It must be, if the nebular hypothesis has any truth, older
than our world; and long before this earth ceased to be
molten, life upon its surface must have begun its course.
The fact that it is scarcely one seventh of the volume of
the earth must have accelerated its cooling to the
temperature at which life could begin.
--H. G. Wells, The War of the Worlds, 1898
What makes the tone of the passage formal and scientific?