Recent content by Demystifier

Which, by writing ##q=x##, ##p=y##, becomes the usual quantum mechanical continuity equation. So pre-quantization, at this level, is equivalent to quantization in a doubled number of space dimensions.

Nice question and apparent paradox, let me demystify it. To simplify the math I will work in units ##\hbar=1##, so that position and momentum can be measured in the same units. And to reduce the apparent mystery to something well understood, I will change the notation by writing ##p\equiv y##...

When the intensity of the laser beam is very strong, i.e., when the average number of photons is large, then the laser beam can very well be described as a classical electromagnetic wave. It's only for the low intensity laser beams that its quantum properties become pronounced. But those quantum...

In principle, we could completely ignore statistical mechanics and thermal energy, and explain everything as you would like, in terms of causal directional forces. In fact, that would be more correct to do. But to do that, we would need to keep track of every atom, and for systems with a huge...

The QED Hamiltonian determines the time-dependence of the state ##|\psi(t)\rangle##. But once you know ##|\psi(t)\rangle##, you don't longer need the Hamiltonian to determine the wave function ##\psi({\bf x},t)## from the one-photon state ##|\psi(t)\rangle##.

Yes, but its absolute value squared is not exactly the probability density of photon position.

What was only Imaginary until recently, now is Real. That is, now I=R. Hence, an anagram of PUTIN is TRUNP.

I have never seen that in any book. Unless you mean the drawing of the wave function, it's difficult to draw a complex function, so drawings often present only the real part.

If you can't explain it simply, you don't understand it well enough. - A. Einstein

It's always true, the commutator expresses something which is valid for all states. The true magic of quantum mechanics is not so much in the nontrivial commutators as it is in nontrivial quantum states.

That is certainly wrong. Any detection is associated with decoherence.

The paper is silly, to put it mildly. The crux of their argument is that the set of axioms is arithmetically expressive and therefore Godel's incompleteness theorems apply. That's silly because there is no reason for a computer program running the simulation to be arithmetically expressive. The...