Many celestial objects such as stars or planets contain matter that is exposed to high temperatures and pressure—experts call it warm dense matter (WDM). Although this state of matter on earth only occurs in the earth's core, research on WDM is fundamental for various future areas such as clean energy, harder materials or a better understanding of solar systems. In a study recently published in Physical Review Letters, a team led by physicist Dr. Tobias Dornheim of the Center for Advanced Systems Understanding (CASUS) at Helmholtz Center Dresden-Rossendorf (HZDR) and alumnus of Kiel University (CAU), now reveals that warm dense matter behaves significantly differently than assumed, which calls into question its previous description.