Lockyer's Meteoric Hypothesis
Following up the surprising clews thus suggested,
Sir Norman Lockyer, of London, has in recent years
elaborated what is perhaps the most comprehensive
cosmogonic guess that has ever been attempted. His
theory, known as the “meteoric hypothesis,” probably
bears the same relation to the speculative thought of
our time that the nebular hypothesis of Laplace bore
to that of the eighteenth century. Outlined in a few
words, it is an attempt to explain all the major phenomena
of the universe as due, directly or indirectly, to
the gravitational impact of such meteoric particles, or
specks of cosmic dust, as comets are composed of. Nebulæ
are vast cometary clouds, with particles more or
less widely separated, giving off gases through meteoric
collisions, internal or external, and perhaps glowing also
with electrical or phosphorescent light. Gravity eventually
brings the nebular particles into closer aggregations,
and increased collisions finally vaporize the entire
mass, forming planetary nebulæ and gaseous stars.
Continued condensation may make the stellar mass
hotter and more luminous for a time, but eventually
leads to its liquefaction, and ultimate consolidation—
the aforetime nebulæ becoming in the end a dark or
planetary star.
The exact correlation which Lockyer attempts to
point out between successive stages of meteoric condensation
and the various types of observed stellar bodies
does not meet with unanimous acceptance. Mr.
Ranyard, for example, suggests that the visible nebulæ
may not be nascent stars, but emanations from stars,
and that the true pre-stellar nebulæ are invisible until
condensed to stellar proportions. But such details
aside, the broad general hypothesis that all the bodies
of the universe are, so to speak, of a single species—
that nebulæ (including comets), stars of all types, and
planets, are but varying stages in the life history of a
single race or type of cosmic organisms—is accepted
by the dominant thought of our time as having the
highest warrant of scientific probability.
All this, clearly, is but an amplification of that nebular
hypothesis which, long before the spectroscope gave
us warrant to accurately judge our sidereal neighbors,
had boldly imagined the development of stars out of
nebulæ and of planets out of stars. But Lockyer's
hypothesis does not stop with this. Having traced the
developmental process from the nebular to the dark
star, it sees no cause to abandon this dark star to its
fate by assuming, as the original speculation assumed,
that this is a culminating and final stage of cosmic existence.
For the dark star, though its molecular activities
have come to relative stability and impotence,
still retains the enormous potentialities of molar motion;
and clearly, where motion is, stasis is not. Sooner
or later, in its ceaseless flight through space, the dark
star must collide with some other stellar body, as Dr.
Croll imagines of the dark bodies which his “pre-nebular
theory” postulates. Such collision may be long
delayed; the dark star may be drawn in comet-like circuit
about thousands of other stellar masses, and be
hurtled on thousands of diverse parabolic or elliptical
orbits, before it chances to collide—but that matters
not: “billions are the units in the arithmetic of eternity,”
and sooner or later, we can hardly doubt, a collision
must occur. Then without question the mutual
impact must shatter both colliding bodies into vapor,
or vapor combined with meteoric fragments; in short,
into a veritable nebula, the matrix of future worlds.
Thus the dark star, which is the last term of one series
of cosmic changes, becomes the first term of another
series—at once a post-nebular and a pre-nebular condition;
and the nebular hypothesis, thus amplified,
ceases to be a mere linear scale, and is rounded out to
connote an unending series of cosmic cycles, more
nearly satisfying the imagination.
In this extended view, nebulæ and luminous stars are
but the infantile and adolescent stages of the life history
of the cosmic individual; the dark star, its adult
stage, or time of true virility. Or we may think of the
shrunken dark star as the germ-cell, the pollen-grain, of
the cosmic organism. Reduced in size, as becomes a
germ-cell, to a mere fraction of the nebular body from
which it sprang, it yet retains within its seemingly non-vital body all the potentialities of the original organism,
and requires only to blend with a fellow-cell to
bring a new generation into being. Thus may the
cosmic race, whose aggregate census makes up the
stellar universe, be perpetuated—individual solar systems,
such as ours, being born, and growing old, and
dying to live again in their descendants, while the universe
as a whole maintains its unified integrity throughout
all these internal mutations—passing on, it may be,
by infinitesimal stages, to a culmination hopelessly beyond
human comprehension.
