Krefsin and Tabergugov as pictured in Gunbuster Science Lessons.

Powder (仮想粒子 lit."Virtual Particle", or "Potential Particle") is a particle mentioned in the Diebuster episode of Gunbuster Science Lessons which revolutionized our understanding of thermodynamics and led to the discovery of Topless. Because the episode has not been translated into English, the specifics of this are currently unknown.

Powder was discovered by a pair of scientists, Dmitry Krefsin (ドミトリー・クレフシン) and Kazbek Tabergugov (カズベク・タベルギゴフ) who are named the "next big scientists" in the field of thermodynamics after Boltzmann and Landauer, similarly to how Tannhauser is referred to as a "modern physicist" in the original Gunbuster Science Lessons: "The ancient physics of Newton, the classical physics of Einstein, the modern physics of Tannhauser".