A tiny, levitated glass sphere behaves like the hottest engine ever made
Summary: At an effective temperature of 13 million kelvins, the jiggling glass sphere could help scientists understand physics at the microscale.
What is a levitated glass sphere?
Scientists trap a micron‑sized glass bead in a vacuum using a combination of magnetic and optical forces. The sphere is suspended in mid‑air, isolated from any external surface, and can be heated to extreme temperatures by laser illumination without direct contact.
How does it reach such temperatures?
By directing a finely tuned laser into the bead, the photons are absorbed and converted into kinetic energy of the sphere’s internal atoms. Because the sphere is levitated, heat can only escape via radiation, allowing the internal temperature to climb to over 13 million kelvins—far hotter than the surface of the Sun—while the surrounding environment remains at room temperature.
Implications for microscale physics
At these temperatures, the glass sphere behaves like a miniature “hot engine,” producing a measurable thermal gradient and generating a controlled flow of photons and charged particles. This opens a new window into studying high‑energy density physics, quantum thermodynamics, and the behavior of matter under extreme conditions in a clean, tabletop setting.
Future experiments and applications
Researchers plan to couple the levitated sphere to superconducting circuits and optical cavities, aiming to observe quantum effects at unprecedented energy scales. Potential applications range from precision force sensing to testing fundamental theories of gravity and quantum field interactions in a levitated, ultra‑hot environment.