He had known both of them for many years since they were close friends with his father and had met as part of a regular discussion group, with both brothers Niels and Harald Bohr taking part as soon as they were old enough to contribute.
Siya ay kilala pareho ng mga ito para sa maraming mga taon dahil sila ay malapit na kaibigan sa kanyang ama at may nakikita bilang bahagi ng isang regular na discussion group, na may parehong mga kapatid na lalaki at Harald Niels Bohr dinadala ng bahagi sa oras na sila ay sapat na gulang upang tumulong.