Figure 2.

Even in the simplest encounter models that represent objects (cells, particles, compounds) as identical spheres (a), the encounter rates strongly depend on encounter mechanisms, cell phenotypes and environmental conditions (b). The confluence of encounter rates at micrometre scale (shaded area, note the constant blue curve), analogous to the confluence of energy scales at which molecular machines operate [28], illustrates the challenge of analysing microbial interactions and could contribute to microbial diversity.