How to Stuff 170 Atoms Inside a Single Atom

How to put 170 atoms in an atom

Atoms are mostly empty space—the nucleus is tens of thousands of times smaller than the electron's orbital. By exciting an electron to a far-out orbit, scientists create a 'Rydberg atom' over 1000 times wider than normal. Then, using a Bose-Einstein condensate to cool other atoms to near absolute zero, they can trap them inside that inflated orbital, forming a bizarre 'Rydberg polaron.' In 2018, researchers did this with strontium, and simulations suggest up to 170 atoms could fit inside one atom, offering new insights into quantum mechanics.