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In my textbook, it states that when a parallel-plate capacitor is connected to a battery, charge will flow from the battery onto both plates. How is this possible since current only flows from one end of the battery. Also since the plates are separated the charges don't flow from one plate to another like they normally... |
In a photon BEC, people are talking that cavity consisting of $2$ highly reflective mirrors make the photon gas $2$ dimensional by freezing out one wavevector $k_z$, which stays constant:
$$
k_z=n\pi/L
$$
where $L$ is cavity length and $n=7$. What does $2$ dimensional photon gas mean then? It means that photons then ca... |
We know that Electric field or electric force acts on charges at rest and magnetic force acts on charges in motion. But when we combine these two we get what we call as Lorentz force. So I want to know that how can these two forces act on the same charge. Either it should be that E.F acts on the charge (if at rest) or ... |
It seems possible to detect a single photon.[1, 2]
But the photon is a free particle. Its momentum is decided precisely and it means that the position of the photon is uncertain. The photon can exist everywhere and the probability of detecting a photon at the finite region would be zero. To detect the photon, we would ... |
My professor made following statement:
The spacetime of GR is curved in the presence of strong gravitational fields. The effects of curvature
manifest themselves at large distances. Locally, one can choose a flat Minkowskian metric.
I dont get it:
I thought, gravitation is expressed by c... |
Although there's equal and opposite reaction, usually the force is not balanced
Can you explain why?
|
Update: may have figured it out (below)
I've been reading Preskill's notes on vortices, and he's included a couple of exercises at the end of section 1.3.
In the first, you must look at the breaking of $G = SU(2)_1\times SU(2)_2 \times U(1)_Y$ down to $H = U(1)_Q$ where $U(1)_Q$ is generated by
$Q = p T_3^{(1)} + q T_3... |
Why to find e.g. the total energy of a system of particles (non-interacting) we add their individual kinetic energies? Is total kinetic energy defined to be that sum? It may seem obvious for scalar quantities like energy but what if we consider vectors? For example the total momentum of a system of particles is their v... |
I am confused with this question.What Gaussian surface do I take to calculate the electric field at the $q$ charge? Should it be a cylinder containing the whole system? Or should it be a cylindrical surface inside the bigger cylinder? If yes then why is the bigger cylinder not included? Please help
|
Suppose there's a loop of current carrying wire in a plane,then it's stated in my book that magnetic flux through the area of loop will be negative and of equal magnitude as the flux outside the loop and in the plane.The reason given is supposedly following gauss law, "since magnetic field lines are closed loops each f... |
The uncertainty principle states that there always will be mean variance if we measure position or momentum. It does not state that the measurement is wrong. It only states that there always will be a deviation from the mean value of position/momentum or $<x>,<p>$. The closer the position measurement is to the mean, ... |
Hello im studying special relativity and i was wondering something about length contraction. Let's say someone who is not moving is seeing a rod which has one edge at $x=0$ and the other at $x=a$ so its length is $a$. An observer moving at constant speed $u$ along the $x$-axis uses lorentz transformation to determine t... |
I am confused by conjugation, and the action of group elements on themselves. If I have a rotation acting on the generators of $su(2)$, i.e.
\begin{align}
R_\theta (L_1, L_2, L_3)
\end{align}
where $R_\theta$ is some rotation matrix. The elements of the vector $(L_1, L_2, L_3)$ are themselves the $su(2)$ generators, in... |
I am asked to write a detailed Hamiltonian function for a particle moving in a central potential using spherical coordinates. It feels like i got it right, but I'm not sure if it's "detailed" enough. Can someone please check it?
My progress:
Lagrangian:
$$L = T - V = \frac m {2}(\dot{r^2} + r^2 \dot{\theta^2} + r sin... |
I am trying to solve the following:
$$\frac{\partial^2u}{\partial x^2}-3\frac{\partial u}{\partial t}=-9$$
$$u(0,t)=0=u(\pi,t)$$
$$u(x,0)=0$$
So solving the homogenous case first by separation of variables $u(x,t)=X(x)T(t)$ to get the eigenvalue. Substituting and dividing by XT we get:
$$\frac{\ddot X}{X}-3\frac{\dot T... |
Given that if you make two observations of an electron's position in quick succession, the electron will be in the same place. Is there a time frame for how long it will stay in the same position (possibly some multiple of Planck time) and if so, would the wave function spread out again from the observed place or from ... |
On a playground swing, children quickly learn how to swing higher and higher by timing their body motions with the resonant frequency of the swingset. But it occurs to me that it seems you're making something out of nothing, creating motion without anything to push against.
It can't be the air, because if you assume a ... |
Studying Special Relativity we discover that Maxwell's Equations can be also written in the following way:
$$\partial _\mu F^{\mu\nu}=\mu_0J^\nu$$
$$dF=0$$
Where: $F$ is the Electromagnetic Tensor, $J$ is the Four-Current Density and $dF$ to my understanding is simply a shortcut to write:
$$\partial _\lambda F_{\mu\nu}... |
There are some mistakes I think in the figure of Wikipedia on particle interactions in standard model: https://en.wikipedia.org/wiki/Mathematical_formulation_of_the_Standard_Model#Alternative_presentations_of_the_fields
It is more precise if we represent the particles in terms of left-handed doublet or right-handed si... |
I'm reading along with Hehl, von der Heyde, and Kerlick's General relativity with spin and torsion on gauging the Poincaré group to include spin into GR.
They introduce the covariant derivative
$$D_\gamma = e^i_{\;\gamma}D_i = e^i_{\;\gamma}\left(\partial_i + \Gamma_i^{\;\alpha\beta}f_{\beta\alpha}\right)$$
where $e^i_... |
Say I have a two-state system $|\psi \rangle=c_1|0\rangle+c_2|1\rangle$. If the states $|0\rangle$ and $|1\rangle$ are orthogonal, then the probability is:
$$
\begin{align}
\langle \psi |\psi \rangle&=(\langle 0|c_1^* + \langle 1|c_2^* )(c_1|0\rangle+c_2|1\rangle)\\
&=c_1^*c_1\langle 0|0\rangle+c_2c_2^*\langle 1|1\rang... |
I am trying to compute the matrix elements
\begin{equation}
\langle j \, m | a_{1}^{+} | j' \, m'\rangle
\end{equation}
\begin{equation}
\langle j \, m | a_{2}^{+} | j' \, m'\rangle
\end{equation}
using Wigner–Eckart theorem
. I started by defining Schwinger representation angular momentum as following
\begin{equation}... |
A related post could be found here: https://physics.stackexchange.com/a/35468/209383
I came across this picture. I looked up an explanation from the above post for the "rays" of diffraction. However, it occurred to me that the pictures of those rays were all of light sources (or reflections), i.e. in the picture below,... |
The concepts of correlation and order are ubiquitous in statistical physics and condensed matter but I have yet to find a reference that makes an order in the confusing terminology.
As far as I understand now -
Long/short/quasi-long range order:-
LRO: $$\left<\sigma(x)\sigma(y)\right>\overset{|x-y|r\rightarrow\infty}{... |
Lacking a Lensmeter,
if I am to confirm that a lens has diopter +2.50,
I might seek a reference lens (one that I know is +2.50) and position both away from a sheet of paper in plain sunlight, then confirm that the focal distance is the same.
How do I do the same with a lens that is -2.50, perhaps even without having an... |
In Zee's QFT in Nutshell book p/410, he uses the following method to show $U(1)$ electric charge of proton + electron $$Q_e+Q_p=0$$ in Grand Unified Theory (GUT):
However, Zee only shows
by the traceless properties of ${\bf 5}$ in $SU(5)$:
$$3Q_{\bar{d}}+Q_e+Q_{\nu_e}=0$$
This means the sum of the charges of eq.11 i... |
We said that the EM and weak interactions are unified as Electroweak Unification. However, for usual Grand Unification, it requires that the gauge group G is simple Lie group -- which means the G has no nontrivial normal subgroup other than itself.
However, neither $U(1) \times SU(2)$ nor $U(2)$ are simple Lie groups... |
I know this question has been asked twice before, but i didnt find any satisfying answer there.
I learnt in my class that the energy stored in the capacitor per unit volume comes out to be
$\dfrac{\mathrm{d} U}{\mathrm{d} V} = (1/2)\epsilon E^{2}$
our teacher then said this is a general statement and is true for every ... |
I really don't get how this function for calculating the Y of a sine wave based on a particular point in the X-axis and time works.
$$f(x, t) = A\sin(kx-wt+p)$$
$x=$ position on X-axis
$t=$ point in time
$a=$ amplitude
$k=$ wave number
w=angular frequency
p=phase
I'm writing down all of the letter meanings mostly as a ... |
I've heard that the time reparametrization invariance in GR can be thought of as a gauge symmetry. Could someone specifically explain how, while also explaining if there is any connection with the dimensions of space-time and whether (or not) such a symmetry would give rise to a conserved current?
|
I'm trying to formulate mathematical model of a nut on screw dynamics. Let's consider nut (with inertia $I_n$ and mass $m_n$) on a screw (with inertia $I_s$) - both rotating with constant angular velocity $\omega_0$ about the vertical axis ($y$). The rotational angular velocity of the nut about the screw frame is equal... |
I read that homogenous space implies conservation of momentum (according to Noether's theorem) Conservation of momentum is kinda the statement that bodies continue moving with constant velocity unless a force is applied.
Suppose we instead lived in a universe where a bunch of frames could be described as absolutely at ... |
Consider an arbitrary connection $\Gamma$, compatible with the metric, in 4 dimensional spacetime:
$$\nabla_{\lambda} \, g_{\mu \nu} \equiv \partial_{\lambda} \, g_{\mu \nu} - \Gamma_{\lambda \mu}^{\kappa}\, g_{\kappa \nu} - \Gamma_{\lambda \nu}^{\kappa} \, g_{\mu \kappa} = 0. \tag{1}$$
I don't assume symetry of that c... |
If mass merely 'curves' spacetime, why do photons follow the geodesic path of the gravitational field (path A) instead of the spacetime curvature itself (path B)?
It seems, as if, the gravitational field exerts a continuous pull of the space-time continuum, not a mere bend.
Given we are defining a behavior from an exte... |
It seems that most people agree to the field inside a hollow cylinder being zero but I’m troubled when I consider the case of a ring shaped linear distribution of charge.
It is known that the electric field due to a ring charge distribution inside it(in the plane) is non zero (don’t take my word for it, https://youtu.b... |
It is well-known that time reversal operation is implemented as an anti-unitary operator. I wonder what are some other examples of anti-unitary operators that appear in the context of quantum mechanics, or physics in general.
|
I have been reading Senechal's lecture notes on bosonization, and I appreciate the care that he takes in dealing with the zero modes of the massless boson. However, when it comes to applications - e.g. the Tomonaga-Luttinger model - it seems that all these nuances about zero modes and boundary conditions get thrown out... |
In L. Fu and Kane's paper they that spinless px+ipy wave superconductor can emerge from s wave superconductor + topological insulator heterojunction,But my result is not the same as their paper.Could you figure out my mistake in derivation.
The hamiltonian of 2D TI:
$$H_{0}=\psi^{\dagger}\left[ v\sigma_{x} p_{x} + v\s... |
A $4$ kg object is moving in one dimension along the x-axis. The linear momentum of the object increases with the position of the object according to the following equation:
$p(x)=6+3x$
At $t = 0$ s the object is at $x = 0$ m. Where is the object (in m) at $t = 4$ s?
we have $$6+3x=4(dx/dt)$$ and then $$(6+3x)dt=4dx$... |
In Zee QFT in a nutshell book p.418, Zee said about Quark mass vs Lepton mass $m_d/m_e$
:
He first mentioned $m_d/m_e=1$ for unification scale.
Then he mentioned $m_d/m_e\sim 3 $ in eq.15.
Are these two facts contradicting each other? Generally, what can one say about the Quark mass vs Lepton mass in GUT or for uni... |
If in general the specific heat capacity is low in gas then why doesn't it raise it's temperature more quickly compared to a solid that is given similar conditions as to the gas. (By the reason of the definition of s.h.c. is "heat that should be transferred in order to change an unit temperature in 1 kg" )if so then b... |
Kindly give me the explanation of this numerical which says A ball of mass $0.2$ kg is thrown vertically upwards by applying a force by hand. If the hand moves $0.2$ m while applying the force and the ball goes upto $2$ m height further , find the magnitude of the force . $g=10\ ms^{-2}$.
The answer in my textbook is $... |
I saw a video of Walter Lewin on YouTube in which he was showing a demonstration on Capacitors. In this demonstration, he gives a charge to the Capacitor, dissembles it and reconstructs the Capacitor. But after removing the charges also, the Capacitor still holds a potential difference. How is that possible?
The video
... |
When a proton and electron combine to form Hydrogen gas after the big bang, would the wave function of the electron collapse as they bond together?
|
In general theory of relativity the Einstein field equations e.g. relate the geometry of space-time with the distribution of one body within it.
$$R_{\mu\nu}-\dfrac{1}{2}g_{\mu\nu}R+g_{\mu\nu}\Lambda=\dfrac{8\pi G}{c^4}T_{\mu\nu}.$$
What will be the "Einstein field equations" for two or three bodies?
|
Why do we use energy conservation to obtain maximum displacement of the block in spring block system whereas for displacement of the mean position(equilibrium position) we use $F_{net} = 0$ on the block?
The below image describes the actual problem
|
In a system one is analysing for superconductivity signatures, what are possible experimental (optical/microscopic/spectroscopic) observables for identifying and differentiating superconductivity?
|
I am looking for:
a general definition of collective mode appearing often in condensed matter.
concrete examples of collective modes.
I have some ideas in my mind but I wish I could compare it with a clear text-book-like description.
|
The time evolution of a point in phase space in classical mechanics can be described as
\begin{equation}\label{eq:TmeShift}
( q_i(t + \Delta t),p_i(t + \Delta t) ) = \left( 1 - i\Delta t \hat{L}\right) (q_i(t),p_i(t) ),
\end{equation}
where $\Delta t$ - infinitesimal time shift, $\hat{L}$ - Liuouvillian, given as
\b... |
Why are axions considered cold dark matter? They have a very low mass and if I'm not wrong they decouple before BBN, and in some models even earlier than neutrinos, they they should definitely be relativistic at the moment of decoupling and therefore Hot dark matter.
So why aren't they cold dark matter?
|
In cubic crystals where $a=b=c$, there are rotational invariances that leave the system unchanged. If some of the electrons are responsible for many properties of solids and that they are free to move (like in a good metal), it makes no difference if one applies a current along any of the crystallographic axis, I get t... |
Between two stationary charges, Newton's third law holds. But what if one of the charge is moving? Like, in moving charge, electric field is different with the field generated by stationary charge.
So let's think there are two charges. Charge with $q_1$ moves toward to another charge with $q_2$, that is stationary. Th... |
I'm looking for any (non-trivial*) time-independent Hamiltonian expressed in the Pauli basis (with analytically known real coefficients), which unitary time evolves some analytic initial state to some analytic future state. That is, a system for which I can write down the time-evolved state without performing numerics,... |
If you take an amperian loop then, how do we find the direction of dl vector at different points on the loop?
|
generally we integrate out the heavy field/modes in effective field theory, however, I'm wondering why couldn't we integrate out the light field/modes instead. Actually i think it's reasonable from mathematics.
|
A source emits sound of frequency $f$ and speed of sound in the medium(here, air) is $330 m/s$. If the source acquires a velocity ‘v’ w.r.t. the medium, what is the wavelength of sound emitted from the source in the direction of its motion?
My approach to this question first brings a question:-
Will the speed of the e... |
This question is related to symmetry properties of the Lagrangian and conservation laws. Let us consider a one-dimensional case of a particle of mass $m$ moving along the $x$ axis such that the Lagrangian is given by $L = \frac{1}{2} m \dot{x}^2 $. Now, if there is an active coordinate transformation such that the phys... |
I am a bit confused and need a well rounded explanation.
Have a look at two scenarios:
A metal plate with small scratches on it appears diffuse in the optical spectrum, because the roughness reflects the light in different directions. In the infrared you don't see these scratches, because they are much smaller than th... |
I am studying the observability properties of a dynamical system and I get to the next equations:
$$x(t) \in \mathbb{R}^{n}$$
$$A(t) \in \mathbb{R}^{n\times n}$$
$$\Phi(t,t_{0}) \in \mathbb{R}^{n\times n}$$
$$$$
$$\dot{x}(t) = A(t)x(t) \hspace{1cm} x(t=0) = x_{0}$$
$$\frac{d\Phi(t,t_{0})}{dt} = A(t)\Phi(t,t_{0}) \hspac... |
As all the molecules in the lattice are vibrating together to form a wave and the phonon is a quantum phenomenon, it makes sense to me that all the molecules inside the lattice are in the entangled state which is changing with time like propagating wave.
But it's hard to believe that so many molecules (which are in the... |
As defined in the literature, discrete-time quantum walks use an extra coin space to decide in which direction to move.
To get an idea consider this classical example: Assume the walker on an integer line at 0 with a coin in his hands. The classical random walk proceeds as follows. He tosses the coin and depending on h... |
I read all the suggested duplicates and they seem to be addressing the relation between primary colours and VIBGYOR. But my straightforward question is when so many colours with different wavelengths exist, why only 7 are special. And secondly when we say that Newton showed white light is made of 7 colours, what does i... |
So I was just reading about satellites burning up in the atmosphere. The book pointed out that it wasn't the gravitational velocity (towards the earth) that caused objects to burn up (which makes sense since the thinner air means less air friction which balances out the increase in terminal velocity [at a guess]), but ... |
I am an absolute amateur in physics but some questions haunt us all, don't they?
In some places I hear/read that the conscious observer changes the pattern (https://youtu.be/XDpurdHKpb8?t=1559). In other places, it is explicitly stated that "it is necessary to have a conscious observer - just a detector/measuring devic... |
My question is somewhat related to this one: Expectation value for spherically symmetric states
In the case of the hydrogen atom, we have that in the ground state the following expectation value vanishes,
\begin{equation}
\left\langle\phi(\vec{r})\left|\left(\frac{3r^ir^j}{r^5}-\frac{\delta^{ij}}{r^3}\right)\right|\phi... |
The impulse operator in quantum mechanics is given by
\begin{align}
\hat{p} = \frac{\hbar}{i}\nabla
\end{align}
As a Hermitian operator, the expected value of this operator $\langle{p}\rangle = \langle \psi|\hat{p}\psi\rangle$ should be real. However, for a real wave function $\psi(\vec
{r})\in \mathbb{R}$ (a valid sol... |
In the below figure,
A rigid rod is at rest. End point $A$ and $B$ are at $x=0$ and $x=1$ respectively.
At $T=0$, in an instant $A$ starts moving at velocity $+v$. i.e. coordinate of this event i.e. A starts moving is $(0,0)$
Question: What is the $(x,t)$ coordinate when $B$ starts moving.
Let us assume answer is $(x_... |
First, let's say I have a classical system involving throwing a fair coin. There are two possible events $\{\text{head},\text{tails}\}$. Their respective probabilities are:
$$
P(\text{head})=\frac{1}{2}\\
P(\text{tails})=\frac{1}{2}\\
P(\text{head})+P(\text{tails})=1
$$
In a quantum system scenario, the probabilities a... |
Sorry if this question has been asked already but after researching I have found that quark flavour is not changed in the strong interaction. This confused me because how can a down and anti down quark both change flavour to a strange and antistrange quark in diagram below?
|
I'm currently going through Matthew D. Schwartz book Quantum Field Theory and the Standard Model, p. 23. For free (non interacting) field theories we are able to quantise the field by expanding our field operator as a Fourier transform of ladder operators for each mode, i.e.
$$\phi_0(x) = \int \frac{d^3p}{(2\pi)^3} \fr... |
Does the process of decaying in radioactive elements occur every second?
The equation consists of $\rm e$, so it must mean that decay due to radiation must occur every second, right?
|
Today I left my detachable shower head on the floor and as soon as I turned the water on, the shower head started moving and getting jumpy.
Onto my question- why do hose pipes move and jump when water is flowing through them? I have noticed that usually this effect (I'm such a noob that I don't even know what it's call... |
Every answer explaining decoherence brings up the concept of phase relationships, but I'm just not seeing the connection. In the double slit experiment, for example, it makes some intuitive sense to me that the surroundings would interact with different parts of the electron's wave-function differently, effectively cre... |
I am reading material related to statistical physics, and I am having a problem understanding why we care about the notions of distinguishably and indistinguishability. I have found What are distinguishable and indistinguishable particles in statistical mechanics? on here, but it doesn't answer my question since it doe... |
The article about gauge theory on Wikipedia contains the sentence "Lie group". How can we prove that the gauge transformations that are given in an article form a Lie group?
I give you an example. Consider time reparametrisation. $t$ is replaced by $\tau$ and $x$ by $x'$ with
$$x'(\tau) = x(t)$$ so we have a set of fu... |
This question is asking to better understand the semantics of mainstream physics. My assumption being there is a specific narrative behind the preferred term. In any case, it seems like an essential topic of mainstream physics worth of reflection.
Given we do not know what gravity "is" in any fundamental way, and we ar... |
My post here is to question the magical notions about the Relativity theory. There seems to be one major historic misconception in the Relativistic interpretation, commonly believed and understood to be true. [Part of the flaw stems out from the Michelson-Morley experiment, where the speed of light 'c' is measured from... |
I'm trying to code a game that uses physics...but I don't how to figure something out:
If I have a 2x2 square (in any unit), with two thrusters/jets whatever you want to call it, on the back, each 1x1 in size...
_ _
|_|_| <-- 2 1x1 Squares
|_|_| <-- Other 2 1x1 Squares
| | | <-- 2 Thrusters
if I turn both of the th... |
Consider the following generic equation for a damped oscillator (eq 5.33 in Taylor's CM book)
$$
x(t) = e^{-\beta t} \bigg(C_1 e^{\sqrt{\beta^2-\omega_0^2}t} + C_2 e^{-\sqrt{\beta^2-\omega_0^2}t}\bigg)
$$
derived from (5.24 and 5.28)
$$
m\ddot{x} + b \dot{x} + kx =0
$$
$$
\ddot{x} + 2\beta \dot{x} + \omega_0^2x =0
$$
... |
I want to find a book that teaches simple Kinematics problems but use both Newtonian and Analytical method, and maybe draw parallel between them. Is there such a reference?
|
Thermal expansion coefficient is defined as:
\begin{equation}
\alpha=\frac{1}{V}\left(\frac{\partial V}{\partial T}\right)_p
\end{equation}
We can prove through the third law of thermodynamics that:
\begin{equation}
\lim_{T\to0}\alpha=0
\end{equation}
Now, consider ideal gases equation:
\begin{equation}
pV=nRT\implies ... |
In polar coordinates, we can write:
$$\frac{d^2\vec{r}}{dt^2}=\frac{-GM}{r^2}\hat{r}=(2\dot{r}\dot{\theta}+r\ddot{\theta})\hat{\theta}+(\ddot{r}-r\dot{\theta}^2)\hat{r}$$
$$\frac{-GM}{r^2}=\ddot{r}-r\dot{\theta}^2\tag{1}$$
$$0=2\dot{r}\dot{\theta}+r\ddot{\theta}\tag{2}$$
We also know that $h=r^2\dot{\theta}$ is a con... |
I would like to compute what the constant acceleration trajectories are in the Minkowski spacetime $(t, x)$ with $d\tau^2 = dt^2 - dx^2$. So given some trajectory $x(t)$ I know the velocity vector is given by
$$U = \left( \frac{dt}{d\tau}, \frac{dx}{d\tau} \right)$$
In the previous version of this post I made some grea... |
In many books on nonlinear fiber optics, the Taylor series expansion of the mode-propagation constant $\beta$ is performed about a frequency $\omega_0$ at which a pulse's spectrum is to be centered.
$\beta(\omega) = n(\omega)\frac{\omega}{c} = \beta_0 + \beta_1(\omega - \omega_0) + \frac{1}{2}\beta_2(\omega - \omega_0)... |
If I have a theory with a $2 \times 2$ matrix $\Phi$ of scalars that transforms under a gauge group $SU(2)_L \times SU(2)_R$ as $\Phi \rightarrow U_L \Phi U_R^{\dagger}$, how does $\Phi$ transform under an $SU(2)_{L+R}$ group generated by the sum of the generators of $SU(2)_L$ and $SU(2)_R$?
|
The planck length is considered by many to be a lower bound of the scale where new physics should appear to account for quantum gravity.
The reasoning behind, as far as I understand, is that $l_{P}=\sqrt{\dfrac{\hbar G}{c^3}}$ consists of the fundamental constants of gravity and relativistic quantum mechanics.
By the s... |
This chart
http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/alptun.html#c1
indicates that lower energy alpha particles have much longer half-lives. I am interpreting 'energy' to be a calculation based on the mass of an alpha particle and its velocity. So another way to read that graph might be to say that faster movi... |
Although we can measure the energy of an alpha particle
Measuring the energy of an alpha particle
as well as the position and momentum, I cannot find papers that explore the motion of an alpha particle about its own axis.
Two ways that I thought of to investigate this might be:
the billiard ball analogy - if an alph... |
What is it that make some material look black? What I mean is, why do some atoms absorb photons while others transmit them? (Correct me if I'm wrong but I think all photons are absorbed by an electron, exiting it, and shorty after the electron releases a new photon?)
But what I'm wondering, just to clarify my question,... |
What is a local Lorentz reference frame? How exactly does it differ from an inertial reference frame or a locally inertial reference frame? Are there synonyms of this expression?
|
Hi I was trying to understand the hubble tension. I know that the value infered for $H_{0}$ with supernovae is $H_{0}=74.03\pm 1.5 Km s^{-1} Mpc^{-1}$ and the value infered with the CMB using the standar model of cosmology is $H_{0}=67.39\pm 0.54 Km s^{-1} Mpc^{-1}$ and this values are in a $4.2\sigma$ tensión.
Stati... |
I read the Wiki page
https://en.wikipedia.org/wiki/Electron_cyclotron_resonance
as well as this answer here
How does a cyclotron work?
and it describes a setup where one has a cyclotron which has a static magnetic field pointing up through the dees and there is an alternating high voltage across the dees. An alpha part... |
I read the wiki:
https://en.wikipedia.org/wiki/Hamiltonian_mechanics
It says,
The $q_i$ are called generalized coordinates, and are chosen so as to eliminate the constraints or to take advantage of the symmetries of the problem, and $p_1$ are their conjugate momenta.
Can anyone please point out what does it mean
to ... |
Let a eigenstate of a hamiltonian depend on a parameter $\lambda$, such that
$$\hat{H}_{(\lambda )}\left| n_{(\lambda )} \right> = E_{n \,(\lambda )} \left| n_{(\lambda )} \right> $$
Is it possible to write
$$\left< x \right| \frac{\partial}{\partial\lambda} \left. n_{(\lambda )} \right> = \frac{\partial}{\partial\lamb... |
In reading various sources about universal inflation, it got me wondering if said inflation, creates paradoxes.
Let's say I have a galaxy moving away from me at the speed of light. I lay an imaginary string that is 1/2 a light year across so it is equal distances away from the Milky Way and the other galaxy I want to ... |
It is known that in a single particle quantum mechanics problem with the Hamiltonian, $H = \frac{(\vec p-q\vec A)^2}{2m} + V(\vec r)$, one can perform the following gauge transformation:
$$\vec A \rightarrow \vec A' = \vec A + \vec \nabla \lambda(\vec r),$$
provided we also transform the wave-function, $\Psi(\vec r) \r... |
During the Doppler-free Rb saturation spectroscopy experiment we have the spectrum shift to the left on the frequency axis with increasing current or the temperature. I would appreciate it if anyone can shortly explain why.
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On Griffith's "Introduction to Electrodynamics" page 120 the author states that when proving the First Uniqueness theorem: The solution to Laplace's equation in
some volume V is uniquely determined if V is specified on the
boundary surface S....
We suppose there are two solutions to Laplace equation: $$\nabla^2V_1=0\\\... |
In order to define the usual modes of EM waves in a confined space, TEM, TE and TM, one must have a well defined notion of "transverse" and "longitudinal" in the system. In the case of cylindrical waveguides, there is the axis of translational symmetry and in the case of spherical cavities, there is the radial directio... |
My Background:
In high school, I completed AP Physics C Mechanics and Electricity and Magnetism. In my first year of undergrad, I completed a course on Newtonian Mechanics and a course on Special Relativity and Electromagnetism which both approximately followed the sections on those topics in the Feynman Lectures on Ph... |
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