From September 1924 until May 1925 he worked, with the support of a Rockefeller grant, with Niels Bohr at the University of Copenhagen, returning for the summer of 1925 to Göttingen. Heisenberg invented matrix mechanics, the first version of quantum mechanics, in 1925.
Mula Setyembre 1924 hanggang Mayo 1925 ay nagtrabaho siya, kasama ang suporta ng isang Rockefeller bigyan, sa Niels Bohr sa University of Copenhagen, bumabalik para sa tag-init ng 1925 sa Gottingen. Heisenberg imbento matris mechanics, ang unang bersyon ng quantum mechanics, sa 1925.