The quantum mechanical concept of resonance was introduced by Heisenberg in 1926:
...in a discussion of the quantum states of the helium atom. He compared the structure of the helium atom with the classical system of resonating coupled harmonic oscillators. Linus Pauling used this analogy to introduce his resonance theory in 1928. In the classical system, the coupling produces two modes, one of which is lower in frequency than either of the uncoupled vibrations; quantum-mechanically, this lower frequency is interpreted as a lower energy. link
Such resonance is really an energy exchange mechanism via coupling. Pauling showed that whenever there is resonance between two or more parts, the whole is stabilized. Such resonance differs from mere conjugation: conjugation is just a yoking together--there is no implicit notion of resonance. Resonance requires certain other features--foremost a recognizable likeness (symmetry) and ideally a ring structure (which brings up obvious symbolism).
The notion of resonance extends beyond quantum mechanics and chemistry into mechanics and social interactions. link. It also holds for pair-bonding interactions of other sorts. Communicative resonance spans a greater range of communicative space. The same idea may stimulate two or more people at two different locations. Excitation at one level excites another at a different level. The message resonates right between them-as if through thin air. But there is no real sense of the message being above or below the two: what counts in the quantum mechanical version is the energy overlap and symmetry.
The notion of resonance extends beyond quantum mechanics and chemistry into mechanics and social interactions. link. It also holds for pair-bonding interactions of other sorts. Communicative resonance spans a greater range of communicative space. The same idea may stimulate two or more people at two different locations. Excitation at one level excites another at a different level. The message resonates right between them-as if through thin air. But there is no real sense of the message being above or below the two: what counts in the quantum mechanical version is the energy overlap and symmetry.
Resonance in a compound doesn't necessarily lower the potential energy of the individual atoms does it?
ReplyDeleteIn Pauling's valence bond theory, yes delocalization lowers the ground state energy of the two or more atoms which are already joined. It's a given that the energies of the individual atoms is lowered by joining, otherwise they wouldn't bond.
ReplyDeleteMolecular orbital theory already includes the concept of delocalized electrons and therefore has no need of the concept of resonance.
Sheesh, I smell another blog post.
Still enjoying your book and worrying about all that gold.
@LL A conceptual problem I have with molecular orbital theory is imagining a pair of electrons delocalized over an entire very large molecule, say like graphite.
ReplyDeleteVB theory teaches more of a localized between atoms picture.
Dr. Heisenberg's theory has been extrapolated recently by quantum physicists to suggest that at times electrons actually 'wink out' and then 'wink back' into existence - calling for the possibility that they are also shared interdimensionally. While it sounds like weird science, almost all quantum physics defies logic from a strictly lay perspective of space-time.
ReplyDeleteI think you just lost me there LL. I was aware that electrons could tunnel through potential barriers but winking in and winking out is beyond my ken.
ReplyDeleteCan you link to a deeper discussion?