Many space plasmas, like those in Earth’s magnetosphere and the solar wind, are made of particles that rarely collide. In these environments, particles behave differently than in everyday gases. Instead, they form complex structures in their motion and energy. Scientists observe this behavior using computer simulations and spacecraft like NASA’s MMS and Parker Solar Probe. One big puzzle is how energy is exchanged between the random motion of particles and the overall flow of the plasma. Modeling of plasma suggest that certain forces, like those associated with pressure, play a key role in this energy exchange—but the how remains unclear, especially on small scales. In this study, we tackle the problem from a more fundamental perspective, using a simplified model that looks at the behavior of individual particles in detail. This helps us better understand how energy conversion really works in space plasmas that do not behave like ordinary fluids.