by Mizu Ota and Su­san S. Golden — Though we live on the same planet, the world of bac­te­ria is far re­moved from our own, largely be­cause of the sheer dif­fer­ence in size. Life on the mi­crom­e­ter scale is gov­erned by rules that do not con­strain us, and vice versa: aquatic en­vi­ron­ments are dom­i­nated by vis­cous forces, and ex­ter­nal stim­uli such as chem­i­cal gra­di­ents oc­cur on a scale too large to sense over the length of a sin­gle bac­te­r­ial cell...