Die Vereinigung der Schwerkraft und der Quantentheorie erfordert ein besseres Verständnis der Zeit

There is a small, and basically unimportant, error early in the article above When Heisenberg was a visitor in 1925 the islands were part of *Germany* not *Denmark*. This had been the case since 1890 when Germany ceded control of Zanzibar in trade for Heligoland. Prior to this they had been under British control from 1807. See the [Wikipedia article on Heligoland](https://en.wikipedia.org/wiki/Heligoland).