Margrethe and I send you many heartfelt congratulations on the occasion of your birthday, when you can look back on such a rich life’s work in the service of the physical sciences. In particular, I think of all you achieved in the years when it was our great pleasure to have you as a colleague at the Institute in Copenhagen, and I have written a little about the memories from that time in the Festschrift that you will receive on your birthday. That does not mean that I have forgotten everything that has happened since, in which you have always played such a leading role. We have all followed your work in recent years with excitement and look forward to learning more about it when, as you told me in Brussels, you come to Copenhagen for a visit in the spring. I also hope that we shall then have the opportunity to talk to each other in greater detail about what happened during the war, about which I have been asked by so many interested parties/circles, among which such
great historical interest in precisely those eventful times is now arising.
With the wish for many more productive working years, we send you and Elisabeth and the children the warmest wishes.