Thermal Energy; it’s hard to get rid of it – I wondered if there was a particle model of thermal energy and indeed their is; is it a universe superimposed upon our regular way of thinking about things? Maybe. Gonna look now.
https://phys.libretexts.org/Courses/University_of_California_Davis/UCD%3A_Physics_7A_-_General_Physics/03%3A_Applying_Particle_Models_to_Matter/3.04%3A_Particle_Model_of_Thermal_Energy