- BOHR
- Physics Nobelist Niels
- Physicist Niels of atomic theory
- Nobel-winning physicist from Copenhagen
- 1922 Physics Nobelist Niels
- Physicist who predicted the existence of the element hafnium
- Quantum physics pioneer Niels
- Physicist Niels
- Quantum theory scientist Niels
- 1922 physics Nobelist
- Planck contemporary
- Niels of physics fame
- Nobel scientist Niels
- Physicist Niels ___
- Danish nuclear physicist
- Quantum-theory pioneer
- Niels or Aage of physics
- Danish physics Nobelist
- He said, "We must be clear that when it comes to atoms, language can be used only as in poetry"
- Co-developer of quantum mechanics' "Copenhagen interpretation"
- Nobel physicist Niels
- Nobel-winning physicist Niels or Aage
- Nuclear physicist Niels ___
- Danish physicist Niels
- Nobelist Niels ___
- He made a model of the 55-Down
- Einstein contemporary
- 1922 Nobelist Niels
- Nobelist Niels
- Niels famous for studying the atom
- Nobelist Niels from Copenhagen
- Physics Nobelist Nils
- Danish nobelist in physics
- 1922 Danish Nobelist
- Los Alamos scientist
- Quantum physics pioneer
- Quantum physicist Niels
- Physicist represented in the play "Copenhagen"
- Nuclear Nobelist Niels
- Father or son physics Nobelist
- Atomic theory pioneer
- Nobelist who developed a model for 63-Down
- Physics Nobelist the year after Einstein
- Physicist played by Branagh in "Oppenheimer"
- Famous physicist Niels
- Danish physicist
- Whom element #107 was named for
- Danish colleague of Einstein
- Nobelist at Los Alamos
- Physics Nobelist the year after Einstein won
- Nuclear physicist.
- Physicist, winner of first Atoms for Peace Award.
- Danish physicist, Nobel Prize winner, 1922.
- Famous Danish physicist.
- Great name in physics.
- Nobelist in physics, 1922.
- Danish Nobelist
- Danish Nobelist, 1922
- Nobel physicist
- Eminent Danish physicist
- Physics Nobelist: 1922
- Nobel Prize physicist: 1922
- Nobel physicist: 1922
- Atomic physicist Niels ___
- Danish atomic physicist
- ___ theory, in physics
- Physics Nobelist who developed an early model of the atom
- Nuclear theorist Niels
- 1922 Nobelist in physics
- Pioneer in quantum theory
- Noted Los Alamos scientist
- Physicist with an element named after him
- Atom modeler
- Nobelist name of 1922 and 1975
- 1920s-'30s debate opponent of Einstein
- Physicist who said "Anyone who is not shocked by quantum theory has not understood it"
- See 25-Down
- Pioneer in atomic theory
- Atom studier Niels
- 1922 Physics Nobelist ... or his son, 1975 Physics Nobelist
- Physicist depicted in Michael Frayn's "Copenhagen"
- Atomic theorist Niels
- Nobel physicist in 1922 or 1975
- Nobel-winning physicist Niels
- Danish physics Nobelist Niels
- Nuclear Niels
- Atomic physicist Niels
- Either of two Nobel-winning physicists
- Nuclear physicist Niels
- Physics Nobel Prize winner
- Niels who modeled the atom
- Danish Nobel Prize winner
- Danish physicist of note
- Atomic physicist
- See 10 Across
- Manhattan Project scientist
- To whom Einstein wrote, "Not often in life has a human being caused me such joy by his mere presence as you did"
- Namesake of a physics institute at the University of Copenhagen
- Surname of father-son physics Nobelists
- Nobelist from Copenhagen
- Niels who won the Nobel Prize for his model of the atom
