Temperature dependence of the fluorescence quantum yield and decay time of several rare-earth chelates have been studied in an attempt to understand the quenching mechanisms in these compounds. It is observed that the quenching in either the ligand or the ion is reduced by lowering the amplitude of molecular vibrations. This indicates that a major part of the fluorescence quenching in rare-earth chelates occurs due to coupling of the electronic states to the environment through molecular vibrations. The results of the present measurement also indicate that the shielded 4f orbitals of the rare-earth atoms become more impervious to quenching when they are incorporated into a chelate. Importance of these results in connection with liquid laser research is discussed.

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Einstein is considered by many as the father of quantum physics in some sense. Yet there is an unshakable view that he was wrong on quantum physics. Although it may be a subject of considerable debate, the core of his allegedly wrong demurral was the insistence on finding an objective reality underlying the manifestly bizarre behavior of quantum objects. The uncanny wave-particle duality of a quantum particle is a prime example. In view of the latest developments, particularly in quantum field theory, Einstein's objections are substantially corroborated. Careful investigation suggests that a travelling quantum particle is a holistic wave packet consisting of an assemblage of irregular disturbances in quantum fields. It acts as a particle because only the totality of all the disturbances in the wave packet yields the energy momentum with the mass of a particle, along with its other conserved quantities such as charge and spin. Thus the wave function representing a particle is not just a fictitious mathematical construct but embodies a reality of nature as asserted by Einstein.

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