How quickly can a bacterium grow?
All living things must obey the laws of physics — including the second law of thermodynamics, which states that the universe’s disorder, or entropy, can only grow. Highly ordered cells and organisms appear to contradict this principle, but they actually do conform because they generate heat that increases the universe’s overall entropy.Still, questions remain: What is the theoretical threshold for how much heat a living cell must generate to fulfill its thermodynamic constraints? And how closely do cells approach that limit?In a recent paper in the Journal of Chemical Physics, MIT physicist Jeremy England mathematically modeled the replication of E. coli bacteria and found that the process is nearly as efficient as possible: E. coli produce at most only about six times more heat than they need to meet the constraints of the second law of thermodynamics. “Given what the bacterium is made of, and given how rapidly it grows,...