2.
Kant's hypothesis, like many syntheses of geniuses,
remained ignored
in his time. But at the beginning of
the nineteenth century, another
hypothesis emerged
which was to enjoy a resounding success through the
associations it awakened in the imagination, namely,
the idea of a
Primordial Nebula.
The idea did not come out of Kant's system, but from
the observations of J.
F. W. Herschel on nebulae. These
remote cosmic clouds exercised a strange
attraction as
soon as they were discovered. Herschel had discerned
in
these accumulated gases that the nebular matter
condensed more or less
around more luminous nuclei;
he had thought he recognized in them embryonic
stars
in various stages of development (Memoir,
1811). Lap-
lace took up the idea, and brought
it closer to home
by applying it to the formation of the solar system
(Système du monde, 1824). For
Laplace, a particularly
objective scientist, astronomy was “the
solution of a
large problem in mechanics.” Concerned solely
with
explaining the direction of planetary motion, he offered
his
account “with all the reservations that should be
induced by
everything which is not a result of observa-
tion and reasoning.” And he said this in a terse and
coldly neutral tone. Now we know that this theory met
with an enormous
success, a success whose causes are
far from being purely intellectual
(even among true
astronomers).
Thanks to Herschel, and then to Laplace, an exalted
idea, taken up again by
many cosmologists (e.g., H.
Faye, and by J. H. Jeans, The
Nebular Hypothesis,
1923), was to fascinate the imagination: the
genesis of
the universe is in continual process under our very eyes.
And philosopher-poets like Lamennais multiplied such
metaphors: for
example, the worlds “appear to us at
first like the small egg in
which the liquid of life
thickens gradually” (Esquisse d'une philosophie, IV
[1846]).
The gropings of scientific explanations take turns in
thwarting or favoring
the nebular reverie. Telescopes
of increasingly greater power reveal in the
nebulae no
longer fragments of primordial chaos waiting to give
birth
to new worlds, but simple masses of stars, a far
less exciting idea.
Herschel was familiar with this dis-
appointment, but the strongest disappointment was
caused by the
giant telescope of Lord Rosse (1845).
The imagination, however, takes
refuge in its origins;
if prime matter no longer exists as the mother
of
worlds, at least it has existed. The joy of seeing creation
in the
process makes room for the nostalgia of the
vanished Mother, and especially of
our
nebula, the
Mother of our solar family (in the poetry of J.
Laforgue).
The resurrection, by means of spectrum
analysis, of the gaseous nebula
(1864) released, for
example, in Flammarion's
Astronomie populaire (1864;
Popular Astronomy, 1879), a delight whose sources
are
suspicious. Henceforth, said the astronomer, we can
see in these
“lights which palpitate on the frontiers
of creation”
the “genesis which shows us the birth of
other
Universes.” It was the same emotion of young
Kant concerning the
fringes of Chaos.
The discovery of spiral nebulae (1845) threw the
dream again on to new
paths. The observer thought
himself the eyewitness of the great tournament
thanks
to which systems have been formed. The arms of the
spiral can
only be imagined as moving, as either curling
up or unrolling. Whether it
is a condensation or dis-
persion, it is
still a matter of genesis. The whirlwind
motion (very different from
circular rotation, eternally
the same) is essentially creative. Dispersion
triumphs
in the hypotheses of S. Arrhenius (Evolution of
Worlds,
1907) and of J. H. Jeans (The Universe
Around Us,
1929) which have so powerfully affected the modern
imagination.