Virginia Trimble
Abstract.
The year 2013 marks the 100th anniversary of the first of two brief papers
by Henry Moseley (1889−1915) in which he provided laboratory evidence that atomic
number (Z, the charge on a nucleus) was more fundamental than atomic weight (the
total number of particles, A, in a nucleus). He had been trained as a physicist; the most
immediate impact was on chemistry (though physics eventually took over much of the
territory); and the sorting out of the two concepts provided the foundation on which
the modern understanding of nucleosynthesis in stars could be built.
This discussion is a very preliminary one, drawing items from a disparate col-
lection of secondary and tertiary sources. Additions, subtractions, and corrections
from readers would be most welcome. The sections that follow provide “snapshots”
of the status of astronomy, chemistry, and physics in 1863, 1913, 1963, and 2013, with
sporadic mentions of one field contributing to another, invading another, or taking over
parts of another. The last section focuses on more of the overlaps. If there is a lesson, it
is that the fraternizers are more likely to be remembered than the isolationists, though
this is at least partly a “history is written by the winners” effect.
Keywords: history and philosophy of astronomy – astrochemistry
Department of Physics and Astronomy, University Of California, Irvine CA 92697-4575, USA