####
It will interest mathematical circles that the mathematical instruments created by the higher
algebra play an essential part in the rational formulation of the new quantum mechanics.
Thus the general proofs of the conservation theorems in Heisenberg's theory carried out by
Born and Jordan are based on the use of the theory of matrices, which go back to Cayley
and were developed by Hermite. It is to be hoped that a new era of mutual stimulation
of mechanics and mathematics has commenced. To the physicist it will seem first deplorable
that in atomic problems we have apparently met with such a limitation of our usual means
of visualisation. This regret will, however, have to give way to thankfulness that mathematics,
in this field too, presents us with the tools to prepare the way for further progress.

---Niels Bohr

```
Atomic theory and mechanics,
```*Nature*,
Vol. 116, 1925, p. 852.

This article arose out of an address that Niels Bohr delivered,
on 30 August 1925, to the sixth Scandinavian Mathematical Congress in Copenhagen.

The quote is used an an epigraph on p. 276 in *Operator Commutation Relations*
by Palle E. T. Jorgensen and Robert T. Moore, D. Reidel, Dordrecht / Boston / Lancaster, 1984.

This quote from Niels Bohr is also reproduced in vol. 3 of
*The Historical Development of Quantum Theory, Vol. 3:
The Formulation of Matrix Mechanics and Its Modifications, 1925-1926*
by Jagdish Mehra and Helmut Rechenberg,
Springer-Verlag, New York, 1982,
the volume about Max Born and his times.
The quote is on the first page of the
Introduction, i.e., page 3 in vol. 3 of the Mehra-Rechenberg work. This even
constitutes the opening sentences of the Introduction, Mehra describing how
Bohr saw the developments from 1925 on as a revival of the long-established
connection between mathematics and physical theory.
The Bohr quote is from a Scandinavian conference, which is
carefully referenced by Mehra and Rechenberg. They also relied on recorded
conversations, and on the Bohr archives.

Some interesting links for Niels Bohr:

Bohr_Niels
[in the
MacTutor History of Mathematics archive
at the University of St Andrews]

Niels Bohr Archive

to
Quotes selected by Palle Jorgensen