Bohr was well aware of this shortcoming (and others), and had written to his friend Wolfgang Pauli to ask for his help in saving quantum theory (the system now known as "old quantum theory").
Bohr sadar akan kekurangan ini (dan yang lainnya), dan menulis surat kepada temannya Wolfgang Pauli untuk meminta bantuannya menyelamatkan teori kuantum (sistem yang sekarang dikenal sebagai "teori kuantum lama").