Modern Atom Model: Is It Perpetual Motion?

[dom_quixote]

Is the current atomic model a kind of perpetual motion?

 

[Dale]

Is the current atomic model a kind of perpetual motion?

It is not a perpetual motion machine. “Perpetual motion” is not forbidden by the laws of physics, just “perpetual motion machines”.

 

[PeroK]

Is the current atomic model a kind of perpetual motion?

In a QM atom there is no motion at all in the classical sense. The atom is described by a state (aka wave-function) and is governed by conservation laws, but there are no perpetual classical trajectories.

 

[hutchphd]

The answer will depend upon your definition of Perpetual and Motion...

 

[gentzen]

Is the current atomic model a kind of perpetual motion?

No. It only feels like that, because theoretical quantum mechanics is taught before theoretical statistical mechanics. So you first teach it in a way as if temperature would be exactly zero. But at zero temperature, all degrees of freedom are frozen out, hence all dissipative forces seem to be absent.

On the other hand, with respect to crystallization, molecules and chemical reactions, room temperature is often surprisingly close to zero. (But with respect to electrical and heat conduction, it is not close to zero.) There are some interesting considerations elaborating this near the end of E. Schrödinger's What is life?

NERNST'S THEOREM
When does a physical system - any kind of association of atoms - display 'dynamical law' (in Planck's meaning) or 'clock-work features'? Quantum theory has a very short answer to this question, viz. at the absolute zero of temperature. As zero temperature is approached the molecular disorder ceases to have any bearing on physical events. This fact was, by the way, not discovered by theory, but by carefully investigating chemical reactions over a wide range of temperatures and extrapolating the results to zero temperature - which cannot actually be reached. This is Walther Nernst's famous 'Heat Theorem', which is sometimes, and not unduly, given the proud name of the 'Third Law of Thermodynamics' (the first being the energy principle, the second the entropy principle).
Quantum theory provides the rational foundation of Nernst's empirical law, and also enables us to estimate how closely a system must approach to the absolute zero in order to display an approximately 'dynamical' behaviour. What temperature is in any particular case already practically equivalent to zero?
Now you must not believe that this always has to be a very low temperature. Indeed, Nernst's discovery was induced by the fact that even at room temperature entropy plays an astonishingly insignificant role in many chemical reactions. (Let me recall that entropy is a direct measure of molecular disorder, viz. its logarithm.)

THE PENDULUM CLOCK IS VIRTUALLY AT ZERO TEMPERATURE
What about a pendulum clock? For a pendulum clock room temperature is practically equivalent to zero. That is the reason why it works 'dynamically'. It will continue to work as it does if you cool it (provided that you have removed all traces of oil!). But it does not continue to work if you heat it above room temperature, for it will eventually melt.

THE RELATION BETWEEN CLOCKWORK AND ORGANISM
That seems very trivial but it does, I think, hit the cardinal point. Clockworks are capable of functioning 'dynamically', because they are built of solids, which are kept in shape by London-Heitler forces, strong enough to elude the disorderly tendency of heat motion at ordinary temperature.

 

[CoolMint]

Is the current atomic model a kind of perpetual motion?

It would have been, if it were a model of classical particles in motion.