His work i believe is great with Biology and Psychiatry etc. since it elucidates how humans are turned into subjects, but how does he reject grand theories derived from Physics which simply describes objective reality as it can be empirically measured and demonstrably shown to exist via experiments ? How do epistemes subjectify physics ? What dominant discourses of power can be hidden in physics ?
If you are talking about fundamental physics, the object of that program is to boil out any cultural, societal, religious or political content from the sought-after description of the universe so that anyone anywhere will obtain the (same) correct answer to any given question they could pose about the universe. In this sense, there is no power discourse content in fundamental physics.
If you are talking about paying for fundamental physics, the tools required to get those answers are extremely expensive, which excludes all but the most wealthy nations (or in some cases individuals) from the practice. Power relations then determine who gets to host the tools and operate them, even in wealthy nations (see for instance the history of the defunct superconducting supercollider in the US).
If you are talking about training people to design, operate, and interpret the results from those tools, then power relations play a key part in the sense that the schools where the relevant subjects are taught are highly specialized and furnish no immediately useful results to help communities. Decisions on who builds the school and who is allowed to attend it are value-laden, subjective, and controlled by power discourse.
If you are talking about which individuals are qualified to participate in this field, an effortless and entirely natural mastery of the most abstract and subtle mathematics known to humanity is a necessary prerequisite, since the truths of the universe are written in the language of mathematics. Because it relies on people with these extraordinary gifts, the practice of fundamental physics has been criticized as elitist, ableist, and fundamentally exclusionary (all of which criticisms I fundamentally reject as nonsensical).