I disagree just with the time-dependent description, including "fluctuation", "short-lived" and so on. The interaction is static.
It's something a bit abstract in quantum mechanics. The proper description of two particles is a single wavefunction ψ(ra
, t) where ψ is a complex scalar function as usual but it depends on both particles, here on their positions ra
, t) can't be written as ψa
, t). As the particles rearrange, for instance electrons in molecules, they find combinations of positions that are more favourable than if each particle had a distribution independent of the other ψa
, t). As two electrons repel an other, they are more likely far from an other than very near.
But QM does not need a change over time for that. If you consider a helium atom as a simpler example, its two electrons on 1s have a distribution perfectly independent of time. QM calls it a "stationary" solution, which means "immobile" more or less.
Then the wavefunction is written as a ψ(ra
where |ψ| is independent of time and |ei...
| too, that is, the probability density is perfectly static. Nevertheless, ψ(ra
) can't be written as some ψa
). The probability density of finding both electrons very close to an other is weak because they repel an other. But the probability density of any electron has spherical symmetry nevertheless.
In other words, It's not a matter of "when
" an electron is around that position, then the other has a consequent distribution of probability density. It's "if
". This has no equivalent in the macroscopic world hence is abstract to me.
By the way, this is quantum entanglement. It is extremely common.
The interaction of two molecules does things similar to the helium atom, just more complicated because there are more electrons.
Polar molecules do present the interactions of non-polar molecules too. But dipole interactions tend to be stronger, and then the others maybe neglected.