Despite some early indications, largely ignored, resonances in the scattering of electrons by atoms and molecules were unknown until the work of George Schulz in the early 1960’s.
Observing resonances in cross‐section‐versus‐energy curves has long been a way of life for nuclear and particle physicists, for whom this is often the only way to detect short‐lived quantum states. Atomic physicists, on the other hand, have traditionally used other means for observing internal energy states of atoms and molecules. But sixteen years ago a resonance in the cross section for electrons scattering off helium changed the tradition, and by now there is a long catalog of observed resonances in atoms and molecules and an accompanying body of theoretical work that seeks to account for the newly discovered states and explain their behavior.
With strong magnetic fields and intense lasers or pulsed electric currents, physicists can reconstruct the conditions inside astrophysical objects and create nuclear-fusion reactors.
A crude device for quantification shows how diverse aspects of distantly related organisms reflect the interplay of the same underlying physical factors.