Francis Halzen is a leader in the study of neutrinos, ghostly particles from across the universe that hint at exciting new physics

Biological physics is a branch of physics that deals with systems of a biological nature, from the scale of biological molecules to whole organisms and ecosystems. Biological physics typically uses quantitative physical approaches to address biological questions similar to those studied in biochemistry and molecular biology.

This video examines whether modern physics has revived the 19th-century idea of the “aether” — the invisible medium once thought to carry light — and explains how contemporary theories changed our view of space and particles.