On the occasion of your 60th birthday, when you can look back on a life’s work which has in such rich measure contributed to the development of the physical sciences in our time, all of us here in Copenhagen send you our most heartfelt congratulations. In particular, I think of everything you achieved during the years when it was our great pleasure to have you as a colleague at the Institute, and in the Festschrift that you will receive on your birthday, I have tried to evoke some of the memories from that time, but that does not mean that I have forgotten everything that has happened since and in which you have played such a leading role. We have all followed your bold thoughts in recent years with excitement and look forward to hearing more about them when, as you told me in Brussels, you come to Copenhagen for a visit in the spring.
In recent years I have become increasingly engaged with historical questions, and as I think I told you, as a first effort I have just completed an account of my recollections of Rutherford and of the developments which his discovery of the atomic nucleus led to and which I look forward to being able to send to you soon.
I hope that, when we meet again, we shall also find the opportunity to talk a little about our experiences throughout the many years, not least during the war, when the long separation between the countries gave rise to different views of events and endeavours.
Margrethe and I send Elisabeth and you and your children our fondest greetings and warmest wishes for many happy years.