> No microorganism gets to move for free. Newton’s third law, that every action has an equal and opposite reaction, becomes something of a tautology, for there

> No microorganism gets to move for free. Newton’s third law, that every action has an equal and opposite reaction, becomes something of a tautology, for there are no longer any actions. I acknowledge this post was made by a scientific author catering to the masses who have little experience with physics but this is misleading and wrong. Nothing gets to move for free (according to known laws and our mutual agreement of what it means to have a 'potential' energy) of course including microorganisms. He even contradicts himself by earlier stating that the tiny organisms do move miniscule distances on the order of angstroms, micrometers etc after they stop "swimming" ( applying a force to the water (abiding by newtons third law, and thus, swimming.) They do have both positive and negative accelerations. Taking into account the micro fraction force and size of these tiny "things" compared to larger "things" this conclusion just makes a whole lot of intuitive sense, regardless of ones understanding of Reynolds number Finally, to get a numerical grasp of how the physics is different for small Reynolds number, the average ecoli is 2 micrometers, and an angstrom is 0.0004 micrometers which I admit is interesting, since in one of his exemplary cases, the bacteria only travels 1/5,000 of its average length before stopping, whereas a human may travel maybe 1/2 body length before stopping, swimming at ~0.5 m/s.