FYI to Fran and other Fluctuating Vacuum Vorts:
Fran, I believe this paper is at least in the ball park of one of your pet hypotheses. and having to do with Casimir effect and the exclusion of longer wavelength vacuum fluctuations from small confines. I'm working 70+ hours a week so do not have time to read and comment on it. Controlling the emission of light? Size matters http://phys.org/news/2014-02-emission-size.html "The scientists have obtained a new understanding on how so-called **vacuum fluctuations are inhibited in the photonic crystals**. This study paves ways for applications such as efficient LEDs, lasers, and photovoltaics, and even quantum computers where it is desirable to suppress the fluctuations of the qubits. Their theoretical results are being published in the leading journal Physical Review B that is published by the American Physical Society (APS)." -mark iverson

