"To understand the physics" means acquiring knowledge and comprehension about how the physical world functions, including the laws, principles, and workings of nature. Full definition
Unfortunately, we don't understand the physics of how they work very well at all. (public.nrao.edu)
P.S. — This article is not meant to encourage drag racing but just to make our readers understand the physics behind the pedal and gear knob. (motorbeam.com)
Recent progress in understanding the physics of quantum information has led to novel methods to simulate quantum physics, both on existing classical computers and on future quantum computers. (sciencedaily.com)