  What constitutes a scientific discovery? What role do discoveries play in
science, its dynamics and social practices? Must every discovery be attributed
to an individual discoverer (or a small number of discoverers)? The paper
explores these questions by first critically examining extant philosophical
explications of scientific discovery $\unicode{x2013}$ the models of scientific
discovery, propounded by Kuhn, McArthur, Hudson, and Schindler. As a simple,
natural and powerful alternative, we proffer the $\unicode{x201c}$change
$\unicode{x2013}$driver model$\unicode{x201d}$: in a nutshell, it takes
discoveries to be cognitive scientific results that have epistemically advanced
science. The model overcomes the shortcomings of its precursors, whilst
preserving their insights. We demonstrate its intensional and extensional
superiority, especially with respect to the link between scientific discoveries
and the dynamics of science, as well as the award system of science. As an
illustration, we apply the considered models of discovery to one of the most
momentous discoveries of science: the expansion of the universe. We oppose the
2018 proposal of the International Astronomers$\unicode{x2019}$ Union as too
simplistic given the historical complexity of the episode. The
change$\unicode{x2013}$ driver model yields a more nuanced and circumspect
verdict: (i) The redshift-distance relation should not be named the
$\unicode{x201c}$Hubble$\unicode{x2013}$Lema$\unicode{x00EE}$tre
Law$\unicode{x201d}$, but $\unicode{x201c}$Slipher-Lundmark-Hubble-Humason
Law$\unicode{x201d}$; (ii) Its interpretation in terms of an expanding
universe, however, Lema$\unicode{x00EE}$tre ought to be given credit for; but
(iii) The establishment of the expansion of the universe, as an evidentially
sufficiently warranted result, is a communal achievement, emerging in the 1950s
or 1960s.
