  Proteins have been empirically linked to memory. If memory relates to protein
structure, then each conformation would_functionally_ code only one bit, making
it difficult to explain large memories. Nor is there a simple way to relate
memory to protein dynamics on current molecular dynamics (MD), which is
memoryless. Here we point out that MD may be modified to involve memory ab
initio without any new hypothesis: simply replace the electrostatic (Coulomb)
force by the electrodynamic force--which is more accurate. We now need to solve
functional differential equations (FDEs), instead of the ordinary differential
equations (ODEs) currently solved in MD. Unlike ODEs, retarded FDEs are
history-dependent: so memory is already present even at the level of
interacting sites within molecules. The resulting increase in computational
complexity is within the reach of current computers. While Amdahl's law does
pose a challenge to parallelised time-stepping with this model, the
compute-intensive part--the force calculation--may still be carried out in
parallel. Thus, reformulating MD to use FDEs is feasible, and this could help
to understand the possible dynamical basis of memory.
