What did Marie Curie show about the internal dynamics of molecules? I thought that she was doing radioactivity? I think that what he means that whatever vibrat

What did Marie Curie show about the internal dynamics of molecules? I thought that she was doing radioactivity? I think that what he means that whatever vibrational or rotational internal states the molecule would have, the molecule is almost always in a superposition of all of its possible states (a "smudge" of all possible vibrations, so to say), and because the states are cyclic/vibrational, there is no time evolution.