The most generally accessible argument that molecular machines are feasible is to observe that biological molecular machines exist.
Enzymes can copy DNA with remarkable fidelity.
In 1992, K. Eric Drexler published Nanosystems , which directly addressed the feasibility of molecular machines. He concluded that molecular machines were indeed feasible within the framework of generally understood and accepted physical law. This approximation is discussed in every introductory text on molecular mechanics, for it forms the basis of the field and the foundation for much of modern computational chemistry. A brief and somewhat simplified summary follows. Atoms are made of nuclei and electrons.