11
The Kapteyn Universe
One thing is sure. We have to do something.
We have to do the best we know how at the moment.
If it doesn’t turn out right, we can modify it as we go along.
Franklin Delano Roosevelt (1882–1945).
In science it is better to be wrong than to be vague.
Often we find the right way only after we tried all the wrong ways first.
That is why it is fun to be a scientist.
You don’t need to be afraid of being wrong.
Freeman John Dyson (1923–2020)
11.1 The First World War
The Great War, as the First World War is sometimes called, had in many ways
an important, even decisive effect on Kapteyn, his work and his private life, as I
am sure it must have had on that of almost everyone at the time. He had to give
up his annual visits to Mount Wilson. But that was not such a big problem,
as he had an excellent colleague in Frederick Seares, who very effectively kept
the work with the 60 in. for the Plan of Selected Areas going. Dutch neutrality
made it possible to continue correspondence, albeit with delays. Kapteyn, for
example, maintained a lively correspondence with George Hale on a whole
From Dyson’s Oppenheimer Lecture (2000) [100].
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2021
P. C. van der Kruit, Pioneer of Galactic Astronomy: A Biography of Jacobus C. Kapteyn,
Springer Biographies, https://doi.org/10.1007/978-3-030-55423-1_11
225
The Kapteyn Universe
One thing is sure. We have to do something.
We have to do the best we know how at the moment.
If it doesn’t turn out right, we can modify it as we go along.
Franklin Delano Roosevelt (1882–1945).
In science it is better to be wrong than to be vague.
Often we find the right way only after we tried all the wrong ways first.
That is why it is fun to be a scientist.
You don’t need to be afraid of being wrong.
Freeman John Dyson (1923–2020)
11.1 The First World War
The Great War, as the First World War is sometimes called, had in many ways
an important, even decisive effect on Kapteyn, his work and his private life, as I
am sure it must have had on that of almost everyone at the time. He had to give
up his annual visits to Mount Wilson. But that was not such a big problem,
as he had an excellent colleague in Frederick Seares, who very effectively kept
the work with the 60 in. for the Plan of Selected Areas going. Dutch neutrality
made it possible to continue correspondence, albeit with delays. Kapteyn, for
example, maintained a lively correspondence with George Hale on a whole
From Dyson’s Oppenheimer Lecture (2000) [100].
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2021
P. C. van der Kruit, Pioneer of Galactic Astronomy: A Biography of Jacobus C. Kapteyn,
Springer Biographies, https://doi.org/10.1007/978-3-030-55423-1_11
225