instruction stringlengths 31 24.3k |
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If I understand correctly, the definition of expectation value of an operator, $\hat{Q}$, is $\int \Psi^* \hat{Q} \Psi dx$. But why $x$ specifically? If we want the expected value of the energy operator, for example, shouldn't we perform a change of basis on $\Psi$ so it's in terms of energy and then integrate w.r.t.... |
My understanding is that the primary methods with which one can create a radioactive isotope are 1) just waiting for the isotope you want (by means of nuclear decay), or 2) some kind of induced radiation, where a stable material is bombarded with nuclear particles to create a radioactive isotope (as occurs in the proce... |
In my cosmology course I came across the universe with the equation of state
$$
P=\frac{\epsilon}{\epsilon+1},
$$
where $P$ is the pressure and $\epsilon$ is the energy density. The task was to figure out which energy conditions this satisfies and do some calculations but it was provided without context. I am wonderin... |
It is clear that the total energy in a full gravitating $N$-body simulation should be conserved, but what about the energy of an individual particle? Is this not conserved, since the potential is itself time-dependent (due to interactions between particles)?
Alternatively, is the hamiltonian for a single particle in an... |
I am reading the book gravitation from Weinberg. On page 93 he states the principle of covariance. I attach a screenshot below. I think Weinberg is saying (below the enumeration) that the principle of covariance implies the principle of equivalence. I understand that. But I feel like that the principle of equivalence d... |
So my lecturer used to say "you cannot separate kinematics and dynamics in general relativity". Can someone make this statement more accessible (and precise) with an example or otherwise?
Like from Newton's laws of motion which basically goes like:
An object at rest remains at rest
A body in motion remains in motion u... |
For a canonical ensemble, I wonder if the partition function for a system $Z(T,V,N)$ is constant or not. If it is constant, then does it follow that the system's Helmholtz energy:
$$F=-k_BT\ln Z$$
is constant as well?
If Helmholtz energy is constant, then how it is possible for a system to increase or decrease its Helm... |
I have a physics problem that's a bit beyond my knowledge to solve and I haven't been able to find a clear answer for that I trust. Let's say I have a 2d asteroid in the shape of a convex polygon of uniform density in space. It is rotating uniformly around its center of mass when another arbitrary event causes it to sp... |
We always hear from the community that gravity is difficult to quantize, and quantum gravity field theories have some difficulties in terms of renormalization and are associated with quantum anomalies, such as,
A list of inconveniences between quantum mechanics and (general) relativity?
Why is quantum gravity non-ren... |
Suppose we have an action $S=S(a,b,c)$ which is a functional of the fields $a,\, b,\,$ and $c$. We denote the variation of $S$ wrt to a given field, say $a$, i.e. $\frac{\delta S}{\delta a}$, by $E_a$.
Then $S$ is gauge invariant when
$$\delta S = \delta a E_a + \delta b E_b +\delta c E_c = 0 \tag{1}$$
This gives
$$\de... |
Just like in my question. How to check laser beam polarization? What's the easiest experiment to do that will help me understend what type of polarization is present in my laser beam?
|
We know that at maximum height of a projectile only horizontal velocity exists.If 'u' be the initial velocity of the projectile and x be the angle of projection ....then is the following relation correct?
$$u \cos x = u - gt $$
or:
$$u - u\cos x=gt $$
or:
$$ t=u(1-\cos x)/g $$
$$T=2t=2u(1-cos x)/g $$
|
I'm trying to better understand the process of charging a capacitor with a battery. My textbook (the Halliday's Fundamental of Physics) describes this process in these terms:
When the circuit [...] is completed, electrons are driven through the
wires by an electric field that the battery sets up in the wires. The
fie... |
According to Hawking’s theory, black holes have temperatures inversely proportional to their masses and emit photons like an ideal black body. However, besides EM radiation there is also gravitational wave (GW) radiation made of hypothetical gravitons (which are not yet observed). Because gravitons are also massless, t... |
I am studying electromagnetism, in particular boundary conditions for magnetic field, and I have a question.
It is clear to me the demonstration of the normal component of the magnetic field:
$ \int (\vec{B} \cdot \hat{n}) d \Sigma = \int (\nabla \cdot \vec{B} ) dV = 0$
$ \rightarrow B_{1n} = B_{2n} $
given a surface l... |
In my statistical physics book, it is said that, when a particle with total angular momentum $\vec J$ is placed in a weak external magnetic field, it has a dipole magnetic moment equal to $$\hat {\vec \mu}=g \mu_B \hat {\vec J}$$ where $g=1+\frac {j(j+1)+s(s+1)-l(l+1)}{2j(j+1)}$ is called Landé g-factor.
However, I don... |
Can there be any solutions for simple vacuum Einstein Field Equations in 1+1D (1 space and 1 time dimension) i.e $R_{\mu\nu} = 0$ except for flat space?
I tried different combinations of random Riemann Curvature Tensor Components - it seems finding such a solution is impossible in 1+1D.
|
I would like to know if this is theoretically possible or not and if there is a way of calculating the probability of this happening.
|
I am reading a paper called Thermodynamics of Coherent States and Black Hole Entropy, written by Bashkirov and Sukhanov. If I understand correctly, they define a coherent state by the equation
$$a|d\rangle=d\ \Big(\frac{m\omega}{2\hbar}\Big)^{1/2}|d\rangle$$
where $d$ is a complex number, and together with the factor $... |
I always see diagrams of how a camera obscura works where the projected image neatly stops before or at the edges of the wall opposite the pinhole.
But when I look at pictures and videos of rooms converted into a camera obscura (usually as a fun experiment), the image often continues projecting onto the roof, side wall... |
I am currently trying to simulate a cyclist. Right now I am looking at the change of velocity when the cyclist is coasting on a plane road. These are the values I am using:
Weight of cyclist and bike: 93kg
coefficient of rolling resistance: 0.004
coefficient of air resistance: 0.490 ( frontalSurface 0.4 * dragCoeffic... |
When you produce a long-lived particle (like charged pions, muons), it enters your detector. When you produce a short-lived particle (like the higgs, tau), the production of the particle is only seen as an increase of a certain process when the collision's center of mass energy is near the particle's mass. But there ar... |
I was reading a book which contains a numerical question about largest wavelength of hydrogen spectrum in ultraviolet region. In the solution, it mentions the largest wavelength in ultraviolet region is the first line of Lyman series (122nm).
Also searching on google for largest wavelength of hydrogen spectrum in ultra... |
I am trying to understand the interaction between a transmitting antenna with a certain transmitting power (denoted PTX in the diagram) and how the radiation pattern of the TX antenna is affected by a RX antenna implanted inside the human body and by the human body itself. The purpose of this is to eventually be able t... |
I want to visualise an test EM field in Kerr spacetime (I want to plot the integral field lines). The field is a test field in the sense, that it doesn't change the background (metric).
Could anyone point me to some more technical literature or some Mathematica/python code that would help me?
What I thought I would do:... |
Everyone knows the Brillouin zone. But the term 'Surface Brillouin zone' seems ambiguous; it is used in many papers, including Wan et. al. (2011) in the classic paper first describing Weyl semimetals, but nowhere does it seem to be well-defined.
Does it just refer to the projection of the 3D Brillouin zone along an arb... |
This is a practical question which I am trying to determine the life of 5 rubber pucks which act as suspensions/shock absorbers for my airplane.
Essentially 5 rubber pucks are stacked on each other with the weight of the front of the plane on top (in a static system) between the body of the plane and the front wheel.
N... |
Let's say a bullet of a 50 bmg with a speed of 4000 ft/sec = 1219.2 m/s lands right next to you.
About 1 second later, you hear the sound of the shooting.
The speed of sound in dry air at 20 °C = 343 m/s.
Knowing these facts, what is the distance of the shooter from you?
This is not a homework exercise, just something ... |
Suppose you collide two particles and produce a new unstable one.
Does its decay length (i.e. the distance it will travel) depend on the COM energy at which it is produced? assuming that the COM energy is larger than it's mass
|
Does an open system, like a glass with water inside exposed to the atmosphere, have walls? Can an open system be said to have walls?, if we can say that an open system has walls, can its walls be classified as rigid or mobile or with another type of classification? Or, in this type of system (open system), does the con... |
I have a irradiance reading from an LED which does not seem to make sense. I was hoping someone could shed alittle light on the issue.
The LED is question has a relative radiant intensity which follows a cosine law. I therefore assume the LED can be considered a Lambertian emitter.
As such, for a Lambertian emitter rad... |
I'm having some trouble with the following question:
A river has width a and floats on the latitude θ on Earth with the speed v. Due to the Coriolis force, the water surface will tilt. How much height difference h will it be between the two beaches? (The Coriolis acceleration can be assumed much smaller than the gravit... |
I am confused about a key step in Gherghetta's "TASI Lectures on a Holographic View of Beyond the Standard Model Physics" in the derivation of the holographic self-energy in the strongly coupled dual to a 5D scalar field in a slice of AdS.
The metric is:
$$ds^2= e^{-2ky}\eta_{\mu\nu} dx^\mu dx^\nu + dy^2$$ with $\eta ... |
I've seen some variations of this question on the forum, but none has satisfactorily cleared up my confusion, so I made this post with information about what I take issue with specifically. Thank you!
For simplicity, let's neglect atmospheric pressure. Consider a cylinder object submerged underwater (picture below). T... |
I recently took a course that discussed the WKB approximation for linear potential. In class and in the exercises we only looked at pretty simple potentials that are just a constant times |x|. What I tried to do I see if I could solve a potential like:
$$V(x)=\begin{cases}
0& x<-a \\
-a+|x|& -a\leq x\leq a\\
0 & x ... |
I'm trying to understand what's the physical meaning behind Pauli Exclusion Principle, why can't two electrons in the same orbital have the same quantum numbers? In particular, why do they have to have different spins?
I understand that the spin creates a magnetic field but I don't see why the magnetic fields would hav... |
I have noticed that if we play with the formula a bit, we get
\begin{align}
v^2 &= v_0^2 + 2a \Delta x \\
\frac{(v+v_0)}{2} \cdot (v-v_0) &= a \Delta x \\
\overline{v} \cdot \Delta v &= a \Delta x
\end{align}
Meaning the average velocity $\overline{v}$ times the change in velocity $ \Delta v $ is equal to the (constan... |
I'm reading Neu's "Singular Perturbation in the Physical Sciences" and in problems 1.1 and 1.2 he defines systems that "have memory" as the the variant of the harmonic oscillator
$$
\int_0^\infty e^{-s}\ddot{x}(t-\epsilon s)ds + x(t) = 0.
$$
This doesn't seem to fit in the category o delayed equation since the delay is... |
Tidying up my old papers I came across my supersymmetry notes from the late 80s. I thought I'd reread them. They may be out of date now. I find the mathematics somewhat comprehensible but not the physical discussion. (Roughly speaking I was a pure mathematician who took courses in QFT and Strings.) Here's a section:
T... |
I am currently trying to understand how to derive the commutation relations for the generators of the Poincaré group. What I am reading instructs to start with:
$$U( \Lambda, a) = e^{\frac{i}{2} \epsilon_{\mu \nu} M^{\mu \nu}} e^{i a_{\mu} P^{\mu}} $$
And use the representation relations:
$$ U(\Lambda , a) U(\Lambda', ... |
I want to derive the inhomogeneous Maxwell's equations on curved space time from the principle of equivalence. I assume that for a specific space-time point there is a coordinate system $\xi^\alpha$ such that in that specific coordinate system the Maxwell's equations take their flat space time form:
$$ \frac{\partial F... |
At the particle physics level, what is responsible for the so called diffraction of light in optics thematic of general macroscopic physics ?
|
EDIT:
I'm making progress in understanding in the discussion in the comments so take also a look there to have a complete picture. I also realized that the use of the "reaction force" words in the diagram below is wrong, it's actually an electric force.
I'm analysing the system of two current carrying wires one of whic... |
In Frank van den Bosch's Theory of Galaxy Formation Lecture 6 Page 41 he says that
The stagnation of growth in pressureless matter perturbations during
radiation dominated era is known as the Meszaros effect
...
The Meszaros effect is simply a manifestation of the fact that the
Hubble drag term during the radiation do... |
Some time ago, I asked for a definition of thermodynamic reversibility without mentioning entropy, and a user came up with the following formal definition of a reversible process:
Definition:
Reversible process means that given the outside controllable mechanical, electrical, magnetic, chemical, etc., macroscopic para... |
A few questions bother me a lot when I read Griffith's book.
Are all associated Legendre functions $\{P_{\ell}^m(\cos \theta)\}$ complete for any function $f(\theta)$?
For the Hamiltonian of a Hydrogen atom, there are both bound states ($E<0$) and scattered states ($E>0$). If I only select all eigenfunctions of boun... |
Matrix elements of the interacting real scalar field $\varphi(x)$ differ from the matrix elements of the in-(scalar) fields (which follow the free Klein-Gordon equation and are the asymptotic fields at infinity) by (Bjorken & Drell shortly B & D, the tags are also B&D ):
$$\langle 0| \varphi(x)|p\rangle=\sqrt{Z}\langle... |
as the title says, how does a battery use V = IR in measuring the intensity it would give, or is the voltage the variable here? if it's the voltage, what does that even mean?
|
In all books and texts I've seen so far, Newton's Second Law is used to prove that the net torque acting upon a system of particles with respect to its center of mass is equal to the rate of change of this system's angular momentum with respect to its center of mass. At this point, a crucial assumption is introduced: t... |
For jellium, the electron-electron interaction energy of a homogeneous electron gas is
$$V=\frac{e^2}{2\mathcal V}\sum_{\sigma\sigma'}\sum_{\mathbf q}\sum_{\mathbf k \mathbf k}\int\mathrm{d}^3\mathbf r\frac{e^{\mathrm i \mathbf q \cdot \mathbf r}}{r}\langle \mathrm G|a^\dagger_{\mathbf k-\mathbf q,\sigma}a^\dagger_{\ma... |
A central part of the Rayleigh-Jeans law is that the number of allowed states follows $dN \sim \nu ^{2} d\nu$ because the allowed frequencies have to be standing waves. Then by equipartition we get that the energy density in a given frequency band increases without bound for increasing $\nu$, which is obviously unphys... |
Could there be a charge different than that of a proton and that of an electron? Could there be a third type of charge that is not repulsed or attracted by either an electron's charge or a proton's charge? Maybe it would, however, be attracted by an opposite third kind of charge?
Note: Quarks still possess same type of... |
Recently, I have been interested in the scattering amplitudes of mesons in the high-energy fixed-angle regime. I have come across a simple result, due to Brodsky et al., that predicts the scaling of such amplitudes with Mandelstam variable $s$.
However, I have been wondering whether there exists actual experimental dat... |
The shape of the $s$ orbital is spherical. Consequently the $1s$ orbital will be a sphere with nucleus as its center while $2s$ will be a similar but bigger sphere.
Now orbitals represent the space in which the electron could be found. But we see that the spaces of $1s$ and $2s$ overlap. So does that mean that a $1s$ ... |
For a while now I've been researching the causes of why a fireplace fire makes a roaring sound, and from what I've read, it mostly has to do with the way air rises, creating a vacuum underneath, pulling cold air into it. These exchanges in air flow can disturb its surrounding environments, causing vibrations that we mi... |
So I am at an impasse regarding this.
Assume that there’s a source of sound moving towards a stationary observer. The source is accelerating uniformly.
Does the Doppler effect on the frequency recorded only depend on the speed of the source at the exact moment when the sound was emitted? Or does acceleration factor int... |
Question: *A big block of mass $2m$ is placed near a wall in such way that only its left side touches the vertical wall. Now a ball of mass $m$ is released from top (near to the side of the wall) of a smooth cylindrical groove of radius $R$ made inside the bigger block of mass $2m$, placed on a smooth frictionless floo... |
According to this resource from John Boccio:
Consider a body at rest on surface of Earth. Imagine that it shifts
about vertically ever so slightly. Because it has done so, it has
moved to a slightly higher or lower elevation, and so it has shifted
its gravitational potential energy which depends on height. This will
c... |
I've been reviewing the correspondence between Hooke and Newton, trying to understand how an object falls eastwards, as predicted by Galileo as well. I've read two things:
As an object falls, it retains its original tangential velocity as radius decreases. Since there is a discrepancy between $v_{object} = (R + H) \om... |
I'm not sure to understand what's is the perturbation Hamiltonian exactly.
It seems like in the case of the proton-electron the perturbation Hamiltonian is a correction of the potential energy, a term that we add to the potential where we consider the proton as a point and not a sphere. Am I correct ?
Is the perturbati... |
Consider a simple model:
A single photon of light in a vacuum travels from (-1,0) to (0,0) , where it hits a reflective point at the origin at time T.
CASE 1: Suppose the velocity of light follows a continuous curve (i.e. the plot of v VS t for this photon is a continuous curve).
Then, at t < T it was traveling at v=... |
Actually, this question was answered by Lawrence B. Crowell,
but I would like to explore this topic further.
Can anyone give me please references on where I can find it?
|
I have read this PSE post Finite Temperature Quantum Field Theory, saying that
In a QFT at finite temperature, we consider the Euclidean time to be periodic, i.e. we consider a theory on the manifold $\mathbb{R}^{d−1}×S^1$, where the spatial coordinates are in $\mathbb{R}^{d−1}$ and the time coordinate in $S^1$. The t... |
Do free electrons (plenty of them in space and in stars) scatter every photon they come across?
Free electrons, unlike those in atoms and molecules, don't have specific energy levels after all...
Isn't this what happened before the Era of Recombination and the release of the CMB? Every electron interacting with every ... |
In Griffith's Introduction to Quantum Mechanics, he said that " For unstable particle, that spontaneously disintegrates with a lifetime τ, the total probability of finding the particle somewhere should not be constant."
So, my question is, why disintegration of a particle leads to non constant value of probability, bec... |
In quantum mechanics, we can choose which basis in which to represent a system's state. A superposition state in one basis can be an eigenstate in another basis.
I was wondering if this is always true. I mean, if, for any given quantum system in any given state, there must exist some basis in which that state is an eig... |
As in the title, in the $\Lambda$CDM model, is the cosmological constant always interpreted as the vacuum energy contribution? Or is the origin left open?
If I say that "it is usually interpreted as the vacuum energy but its origin can also be a barotropic fluid with constant dark energy equation of state parameter" ... |
Soap film will not readily form a cylinder, instead, it will form a catenoid if it's circular faces are flat. I know that this happens to minimise surface area.
But how to prove that this provides the minimum surface area?
Is there an expression to calculate the radius of curvature of the curved surface, and to calcula... |
The mathematical representation of the net external force on a system is $\vec F_{net} = \frac {d\vec P}{dt}$, which is the rate of change of linear momentum of the system. If we substitute $\vec P = m\vec v$ into the formula for force and differentiate, we get:$$\vec F_{net} = m\frac{d\vec v}{dt} + \frac {dm}{dt}\vec ... |
In Schottentloher's book, a theorem is stated:
Later on, a remark is made:
My confusion comes: Is E always of the form made in the remark, namely are the following to sets equal(up to set theoretic iso)?:
\begin{equation}
\{(U,g) \in U(\mathbb{H}) \times G \,:\;\; \hat{\gamma} (U)=Tg\}=U(1) \times_{\omega} G
\end{equ... |
I am struggling with a physics question that involves a ladder leaning against a wall. I have attempted to solve the problem, but I am not confident in my answer.
The question is as follows:
"A ladder is leaning against a wall. The angle between the wall and the ladder is $0<\theta<90^{\circ}$. The friction between the... |
Let a point P exist just above the surface of a glass slab of thickness $L$.
Light is incident vertically on this slab. The light at point P, at some instant has phase angle $\phi$.
The refracted light will travel a total path of $L + L$ before again reaching the upper surface just below P. It takes time $T = 2L/c$ for... |
In this question, I want to restrict the discussion to classical mechanics as understood before 1900; that is, to exclude any discussion of relativity (however, if there is a neat generalization I would be eager to hear about it).
As I go back and reread a classical mechanics textbook, I am again struck by how opaque s... |
In static spherically symmetric spacetime with metric $$ds^2=e^{2\nu}c^2dt^2-e^{2\lambda} dr^2-r^2 (d\theta^2+\sin{\theta}~d\phi^2)\equiv \delta_1~c^2 d\tau^2 \tag{1}$$ the geodesic equation in equatorial plane ($\theta=\pi/2$) reads $${e}^{2\nu+2\lambda}~\frac{\dot{r}^2}{c^2}=k^2-{e}^{2\nu}~(\delta_{1}+\frac{l^2}{c^2 ... |
When light is reflected from an object, the wavelength of the reflected light represents the colour of the surface of the object. How are other properties of the surface, such as shininess, represented?
|
I've just learned about redshift a couple of days ago, and i found myself questioning why relative motion to the observer is the only thing that could affect the intensity of the red shift of the frequencies of electromagnetic waves. Can't temperature cause blue shift as photons are more energetic causing them to oscil... |
My question pertains to the relationship between acceleration (change in speed and/or direction of motion) and time dilation. Since acceleration (we'll consider change in speed) involves motion, and since motion itself is relative, why does time dilation due to acceleration occur for only one of the two frames we are c... |
This is a really simple question that I fail to quickly find and answer for.
The metric signature for Minkowski space or more general Pseudo-Riemannian manifolds is usually denoted by a list of signs or something similar, for instance the mostly-plus convention would be given with the statement
$$
\eta_{\mu\nu} = \math... |
Reference: minutes 2:50 to 3:15 in the following video
https://www.youtube.com/watch?v=Km6kqykX900&t=170s
I don't understand how the atomic number goes up by 1 in two decay steps. Is there a neutron decay in both the stages or is something more complicated going on?
|
Imagine a vibration generator is attached to a stretched string. Will the frequency of the vibration generator be equal to the frequency of the waves produced in the stretched string?
Also, a similar follow up question, imagine I have a tuning fork of a specific frequency forming sound waves in an air column. Will the ... |
What does superposition actually mean? Can something like an atom actually be in two different states at once or do we just not know which state it is in? Also, how can our act of observing something force it to "decide" (whatever that means) which state it is in? What controls this randomness?
|
This is not homework, just a home project that I'm working on - although I'd like to get to the end result myself.
I'm familiar with Bernoulli's and Navier-stokes equations, it's just been a while and I'm struggling to find good reference material.
The project is a heat exchanger.
A compressible fluid, at 'x' °C, is fo... |
I was wondering that why does the equivalent resistance actually increase in a series connection of resistors and why does it actually decrease in a parallel connection of resistors?
I know that we can prove it by the formula $V/I = R$ but what's actually the reason behind it.
The current remains the same in series con... |
How do we combine kinetic and gravitational time dilations. Lets say that a fast rocket experiencing 5% kinetic time dilation passes near a black hole in a region of 10% gravitational time dilation. When viewed by a distant observer, does the rocket have a total of 5 + 10 = 15% time dilation? Or is it 1.05 x 1.10 = 1... |
Suppose, there is a system of charged particles interacting via a pairwise additive potential and in the presence of a position dependent external potential and an external magnetic field. The Hamiltonian of the system can be written as :
$$H = \sum_{i=1}^{N}\frac{(p_i-qA_i)^2}{2m}+\sum_{i=1}^{N-1}\sum_{j=i+1}^{N} V(|... |
In four dimensions Lie superalgebras naturally arise by relaxing the presupposition in the Coleman-Mandula theorem that the symmetry is not classified by a Lie algebra. It is then typically stated that the spin-statistics theorem requires the newly allowed generators to form half-integer spin representations of the Po... |
If we suppose a $\varphi^3$-theory diagram of self-correction or $\varphi^4$-theory diagram of scattering we encounter an integral
$$\int\frac{d^4q}{(q^2-m^2)((p-q)^2-m^2)}.$$
I have no idea, how to solve it and it also seems to be divergent
If we consider $\varphi^4$ self-correction we get an even more complicated int... |
How can I find/obtain irreducible representations of spin point groups?
Spin point groups are point groups in combination with spin rotation operations. For example, the magnetic point group 2/m belongs to spin point group with the following elements:
{E||E,E||i,C2||m,C2||C2}, here elements before || acts only on spin ... |
I'm confused about tetrad formalism.
In the article the have the Kerr metric in Boyler-Lindquist coordinates. They then define the tetrad at a point $r,t,\theta,\varphi$ as the one-form basis
$$
e^{(t)} = \left(\frac{\Sigma \Delta}{A}\right)^{1/2} dt
$$
$$
e^{(r)} = \left(\frac{\Delta}{\Sigma}\right)^{1/2} dr
$$
$$
e^{... |
Hope you're ready for a long question, but I think quite an interesting one!
One-pion exchange is an established nucleon-nucleon potential which is well-defined for any joint angular momentum state of the two nucleons. A full derivation may be found for example here, but the essential idea is that one combines two copi... |
Given an atomic nuclei say C-14 or U-233 or anything in-between or outside the range and given the ratio of protons and neutrons in the nuclei, is there a comprehensive equation or set of equations that can model the strong nuclear force and binding energy of the nuclei, to predict the following:
Whether the nuclei fa... |
What does the $\gamma$$c$ term in the temporal component of the 4-velocity equation represent exactly? Moreover, what does it mean conceptually when the velocity term in the gamma function is equal to the speed of light or say even 99.9999999% the speed of light in $\gamma$$c$? $$\frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}c$$... |
Imagine, we have an air column and the the temperature of the air was the same outside and inside the column. If sound waves from a tuning fork then enters the air column, the speed of the standing wave would have to be the same as the waves outside the pipe as well. We know, that for a STANDING WAVE, its wavelength is... |
I'm reading a publication and trying to understand a simple part that has me caught up:
Equations for the field inside and outside a longitudinally magnetized, finite cylinder were first retrieved by Callaghan and Maslen. They obtained their result by considering a finite cylinder as a collection of current loops (i.e... |
I read an article.
When an object is travelling near speed of light, it's mass increase.
The article argues while the inertia increased, that is, the object will be harder to speed up, the gravitational effect doesn't increase. The gravitational effect is always the same with the rest mass of the object.
If that's the ... |
I have a particular question with respect to renormalized operators of $\phi^4$ theory, namely the mass operator $\phi^2$ but at two-loop order. With respect to Peskin and Schroeder's text, chapter 12, the normalization is given by equation 12.113 while the first loop correction is equation 12.114, repeated here for cl... |
The unit of loudness is $$\rm\frac{W}{m^2},$$ which is equivalent to $$\rm\frac{kg}{s^3}.$$ Since kg is the SI unit for mass and s is the SI unit for time, this led me to the following question:
Can the loudness be defined as the mass of a body divided by the cube of time?
|
Why experimental tools like Raman scattering, Inelastic neutron scattering (INS), Resonant inelastic X-ray scattering (RIXS), etc., can only detect bosonic excitation?
Why electronic excitation won't involve in these processes?
Its common feature is that they are photon-in photon-out spectroscopic techniques. But I sti... |
This is a follow-up question on a question I previously asked, namely Coherent states and thermal properties. The authors of the article I am referring to in the previous question (Thermodynamics of Coherent States and Black Hole Entropy), after deriving an expression for some sort of temperature in coherent states in ... |
The labs at CERN create anti-Protons, and have collided them with Protons. Anti-Hydrogen is used to study matter-antimatter asymmetry.
Were there any attempts to collide anti-Protons with anti-Protons? It seems like a direct way to study this asymmetry, and there is ample reference measurements from Proton-Proton colli... |
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