If ‘in your field,’ in which you list ‘science,’ refers to science in general (I consider myself something of a generalist), and to man-made innovations or inventions, as opposed to those achieved by Darwinian evolution, I vote for the invention of language. Language really distinguishes man from beast (be that beast early man). Language makes possible the accumulation of knowledge, including science, and its transmission from generation to generation. Oral language began to make that possible. Written language was an enormous facilitator to the progress of science, and everything else. The computerisation of language will likely result in the next major enhancement of language in leading our march to understanding.
Gilbert V Levin is the founder of Spherix, developer of Naturlose, and life detection experimenter on the Viking mission to Mars which DID find living microorganisms in the soil of Mars