  What will happen if two identical microspheres, with fundamental whispering
gallery modes excited in each of them, become optically coupled? Conventional
wisdom based on coupled-mode arguments says that two new modes, bonding and
anti-bonding, with two split frequencies would be formed. In this paper we
demonstrate, using exact multi-sphere Mie theory, that in reality an attempt to
couple two fundamental modes of microspheres would result in a complex
multi-resonance optical response with the field distribution significantly
deviating from predictions of coupled-mode type theories.
