I have read this question:
An isolated atom in a' excited state woul remain there forever.
How soon does an electron emit the absorbed photon back?
These solutions are time independant so an excited hydrogen atom like 2p1 will remain stable forever. But in emission and absorption the system is not time independant because now we have a three component system of an electron, a proton and an electromagnetic wave (or photon if you prefer), and of course the EM wave has to be time dependant because it travels at c. The Schrodinger equation for this system is not the same as the Schrodinger equation for an isolated hydrogen atom, and the solutions are not the hydrogenic orbitals.
However my understanding is that everything in the universe that we know of is trying to reach the lowest possible energy level, that is, for an atom, the ground state. And as far as I understand, even an isolated atom exists in vacuum, that is permeated by the fields, that is for example, the EM field. Now if the EM field permeates all vacuum, then the isolated atom will be able to transfer energy from the electron field (electron/atom system) to the EM field (in the form of a photon emission). After all, the atom is just made up of excitation of fields, like the quark field, the electron field. If it exists, that means it exists inside the fields, that permeate all vacuum.
So how could an isolated atom remain in an excited state forever?
So just to clarify, the atom itself is made up of quarks and electrons, excitation of fields, and so if it exists, then there must be fields present, and these fields should be able to transfer energy to other fields (EM), to emit photons and relax to ground state.
How can an isolated atom remain in an excited state forever?
