_{\square}\mathrm{Tr}\l... |
Two well-known coordinate charts on the dS spacetime are the global coordinates and the static patch coordinates. In the global coordinates, the D-dimensional dS metric takes the following form
$$ ds^2 = -dt_g^2 + l^2 \cosh^2(t_g/l) d\Omega_{D-1}^2$$ where $t_g$ is the global time and $l$ is the radius of the dS space.... |
Many physical phenomena are associated with unbelievably small time scales. Let me give a few examples.
The time scale associated with visible light is $\sim$ a femtosecond ($10^{-15}$ sec),
The half-life of a neutral pion $\sim$ an attosecond ($10^{-18}$ sec) etc.
Many more examples can be found here.
Do we have e... |
I have studied physics up to 12th grade and I noticed that whenever new equations are introduced for certain entities, such as a simple harmonic wave, we never prove that it's continuous everywhere or differentiable everywhere before using these properties.
For instance we commonly use this property that $v^2\cdot \fra... |
I've got a BSc in Physics and passed all courses on classical mechanics, but whenever I have to face a problem concerning circular motion, I don't know why, but I'm always confused and keep having to open the book learn everything again instead of being able to do stuffs by myself. Even the high school level stuff, I t... |
I'm trying to learn the concept of quantum dots and coulomb diamonds, and I'm trying to read this but I have encountered a problem which I couldn't find answer online. On the 4th page it mentioned:
By tuning the gates it is possible to tune $\tilde{\mu}_{N+1}$ to lie between the electro chemical potentials in source a... |
There is a mass A attached to a horizontal spring fixed at an end. An equal mass B comes along and hits the mass with velocity $v$. Can I use the equation of motion $v^2=u^2+2as$, to calculate the acceleration of the masses after the moving mass hits the one on the spring and the spring gets compressed?
I got the final... |
You're trying to reconstruct the density matrix by sampling a signal.
If you measure spins coming from a source along the Z axis, and 50% of the time they are spin up and 50% spin down, how do you know if the signal is a mixed state or a pure state? Do you have to also measure along an orthogonal axis, such as the X ax... |
I want to know why is it preferred that the classical universe is seen as an affine space instead of a vector space?
From my understanding an affine space violates the zero vector in the vector space.
Because of this this is it same to assume
Let $a,b\in A$ Where $A$ is an affine space
$ca \in A$ is false
$a + b \in A$... |
We know that the heat supplied is directly proportional to the change in temperature. But during fusion and vaporization, the temperature is the same i.e $d T=0$. Is the equation invalid in these process?
|
My question is rather general and it regards the possibility to associate the Boltzmann probability distribution to some energy model.
What are the general assumptions that an Energy-based model needs to have, in order to be described by a Boltzmann probability distribution?
Furthermore, is it possible to extend this t... |
In the text The Physics of Quantum Mechanics by Binney and Skinner, the authors define $| \psi \rangle^\dagger \equiv \langle \psi |$ and $\langle \psi |^\dagger \equiv | \psi \rangle$. How can one justify that?
It is written in the book that
If we agree that the Hermitian adjoint of a complex number is its complex co... |
Consider the hamiltonian
$$
H = - \frac{1}{2} \nabla^2 + V.
$$
The potential $V : (\mathbb{R^3})^N \to \mathbb{R}$ is symmetric, so for each eigenvalue, there is an antisymmetric eigenvector. There is not any spin operator inside $V$. It can be assumed that the hamiltonian describes a fermionic many-body problem.
Suppo... |
In the paper "Les Houches Lectures on Black Holes", we have the action given as: (Eqn 3.6),
$$ S = \int d^2x \sqrt{-g} e^{-2 \phi } [R + 4(\nabla \phi)^2 + 4 \lambda^2] $$
This is a 1 + 1-dimensional theory of gravity coupled to
a dilaton field $\phi$. The equation of motion for dilation field $\phi$ is obtained as Eq... |
I will try and describe my observations the best I can.
I placed a candle in front of me and my spectacles a bit further ahead of the candle. I have negative power so my spectacles must be concave. I tried to see the image formed from behind the candle and noticed two things :
There were two images formed, one of them... |
As an introduction, I am a computer engineering student that want to create an arduino project in which it use water temperature as its parameter. The temperature will help the microcontroller choose whether it should turn on the heater or not. But in planning this project, I cannot decide how many heater and how many ... |
I would like to see how my model I am working on behaves in the limit of infinite dimensions so I get a little bit of intuition for the low dimensional case. In the paper I am reading they have a transverse Ising model:
$
H = -J \sum_{<i,j>}\sigma_i^x \sigma_j^x+\Delta \sum_i \sigma_i^z
$
with an additional way of sp... |
I'm aware that, according to the Pauli principle, identical fermions obey the Fermi-Dirac statistics, so they don't occupy the same state because they just can't, it's simply how they behave. I'm wondering, are there any different interpretation about this that don't postulate it as a principle but describe it in terms... |
It is predicted in string theory that our world has some extra dimensions. I'm wondering if we want to prove this experimentally, what should we do
|
I took a dive into the concept of information in physics and from what I have read, I which someone to confirm if looking at something really modify the state of that thing.(modify state here refers to any small change in the object "information arrangement")
|
Let's assume there exists a partition function $Z[J_i]$ for a theory of quantum gravity, with a family of sources $(J_i)_i$. Given the Palatini action in 3+1 dimensions:
\begin{equation}
S_P[e,\omega]=-\beta \int d^4 x\,e\,e^\mu_I e^\nu_J \Omega^{IJ}_{\mu \nu}
\end{equation}
(with $\Omega=d_\omega \omega=d\omega+\omega... |
I have been given an equation, without an explanation on the constant included.
The equation is the following: $$\Gamma= \frac{7\pi}{24} G^2_{\text{Fermi}}$$
When looking for a value for the Fermi Coupling Constant, $G_{\text{Fermi}}$ , I only seem to find values for $G_{\text{Fermi}}/{(\hbar c)^3}$.
To obtain the valu... |
In some of the physics problems I have done, the solution involves taking a snap shot right before collision and analysing the angles between the bodies. The angles between the bodies are supposedly same as angle between velocity components but I do not understand why it would be generally?
Example:
A ball with with ... |
I'm trying to follow Tong lectures about Gauge Theories, but I think I'm doing some really stupid mistake.
At one point he takes the Hamiltonian for a spin $1/2$ particle in a potential as the usual
\begin{equation*}
H=(\mathbf{p}-e\mathbf{A})\cdot\mathbf{\sigma}
\end{equation*}
Where $\mathbf{p}$ is the momentum, $\ma... |
I'm studying the 1-D SSH model. It's a toy model for a topological insulator. Here's the reference I'm using. If the hopping amplitudes $v$ and $w$ are equal, then with periodic boundary conditions we have a conductor. If however, we take open boundary conditions, a plot of the eigenvalues shows that there is a band ga... |
I want to preface this by saying that I'm by no means experienced with the field of physics, but while on my commute this morning, I started thinking:
Basically, I thought about time being a fourth dimension, time dilation, and whatnot (it was very early), and I thought about how if we're moving at one second per seco... |
I read this excellent article on the Conservation Laws and also I was taught in Schools that Conservation Laws cannot be proven and only verified. I was wondering what would actually happen if a Conservation Law turned out to be false?
I know it would question our measurements as well as our calculations as we use them... |
Suppose I used a polarized film to produce say left circularly polarized light, I wonder what happens to the rest of the light that gets absorbed or reflected away? Are those unpolarized or right circularly polarized?
|
I am conducting an experiment, where I will be finding the centripetal force of a hula hoop using the mass ($m$), period ($T$), frequency ($f$), radius ($R$), velocity ($v$), by $v = \dfrac{2πR}T$. By multiplying $v$ by $m$, I will be able to calculate the centripetal force.
However, in order to calculate the % error o... |
In general, an EM wave within a lossy medium is expressed as
$\mathbf{E}=\mathbf{E_0}e^{-\gamma_x x-\gamma_y y-\gamma_z z}$.
If we consider $\mathbf{\gamma}=\gamma_x \hat{x}+\gamma_y \hat{y}+\gamma_z \hat{z}$ and $\mathbf{r}=x\hat{x}+y\hat{y}+z\hat{z}$, the above equation is expressed as
$\mathbf{E}=\mathbf{E_0}e^{-\ga... |
This is a purely speculative question and one that is motivated by discrete computational models of space. In particular, I am wondering if there is a worked out mathematical model of physics such that the Planck length is not constant but either arbitrarily smaller or larger than it's presently agreed upon value.
An e... |
As far as I know, darts, arrows, and airplanes have the center of gravity(CG) ahead of their center of pressure(CP) and often have fins at the rear to achieve stability. Contrary to these, bullets have CP ahead of CG and they do not have fins. Thus, how do bullets acquire stability?
|
In thermofield dynamics, which constitutes an algebraic formulation of thermal quantum field theory, an entropy operator $\hat{S}_\beta$ for a single bosonic oscillator is introduced as
$$\hat{S}_\beta=-k_B\,(\hat{a}^\dagger \hat{a}\,\ln\,\sinh^2\theta_\beta-(\hat{a}^\dagger \hat{a} +1)\,\ln\cosh^2\theta_\beta)$$
with ... |
How does Feynman get to $D^2_{N-1}$?
The expected value of $D^2_N$ for $N>1$ can be obtained from $D_{N−1}$. If, after $N−1$ steps, we have $D_{N−1}$, then after $N$ steps we have $D_N=D_{N−1}+1$ or $D_N=D_{N−1}−1$.
And could someone help me with this sentence?
In a number of independent sequences, we expect to obtain... |
I am currently studying Physics of Photonic Devices, second edition, by Shun Lien Chuang. Chapter 1.3 The Field of Optoelectronics says the following when discussing semiconductor physics:
For example, by controlling the mole fraction of gallium and indium in an $\mathrm{In}_{1 - x}\mathrm{Ga}_{x}\mathrm{As}$ material... |
My question is very simple. Can we use electrostatic force of repulsion to project objects; By charging that object(movable) with the same charge to another static object (non moving) in a close system so that all the resultant force is exercised only on the moving object setting it in motion?
|
According to the table in wikipedia, there are multiple contributing factors that add to the precession of Mercury's orbit.
What I am curious about is, how do we know these factors can be evaluated independently and then added together?
I also have two follow-up questions.
If the effects don't combine linearly, how d... |
I'm trying—unsuccessfully, as of yet—to follow how the second half of equation 1.56 is derived in Solid State Physics by Ashcroft and Mermin (equations below). Please keep in mind that I'm using this inaccurate derivation of thermopower for a high school research essay, so I'd appreciate it if things could be explained... |
Disclaimer: I am an amateur, and an experimentalist and don't understand the equations involved.
Intro: Fermions and bosons are (we're almost definitely sure this time) fundamental particles. Fermions have mass and make everything up so I don't trust them. Bosons are field particles like the photon. Quantum Field ... |
This question stems from an answer to the following question:
What's the most fundamental definition of temperature?
The issue here is how to define the temperature in a system not in thermal or thermodynamic equilibrium. Is there a fundamental definition beyond just calculating the second velocity moment in the popul... |
In the weak field limit, gravitational radiation can be treated by the linearized theory and then its properties are very much like those of electromagnetic radiation, except we are dealing with the perturbations to the metric tensor, as opposed to the electromagnetic field tensor. I mean they are alike in that one has... |
This has confused me for some time: if one integrates the gravitational force between two radii (let the motion of the particle always point toward the centre of mass of the other mass) from a radius which is further from the centre of mass than the other radius, to the radius which is closer to the centre of mass (in ... |
I thought I had the conceptual understanding of how magnetism between a charged particle and a current carrying wire can be seen from the point of view of relativistic effects, but after revisiting the concept, I got conceptually stuck.
The easiest way to show my issue is to reference this video (between 1:20 and 2:30)... |
Which phenomena is responsible for this kind of backward curled flow of the fluid (air)? Kindly if anyone knows about it,please explain.
|
I am in high school, and today my physics teacher was teaching us about the Earth's magnetism. This is the first time I've read about this topic, so take these questions as coming from a complete layman.
From what I understood, the magnetic field around the Earth exists because of the rotation of the Earth. The mantle ... |
My question is as follows, below this I have included derivations of both effects:
The derivation of Bloch Oscillations implies that in a perfect crystal we will not have net current flow when an electric field is applied.
However, the ballistic transport derivation shows that, regardless of crystal quality, we will ha... |
Why there seems to be different conventions of QCD energy scales? Is that due to the running coupling?
For example in Wikipedia https://en.wikipedia.org/wiki/Coupling_constant#QCD_scale:
$$
\Lambda_{\rm MS} = 218\pm24\text{ MeV}
$$
and also some search of the article https://inspirehep.net/literature/296684:
$$
\Lambda... |
According to special (& galilean) relativity, there is no difference between constant movement or not moving at all but it is possible to detect acceleration and rotation is acceleration.
The earth rotates around the sun and the sun rotates around Sagetarius A* (the black hole in the center of the milky way).
So, there... |
So I am studying classical mechanics through the MIT 8.223 notes, and encountered the derivation of the Euler Lagrange equation. There is a part I don't quite understand, which resides in the actual meaning of the $\delta$ symbol here. We define the action $S[q(t)]$ as the integral from $t_1$ to $t_2$ of $L(q,\dot q,t)... |
Consider the Einstein-Maxwell-dilaton theory with an additional Chern-Simons term as in this paper
\begin{equation}
S = \int d^4 \sqrt{-g} \left[ \frac{1}{2} R - \frac{1}{2} (\partial\varphi)^2 - \frac{\tau(\varphi)}{4} F^2 - V(\varphi) \right] -\frac{1}{2} \int \theta(\varphi) F\wedge F.
\end{equation}
with $F=d A$ b... |
Let’s consider a hypothetical situation wherein an observer is in the standpoint of a light ray. The observer faces infinite time dilation. Thus time stops for the observer and it'd have transversed an infinite distance for any finite time to pass for a stationary observer. What should we conclude from this?
The univer... |
Diamond is quoted as having a dielectric breakdown strength of about 2 Gv/m on wikipedia:
https://en.wikipedia.org/wiki/Dielectric_strength
This 2 Gigavolts/meter value being the electric field strength at which diamond stops being an insulator and starts conducting current.
Are there any materials with a higher breakd... |
The reason we smell fragrance from a far distance is due to the diffusion of its molecules. But which force causes this diffusion?
Which forces cause the material to propagate from higher density to lower density regions?
|
In trying to derive Maxwell's equations from
$$S=\int d^4 x\left(-\frac 1 4 F_{\mu \nu}F^{\mu \nu}\right)$$
Where
$$F_{\mu \nu}=\partial_\mu A_\nu-\partial_\nu A_\mu$$
I'm trying to show that
$$\frac{\partial (F_{\mu \nu} F^{\mu \nu})}{\partial (\partial_\lambda A_\beta)}=4 F^{\mu \nu}$$
But there seems to be something... |
In a world of two-dimensional beings, How would a two-dimensional (A) being view another two-dimensional (B) being as? Would they always perceive each other as a straight line?
|
I answered a question about a "vacuum balloon" and came up with a problem I feel should be simple, but I cannot find the answer. Imagine a zero-drag balloon of a density $a$. It floats up to a height $h$ against gravity of constant acceleration $g$ (we assume small $h$ relative to Earth's diameter). The atmospheric den... |
I want to block all EMF transmissions -- tv, radio, cell phone, wifi etcetera. I'm not trying to protect myself from an atmospheric detonation or solar storms, just the RF / EM "noise" of modern life.
I envision solid conductive foil / sheets on all walls, with "shutters" over the windows and door, and maybe flaps over... |
From here, I'm trying to integrate out the massive fields of the $D0$ brane action, expanded around a classical background. I have a ghost action with complex fields:
$$S_{GH} = i \int d\tau \overline{c}_{1} (- \partial_{\tau}^{2} + r^{2}) c_{1} + \overline{c}_{2} (- \partial_{\tau}^{2} + r^{2}) c_{2} - \overline{c}_{3... |
If we have an object of a certain mass that's moving on a non-friction floor with a certain velocity v, and we suppose that at some point we take off half of the mass of that object, does the velocity increase to 2v - since the system is closed so the momentum is supposed to be conserved - , and if it does, how so? re... |
Suppose there is a vector $\vec v$ which is a function of time, then will $\dfrac{d}{dt}|\vec v|$ be a vector quantity or a scalar quantity?
I think it should be scalar because, let's assume $\vec v=2t\hat{i}$.
Then $|\vec v|=2t$, and
$\dfrac{d}{dt}|\vec v| = 2$ which is just a magnitude and has no associated direction... |
Conservation of momentum is Newton's third law. Conservation of energy is attained in theory by defining work, deducing the work-energy principle and specifying that if a force or system is conservative, then that which changes when work is done (energy) is always matched with a change of opposite sign at the same time... |
We're talking vertical loop.
So let's assume the loop structure is hyper strong and not prone to any structural damage.
Going with a fast car's top speed of let's say 350 km/h = (roughly) 100 m/s...
Plugging that into one of the rudimentary centripetal force equations:
\begin{array}{l}
v=\sqrt{g\cdotp r}\\
\\
\frac{v^{... |
Two related questions regarding the equal-time commutation relation in the Klein-Gordon field (I suspect they have the same/very related answers):
In the following notes http://www-thphys.physics.ox.ac.uk/people/FabianEssler/C6web2012/theory/canonical.pdf, they have:
My question is going from the second to the third l... |
In a regular fermionic system (such as a Fermi liquid), the Green's function is given by
$$ G({\bf k},\,\omega)=\frac{1}{\omega-\epsilon_k-\Sigma-i\delta}$$
where $\Sigma$ is the fermionic self-energy. My question is can we write the Green's functions for composite fermions at arbitrary filling factor $\nu$ in a simila... |
Question 1
I was trying to understand why cosmologist calculate the matter fluctuations in spheres of $8 h^{-1} Mpc$. I look for information and I find that in this scale the fluctuations become non-linear, but I can't understand how they conclude that. Why not calculate the matter fluctuations in spheres of $0.8h... |
A super child aboard a space ship moving at 0.7c throws a 50 cm ruler towards the front of the ship at a speed of 0.4c (relative to the ship). If a stationary observer observed the ruler, how long would it appear?
I'm assuming I should use the length contraction formula, but from what I understand that formula is for t... |
If you carry a book in your hands, and you walk up stairs with a change in height of $h$, the net work on both you and the book would be $-M_{\mathrm{total}}gh$ since $W = - \Delta U$. This would be due to gravity.
However, when considering the book alone, the work done by the normal force, i.e. your hands, would be $M... |
I understand second quantization, and how absorption and spontaneous/stimulated emission works for an electron in $m$-level system. In other words, I know how a photon with the right frequency can take an electron from the $n^{th}$ energy level to the $(n+1)^{th}$ energy level (and vice versa).
Using the electric dipol... |
I was studying the phenomena of particle diffraction and saw that any particle can be associated to a de Broglie wavelength, given by $$λ=\dfrac{h}{p}$$
Experimentally, we commonly talk about the electron diffraction in a crystal, which was a very important experience to the quantum theory. An electron has relatively l... |
I'm familiar with the basic idea of what a wormhole (Einstein-Rosen bridge) is and have seen many varied visualizations of what it would perhaps look like if you met one. I have several questions that really have been bothering me for a long time.
Where does the other end of a wormhole lead to when it's created?
When o... |
In "Analytical Mechanics" by N. A. Lemos, in page 99 the author determines the time derivative relation between an inertial frame $\Sigma$ an an non-inertial frame $\Sigma'$ fixed in a rigid body with angular velocity $\mathbf{\omega}$ around its origin $O$, such that $$ \left(\frac{d}{d t}\right)_{\text {inertial}}=... |
Lets say that we have a spring, with spring constant k. It has an orignal length of $l_1$ and after stretching it a length of $l_2$. Now lets take and element of length of $\Delta$l.When the spring was stretched I wanted to find out how much does this element stretch. Online I found a answer which said that as all elem... |
Without going deep into mathematics and simply using symmetry arguments I made the following observations-
An electron has a probability of being at a particular position
Let's take the 1s orbital of a Hydrogen like single electron species and a uniform sphere at some distance $r$ from it.
By Symmetry we can conclude ... |
The proton radius puzzle appears to one of the more widely known unsolved problems in physics, but doesn't it point to a much deeper issue? Nearly all of a baryon's observed mass can be attributed to the (kinetic) energy of the quarks they are comprised of. It is my understanding that their radius is also a consequence... |
I often encounter discussions, such as seen here, about whether spacetime is discrete or continuous. However, I am only familiar with continuity as being a property of functions. I saw this question about continuous spaces, but I didn't find a definitive answer there, so I ask what is meant when we say that spacetime i... |
I am a mechanic trying to gain a better understanding of electrical theory on vehicles. I have a sound understanding of Ohm's law and also the power formula (Power = Voltage x Current)
However, I am just trying to understand when to use each one in the case of diagnosing the electricals on a vehicle.
When assessing a l... |
after reading about diffraction I am confused on how its effect came to be understood.
Can one derive diffraction from the wave equation and base principles or is it a result of empirical observations?
|
When $24.8 keV$ x-rays strike a material, the photoelectrons emitted from K shell are observed to move in a circle of radius $23mm$ in a magnetic field of 2 × $10^{-2}$. The binding energy of K shell electrons
Now the solution is something like this
My doubt is why have they equated $evB$ to $Mv^2/R$??
|
In Srednicki pg.136, he derives the Schwinger-dyson equation from:
$$
0=\delta Z(J)=i\int D\phi \, e^{i[S+\int d^4y\, J_b\phi_b]}\int d^4x(\frac{\delta S}{\delta \phi_a}+J_a)\delta\phi_a.\tag{22.21}
$$
Then we apply $n$ functional derivatives wrt. $J$ on it, and we can get:
$$
\begin{align}0=&\int D\phi e^{iS}\int d^4x... |
Viziv Technologies is a company that claims to be able to transform power delivery, signaling and safety. Their "Science" page says:
The Zenneck surface wave is a technological breakthrough enabling the world to “cut the cord” between power generation facilities and local distribution grids. This new technological dev... |
There is something I hope you can help me understand...
According to my physics course, when I stand on the surface of earth, the normal force prevents me from "falling down" because it's acting opposite to the direction of gravitational force. Hence my net acceleration is $0$.
According to what I think, gravity is acc... |
I have read that heat radiation happens in the form of infrared, which is an EM radiation with a longer wavelength than visible light. So the heat radiation that you can feel in an oven or under the the sun is actually the infrared portion of the total radiation. This is why fluorescent or LED lights are so bright but ... |
In physics, can we legally add two physical quantities that behave differently under time-reversal or parity? For example, let $\vec{a}$ and $\vec{b}$ are two observables. Let $\vec{a}$ flips sign under time-reversal (or parity) but $\vec{b}$ does not. For example, $\vec{a}$ is velocity and $\vec{b}$ is the angular mom... |
What is the working principle of a thermocouple?
Apparently, it isn't the contact voltage but, well, what is it? Finally it seems to be about the thermodiffusion but there is quite a lot going on so I would like to have an explanation in one or two sentences which I can use as a basis to dive deeper while I know where ... |
So here is the condition. There are 3 charged particles, all three of them have the same charge, but they have different masses and all of them are moving with the same velocity. In a magnetic field, will they experience the same force?
My teacher said that they would experience different forces because they have diffe... |
In Kleppner and Kolenkow chapter 13, they derive the expression of relativistic mass by considering a symmetric glancing elastic collision.
It was analyzed from two reference frames. One in which the velocity of A in the x direction was zero and another one in which the velocity of B in the x direction was zero.
Here... |
I'm studying the SSH model, here's the reference. I don't get what the definition of a topological invariant is in this case. I think the important property is that the winding number cannot be changed without either breaking a symmetry of the system or closing the bulk band gap, but why do we call it a topological inv... |
I am looking for review papers / online talks on Chern-Simons theory with particular focus on the gravitational dual description within the AdS/CFT framework.
|
I am studying a set of notes by Ellen Kuhl of Stanford university on continuum mechanics, where I encountered the rate of deformation and spin tensors, as discussed in this set of notes. This set of notes are used in a 2008 (graduate) course on continuum mechanics at Stanford. I am not sure if this set of notes have be... |
I can't sure what isotopes of silver(107 or 109) was used.
But Silver has non-zero nuclear spin since the number of proton and neutron are not even.
Since we use Silver atom not electron in SG experiment,
I think we need to consider spin of electron and silver nucleus simultaneously.
In Sakurai text book, nuclear spin ... |
In Kepler's Third Law, the orbital period is described by
$$T=2\pi\sqrt \frac{a^3}{\mu}$$
where $a$ is the lenght of the semi-major axis. I wonder, why does the lenght of the semi-minor axis not affect the orbital period?
In this image, we have a semi-major axis ($a$) with lenght $2$, while the semi-minor axis $b$ has... |
In the kitchen the flame is blue when there is enough oxygen. Is it true that the amount of oxygen has effect in fire color, why blue, why yellow sometimes?
|
I know the uncertainty relation $\Delta x \Delta p \ge \frac{\hbar}{2}$ tells the uncertainty in position and momentum, or energy and time should be greater than or equal to $\frac{\hbar}{2}$, but I don't understand how this relation can be used to give an estimation on size of system or energy of system.
i.e. When we ... |
My question is very simple: if I have a vector field $\boldsymbol{\phi}(t,\boldsymbol{x})$ defined inside an $n$-dimensional manifold $\mathcal{M}_n$ to which $\boldsymbol{x}$ belongs, why should it be $\boldsymbol{\phi}(t,\partial\mathcal{M}_n)=0$? What I mean with this abuse of notation is, why should the variation o... |
I am curious as to how a standing wave of circularly polarized light may be forced to resonate in a Fabry Perot cavity as in this paper - https://doi.org/10.1103/PhysRevD.98.035021
I know that in a standard Fabry Perot cavity with incident linearly polarized light, the standing wave produced has the magnetic and electr... |
Einstein's equivalence principle (EEP) states:
"Locally, a free-fall frame in a gravitational field is equivalent to an inertial frame in space in the absence of a gravitational field".
However, the reason justifying this locality is that the gravitational field of any planet converges to the center of mass, and if we... |
This may seem like a very simple question, but I've been agonising over it for days. What is the probability, $p$, that two chemical species with binding energy $E$, will be bound.
My first instinct is that
\begin{equation} \tag{1}\label{1} p = Ae^{-\beta E} \end{equation}
with A some normalisation factor. This would g... |
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