概要：We introduce a new active nematics system made of swarming filamentous bacteria. We show that the complex spatiotemporal dynamics of our system can be quantitatively reproduced by a new type of microscopic model for active suspensions whose parameters are all estimated from comprehensive experimental data. This provides unprecedented access to key effective parameters and mechanisms governing our system. Our approach is applicable to different types of suspensions and shows a path towards more quantitative active matter research.