  In 1905 the well-known physicist Max Planck was coeditor of the Annalen der
Physik, and he accepted Einstein's paper on light quanta for publication, even
though he disliked the idea of "light quanta". Einstein's relativity paper was
received by the Annalen der Physik at the end of June 1905 and Planck was the
first scientist to notice Einstein's relativity theory and to report favorably
on it. In the 1905 relativity paper Einstein used a seemingly conventional
notion, "light complex", and he did not invoke his novel quanta of light
heuristic with respect to the principle of relativity. He chose the language
"light complex" for which no clear definition could be given. But with
hindsight, in 1905 Einstein made exactly the right choice not to mix concepts
from his quantum paper with those from his relativity paper. He focused on the
solution of his relativity problem, whose far-reaching perspectives Planck
already sensed.
