Typhoon wrote:Parodite wrote:Thank you for the links. Maybe there are also some fundamental questions left to be asked about quantization. What exactly happens when an atom jumps from one energy state to another for instance? When I walk from a > b the distance is covered in discrete steps. But jumping from one leg to another does not happen via magic steps emerging from a magical hat; there are transitions between those steps. Maybe ideas exist how this "discrete" jumping in qm occurs mathematically in an otherwise deferentially calculated universe that you know of?
. . .
I think you're trying to relate everyday experience to QM.
The two are fundamentally different.
I expect that to be the case but am not there yet. Right now I'm cutting my way through loads of "not even wrong" nonsense, language abuse and PR of snake oil salesmen who sell QM as one would try to sell a magicians toolbox and manual. "A particle that can be a two places at the same time! A dickhead that goes through two sl*ts at the same time and interferes with itself! Come and see the magic!"
![Cool 8-)](./images/smilies/icon_cool.gif)
(I understand.. they need funding too and want to raise public interest in their work)
Probably I end up in the
agnostic church of Feynman... where simply no ontological claim is made about things unknown, unobserved/measured. But as a physicist there was no doubt in his mind: QM is very weird. Don't even try to make sense of it. But I defy my own expectations here and assume he was mad and surrendered to this God called Unknoweability. It is a religious kinda reflex when the going gets tough.
![Uber Geek :ugeek:](./images/smilies/icon_e_ugeek.gif)
(perhaps even a Jewish thing)
A lot of clever people have spent a lot of time trying to come up with a supposedly more fundamental "gears, levers, and wheels" underlying mechanism for QM. Zero successful results to-date.
I know. But it isn't clear to me so can't subscribe to that.
Mechanics is supposed to be about gears, levers. and wheels. QM is also and still full of them. The particle-like behavior as observed in qm experiments for instance. Even the double-slit experiment is a purely mechanical event with causes and effects. They may not be totally understood but that doesn't make things necessarily weird or different from the usual gears, levels and wheels models that rule most of physics even today.
All evidence to-date is that QM is the fundamental description of nature.
But there is no gravity and general relativity in QM as of yet.
Note that QM describes how, energy eigenstates in your example above, not why. This is physics in general.
Progress starts with a why-question and then through observation, theory and experiment a how-answer emerges when results can be reproduced under controlled conditions. Then how-answers usually give rise to new why-questions and so science rolls forward. Why is the buck stopping at the eigenstates and no further
why allowed or possible?
This is one of the things that intrigues me and for which there may be an answer: is there a "look no further beyond QM" because 1) in QM we have reached a
practical limit to investigate these matters any further, 2) from QM theory and all experiment it follows naturally there simply isn't anything above or beyond the QM model possible; no hidden variables (local nor non-local), or other known and unknown unknowns are feasible. Usually one encounters the latter claim: but I haven't found the rationale or proof for that.
A physicist once explained it like this, as I remember it: In theory it is always possible that there is more physics involved in QM that we are not aware of but nothing to date points to what that could or should be. QM works and predicts fine without the need to add or remove anything.
I would think that in any case there is a practical limit to investigate the nature of very small systems and to how bigger systems behave as multi-particle quantum systems. But if an ontological statement can be made that the qm description is fundamental and complete... that is a bridge too far. Also given the problems of QM with gravity and general relativity.
It seems safer to assume that all theory and practice, also QM, are approximations within a limited domain of validity. I'm skeptical a theory of everything will ever be "complete" enough to satisfy everybody. The eternal "why" will always peep through the cracks.
In QM, one sets up and solves the time-independent
Hamiltonian* to get the energy eigenstates of the system, for example, the hydrogen atom.
That's it.
Transition between energy states is by the absorption or emission of a quantum of energy - a photon of light:
[The first three spectra are the emission spectra of excited gases of hydrogen (H), mercury (Hg), and neon (Ne), respectively.
The bottom spectrum is the absorption spectrum of hydrogen.]
*
Hamiltonian mechanics
Yes, this is also explained in the two videos I posted on QM made easy.