I'm learning Griffith quantum mechanics. In quantum mechanics, a particle has variety of accessible energy states. Then is the energy of the particle is conserved always? Energy states is decided randomly, it makes me think energy would not conserved. I got some idea,
1.Average value of energy is...
What I am asking is that $\psi_1 \otimes \psi_2$ and $\psi_2 \otimes \psi_1$ are obviously different states. But I can't find a book that describes or even talk about this? Is it because they don't have experimentally different results?
However, theoretically a measurement can be done that t...
Given $N$ distinguishable quantum particles in the canonical ensemble, we can estimate the probability of finding one of those, labelled by $j$, in a certain position $x\in\mathbb R$ by computing
\begin{equation}
\frac 1{Z_\beta}\mathrm{tr}\{e^{-\beta\hat H} \hat \delta(\hat x_j-x\hat I)\}\equiv ...
I've recently been looking at the quantum mechanical description of a charged particle in an EM field and have come across this classical hamiltonian: $$H = \cfrac{(\mathbf p - q\mathbf A)^2}{2m} + q\phi$$
I can interpret the second term as the electric potential energy of the charged particle in...
I’ve read that the wavelength is invisible for objects at a large scale because it is to small so macroscopic objects can be described with classical physics, and that decoherence causes quantum effects to dissapear on a large scale so classical physics takes over. Which one is it? Or is it both?...
Is it possible that instead of "decay", there actually happens a type of fusion/fission, that yields products of lower or higher rest mass than the reactants ?
I assume this possibility was considered by the pioneers in the field, though I'm not informed of it.
In the former case, a neutron p...
If photon wavefunctions are omnidirectional and don't have a definite size, how comes those from the Sun don't all collapse on Mercury and some do actually reach Earth ?
I understand that wavefunctions describe a cloud of potential parameters, and that an actual particle can materialize at any p...
I'm trying to get the current vector $J^\mu$ of a Klein-Gordon equation:
$\Psi^* \Box \Psi =\Psi^* \partial^{\mu} \partial_\mu \Psi= \partial^{\mu}(\Psi^*\partial_\mu \Psi)-\partial^\mu \Psi^*\partial_\mu \Psi $
$\Psi \Box \Psi^* =\Psi\partial^{\mu} \partial_\mu \Psi^*= \partial^{\mu}(\Psi\...
is it proven by Carbon - dating ?
From Wikipedia -
"While delayed-choice experiments have confirmed the seeming ability of measurements made on photons in the present to alter events occurring in the past, this requires a non-standard view of quantum mechanics"
