When a set of particles is strongly bound to one another, such as in a branched chain polymer, they can form large scale supramolecular structures. Within these structures the individual bonds can vibrate at specific frequencies depending on the bond order, the mass of individual particles, and the energy in the system as a whole.
Resonance structures can be stored as both active energetic passage, where if the energy drops below a threshold the pattern ceases to be self-reinforcing to the point that the inherent structure dissipates. Alternatively they can be a function of the connectivity of the network itself, where injection of energy into the system reinstates those patterns freely. In the language of the Soul the outcomes represent those daily grooves pushed into internal fabric versus those that are folded and scratched fully.
The character of these vibrational couplings allow for the discussion on reinforcing and negating structures. If a structure has a resonance pattern that has a large wavelength, then smaller wavelengths can piggyback on that pattern. However, if the pattern is exceptionally complex or matching amplitudes occur the ability to separate out the source of these resonance patterns grows more difficult. There is significant work in signal processing on this behaviour as well as information theory on the limits of information transfer capacity by a channel in these systems. Crucially it means that if one is to find two patterns in perfect opposition within the network and attempt to inject them they lose their ability to modify the internal structure of the network effectively.
In this way one could view the injection of an inverted vibrational structure into a particle system as effecting change insomuch as it allows other patterns to begin dominating particle interactions. If a system of beliefs is fully nullified, it is not necessarily the new pattern driving future behaviour so much as it is the remaining patterns. In some cases this induces mental collapse as the original pattern was devised to support a large mind, while in the case of the nullity the smaller patterns were not set up to support the full structure.
But I digress. In 2D-SFG the goal is to inject a specific frequency of light to excite particles that are resonating at said frequency. Then at times you measure the energy structure of all frequency to see how energy from said frequency relaxes into the rest of the network. The obvious upside of this is that you can begin to determine how frequency-connected structures are causally co-located. So if a 1650 pulse is put into a system and you see resonances at 1622 then you know that your alpha helices are probably touching your beta sheets.
What this also implies is that certain particles may become loci for resonance and energy accrual. The exact mechanics of this rapidly becomes quite complex, as the dominating structure of the medium determines whether the material is bending or stretching dominated. In extreme cases this may cause particles to dissociate from the bulk material.