He is an expert in classical mechanics.

He is writing a thesis on celestial mechanics.

He is an expert in analytical mechanics and deeply understands its theory.

Statistical mechanics is a branch of physics that provides a theoretical framework for understanding macroscopic phenomena from a microscopic perspective.

Quantum mechanics is a branch of physics that studies the behavior of microscopic particles.

He is an expert in electrodynamics.

Chromodynamics is a part of particle physics that describes strong interactions.

He contracted brucellosis after returning from a trip abroad.

The use of thermonuclear weapons could potentially cause a major disaster for all of humanity.

Zika fever is an infectious disease transmitted by mosquitoes.