no t e s
t h e s c i e n c e a n d e t h i c s o f m a t t e r i n g
1 Outside of physics circles, one ﬁnds that it is often the case that Heisenberg’s
name is known but not Bohr’s. Niels Bohr (1885–1962), a Danish physicist and
contemporary of Einstein’s, was one of the founders of quantum physics. He
won the Nobel Prize in 1922 for his quantum model of the atom. Bohr played a
primary role in founding the so-called Copenhagen interpretation of quantum
physics. In 1921 he founded the Institute in Copenhagen that bears his name.
Many of the fundamental contributions to the new quantum theory were born at
the institute. Werner Heisenberg (1901–76) won the 1932 Nobel Prize in Physics
for ‘‘the creation of quantum mechanics,’’ work he did at the Niels Bohr In-
2 This is not to suggest that all popular accounts of quantum physics sacriﬁce
rigor to other values and interests, but there is no shortage of such texts that do.
3 This question, from an actual a≈davit by Heisenberg, is also uttered by his
character in the play. W. Heisenberg, a≈davit on the Copenhagen visit, manu-
script and typescript, c. 1948, Heisenberg Archive, Max Planck Institute for
Physics, Munich (cited by David Cassidy in Physics Today, July 2002).
4 This quote from Michael Frayn is from his talk for the Niels Bohr Historical
Archive’s History of Science Seminar, November 19, 1999 (available on the
5 Position and momentum are the quantities that Newton tells us are needed to
predict the entire trajectory of a particle—into the future and the past.
6 Frayn, quoted in Justin Davidson, ‘‘Was Something Rotten in Denmark?’’ review
of Copenhagen, Newsday, April 7, 2000, 16.
7 Jungk admits to having been taken in by the ‘‘impressive personalities’’ in-
volved: ‘‘That I have contributed to the spreading of the myth of passive re-
sistance by the most important German physicists is due above all to my esteem
for those impressive personalities which I since realized to be out of place’’
(quoted in ‘‘David Cassidy letter on Heisenberg,’’ published in F.A.S. Public
Interest Report, Journal of the Federation of American Scientists 47, no. 6 [November–
8 The documents have been published on the Niels Bohr Archive website. There
are some twelve extant drafts of Bohr’s letter, written between 1957 and his
death in 1962. This is typical of how Bohr wrote and approached physics prob-
lems as well. He would go over and over the same ground looking at things
from di√erent angles. The drafts are di√erent attempts to get at the heart of
what he wanted to say. They don’t contradict one another; they o√er comple-
mentary approaches to the truth. According to Leon Rosenfeld, a coworker, he
and Bohr worked on one paper for over ten years and had over one hundred
drafts of it.
9 James Glanz, ‘‘Frayn Takes Stock of Bohr Revelations,’’ New York Times, February