Gentzen, thanks for investigating. :-) My copy of that arxiv paper is dated February 15, 2024. So I probably became aware of it also through Peter Woit's blog. But bhobba has been referring to it frequently.
A while ago @bhobba pointed to an interesting paper by T Padmanabhan: "Obtaining the Non-relativistic Quantum Mechanics from Quantum Field Theory: Issues, Folklores and Facts" (https://arxiv.org/abs/1712.06605).
I think the first alternative is better, but it depends on how you define ΔE and Δt. For ## \Delta t ## it is customary to use the lifetime of the decaying particle, and for ## \Delta E ## the full-width-half-maximum (FWHM) of the line in the energy spectrum. The line shape is typically fitted...
A vector ## \ket{\Psi} ## in Hilbert space, multiplied by any complex number(*), represents exactly the same state. That's why it is possible to call ## e^{iEt} \ket{\Psi} ## "stationary" even though the phase factor may vary rapidly. Then all expectation values are time-independent. But this...
Wavefunctions are usually written down in a coordinate system where the z-axis is singled out, i.e. the azimuthal quantum number ## m ## refers to the component of angular momentum in the z-direction. For p-orbitals having ## l=1 ## we have one wavefunction (## m=0 ##) proportional to ##\cos...
There is a difference between the Maxwell-Boltzmann distribution (applying to particles with mass) and the more general Boltzmann factor ## e^{-E/kT} ##. The mean energy of a single mode of the radiation field with frequency ## \nu ## can be written as a series of Boltzmann factors: $$
{ h\nu...
What is considered real is important (physics is about the real world around us!), but it is subject to change. Every physicist considers the electric field real, but it once was a completely abstract concept describing stress in a hypothetical material medium (the ether). Everybody seems to...
I don't think this is a meaningful distinction. Of course we are talking about physical reality -- unless you give up on the idea that physics is concerned with the real world around us. As science evolves, what is considered real can change (caloric, ether, "lines of force", phlogiston, ...)...
Photons are surely part of QED, and we have become so accustomed to the term that most physicsts consider them real (apart from those who consider them "mathematical artifacts" of perturbation theory).
I agree with you. Except that the language is deceptive. We are talking of creation and...
Also experiments require interpretation. Whenever we discuss experiments we rely on some theoretical (or proto-theoretical) framework. If yours is different, it doesn't mean that somebody else's must be non-scientific.
It's curious that so many people believe that. Shouldn't we aim for a...
Locality, causality, and determinism are firmly rooted in the classical (macroscopic) world picture. There is no reason to believe that these concepts must necessarily carry over to quantum theory. I quite like Maudlin's discussion of non-locality, but I strongly disagree with his take on...
I don't think Q-day is imminent. (Certainly not on a timescale of a decade!) All that talk of qubits notwithstanding, quantum computers are analog, not digital devices (https://arxiv.org/abs/2312.17570).
Theoreticians can conceive of perfect ## \pi/2 ##-pulses turning ## \ket 0 ## into ## \ket...