Rising ideas in the sky of knowledge

The constellated sky has never ceased to foster the enthusiasm of men and women in search of illumination. In his Theogony, Hesiod tells us how Gaea, the wide-bosomed Earth, arose from the vast and dark Chaos, accompanied by Eros. Gaea first bore Uranus, the starry heaven, then the barren waters of the sea.

Almost three millennia separate this genealogy of the gods from the modern idea of the expanding cosmos and the stellar origins of human matter, summed up so concisely in the two statements:

• the Universe is expanding;

• we are made from star dust.

What brought human beings to invent cosmology and relegate the celestial genealogy of the gods to oblivion? Is there no more drama in the heavens? No genesis?

The stars are just the punctuation in the text of the heavenly narrative. And yet, in our recitation, we claim to know the whole history of the Universe. Formulating its plot on the stage provided by the space–time of matter, astrophysics expresses a cosmic vision as well as a body of scientific thought. The sky is a palimpsest. Under the first visible writing, the starry sky, modern astronomy has managed to bring out, at least in part, very ancient hieroglyphics and original engravings.

From Hesiod to Aristotle, from Aristotle to Galileo, from Galileo to Einstein, the Universe has undergone repeated mental reform. Visionaries of infinity have replaced poets and men of God.