single mass? Were the planets struck from the sun by
the chance impact of comets, as Buffon has suggested?
or thrown out by explosive volcanic action, in accordance
with the theory of Dr. Darwin? or do they owe
their origin to some unknown law? In any event, how
chanced it that all were projected in nearly the same
plane as we now find them?


LAPLACE AND THE NEBULAR HYPOTHESIS

It remained for a mathematical astronomer to solve
these puzzles. The man of all others competent to
take the subject in hand was the French astronomer
Laplace. For a quarter of a century he had devoted
his transcendent mathematical abilities to the solution
of problems of motion of the heavenly bodies.
Working in friendly rivalry with his countryman Lagrange,
his only peer among the mathematicians of the
age, he had taken up and solved one by one the problems
that Newton left obscure. Largely through the
efforts of these two men the last lingering doubts as to
the solidarity of the Newtonian hypothesis of universal
gravitation had been removed. The share of Lagrange
was hardly less than that of his co-worker; but Laplace
will longer be remembered, because he ultimately
brought his completed labors into a system, and,
incorporating with them the labors of his contemporaries,
produced in the Mecanique Celeste the undisputed
mathematical monument of the century, a fitting complement